From scott93727 from aol.com Sat Nov 3 07:17:58 2007 From: scott93727 from aol.com (Scott) Date: Sat Nov 3 20:33:11 2007 Subject: [Neuroscience] grass 9A5 amps (EEG) Message-ID: <1194092278.946684.315430@i38g2000prf.googlegroups.com> I have a bunch of grass 9A5 amps (EEG) and would like to modify some of them for portable use in the field, do you know where I can get rear connectors and the printouts specs, for power and input / outpputs, thank you very much. (scott93727@aol.com) Scott From ayaz_siddiqi from yahoo.com Tue Nov 6 01:58:38 2007 From: ayaz_siddiqi from yahoo.com (ayaz) Date: Tue Nov 6 09:07:14 2007 Subject: [Neuroscience] Effects of weak electric fields on the activity of neurons and neuronal networks Message-ID: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> if you want the full text, you'll have to pay for it... http://rpd.oxfordjournals.org/cgi/content/abstract/106/4/321?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexactfulltext=and&searchid=1077029641510_173&stored_search=&FIRSTINDEX=0&sortspec=relevance&volume=106&firstpage=321&resourcetype=1&journalcode=rpd Radiation Protection Dosimetry 106:321-323 (2003) ? 2003 Oxford University Press Effects of weak electric fields on the activity of neurons and neuronal networks J.G.R. Jefferys, J. Deans, M. Bikson and J. Fox Electric fields applied to brain tissue will affect cellular properties. They will hyperpolarise the ends of cells closest to the positive part of the field, and depolarise ends closest to the negative. In the case of neurons this affects excitability. How these changes in transmembrane potential are distributed depends on the length constant of the neuron, and on its geometry; if the neuron is electrically compact, the change in transmembrane potential becomes an almost linear function of distance in the direction of the field. Neurons from the mammalian hippocampus, maintained in tissue slices in vitro, are significantly affected by fields of around 1-5 Vm-1. From nottoooily from hotmail.com Tue Nov 6 04:53:27 2007 From: nottoooily from hotmail.com (nottoooily@hotmail.com) Date: Tue Nov 6 09:07:18 2007 Subject: [Neuroscience] Re: Effects of weak electric fields on the activity of neurons and neuronal networks In-Reply-To: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> References: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> Message-ID: <1194342807.463293.295300@i13g2000prf.googlegroups.com> Oh dear. I heard about a brain cancer treatment which uses electric fields to damage cell reproduction. It'll be a pity if this also makes people stupid. On Nov 6, 7:58 pm, ayaz wrote: > > Electric fields applied to brain tissue will affect cellular > properties. They will hyperpolarise the ends of cells closest to the > positive part of the field, and depolarise ends closest to the > negative. In the case of neurons this affects excitability. How these > changes in transmembrane potential are distributed depends on the > length constant of the neuron, and on its geometry; if the neuron is > electrically compact, the change in transmembrane potential becomes an > almost linear function of distance in the direction of the field. > Neurons from the mammalian hippocampus, maintained in tissue slices in > vitro, are significantly affected by fields of around 1-5 Vm-1. From useful_infos from yahoo.com Tue Nov 6 07:49:33 2007 From: useful_infos from yahoo.com (Joe) Date: Tue Nov 6 09:07:21 2007 Subject: [Neuroscience] The 12 cranial nerves Message-ID: <1194353373.169449.111160@z9g2000hsf.googlegroups.com> Here's how to remember them. This is the non-German non-hops non- vegetable version. http://home.comcast.net/~plutarch/ooottafvgvah.html From andy.resnick from op.case.edu Tue Nov 6 09:28:15 2007 From: andy.resnick from op.case.edu (Andy Resnick) Date: Tue Nov 6 09:07:25 2007 Subject: [Neuroscience] Re: Effects of weak electric fields on the activity of neurons and neuronal networks In-Reply-To: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> References: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> Message-ID: ayaz wrote: > if you want the full text, you'll have to pay for it... > > http://rpd.oxfordjournals.org/cgi/content/abstract/106/4/321?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexactfulltext=and&searchid=1077029641510_173&stored_search=&FIRSTINDEX=0&sortspec=relevance&volume=106&firstpage=321&resourcetype=1&journalcode=rpd > > Radiation Protection Dosimetry 106:321-323 (2003) > ? 2003 Oxford University Press > > Effects of weak electric fields on the activity of neurons and > neuronal networks > J.G.R. Jefferys, J. Deans, M. Bikson and J. Fox > > Electric fields applied to brain tissue will affect cellular > properties. They will hyperpolarise the ends of cells closest to the > positive part of the field, and depolarise ends closest to the > negative. In the case of neurons this affects excitability. How these > changes in transmembrane potential are distributed depends on the > length constant of the neuron, and on its geometry; if the neuron is > electrically compact, the change in transmembrane potential becomes an > almost linear function of distance in the direction of the field. > Neurons from the mammalian hippocampus, maintained in tissue slices in > vitro, are significantly affected by fields of around 1-5 Vm-1. Remarkable. They present no actual data, summarize previous results with no way to decipher what was actually done, and make numerous unsubstantiated claims. For example: "More importantly, we were able to measure that transmembrane potential at the cell body changed by an average of 0.12 mV for each V m1 of applied field(16)A" AFAIK, the action potential is around 100 mV- so they claim a 0.1% effect is meaningful and statistically significant. But it *is* open source, so some would say this is a model effort. -- Andrew Resnick, Ph.D. Department of Physiology and Biophysics Case Western Reserve University From r_s_norman from _comcast.net Tue Nov 6 09:11:09 2007 From: r_s_norman from _comcast.net (r norman) Date: Tue Nov 6 23:26:08 2007 Subject: [Neuroscience] Re: Effects of weak electric fields on the activity of neurons and neuronal networks References: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> Message-ID: <56s0j3hu9vpd36nk24mp2kcv0dv1j2nklg@4ax.com> On Tue, 06 Nov 2007 09:28:15 -0500, Andy Resnick wrote: >ayaz wrote: >> if you want the full text, you'll have to pay for it... >> >> http://rpd.oxfordjournals.org/cgi/content/abstract/106/4/321?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&andorexactfulltext=and&searchid=1077029641510_173&stored_search=&FIRSTINDEX=0&sortspec=relevance&volume=106&firstpage=321&resourcetype=1&journalcode=rpd >> >> Radiation Protection Dosimetry 106:321-323 (2003) >> ? 2003 Oxford University Press >> >> Effects of weak electric fields on the activity of neurons and >> neuronal networks >> J.G.R. Jefferys, J. Deans, M. Bikson and J. Fox >> >> Electric fields applied to brain tissue will affect cellular >> properties. They will hyperpolarise the ends of cells closest to the >> positive part of the field, and depolarise ends closest to the >> negative. In the case of neurons this affects excitability. How these >> changes in transmembrane potential are distributed depends on the >> length constant of the neuron, and on its geometry; if the neuron is >> electrically compact, the change in transmembrane potential becomes an >> almost linear function of distance in the direction of the field. >> Neurons from the mammalian hippocampus, maintained in tissue slices in >> vitro, are significantly affected by fields of around 1-5 Vm-1. > >Remarkable. They present no actual data, summarize previous results >with no way to decipher what was actually done, and make numerous >unsubstantiated claims. > >For example: > >"More importantly, we were able to measure that transmembrane >potential at the cell body changed by an average >of 0.12 mV for each V m 1 of applied field(16)A" > >AFAIK, the action potential is around 100 mV- so they claim a 0.1% >effect is meaningful and statistically significant. > >But it *is* open source, so some would say this is a model effort. If you look at the papers that cite the particular one you find some truly experimental work that suggests a true effect. For example: T. Radman, Y. Su, J. H. An, L. C. Parra, and M. Bikson Spike Timing Amplifies the Effect of Electric Fields on Neurons: Implications for Endogenous Field Effects J. Neurosci., March 14, 2007; 27(11): 3030 - 3036. "We found that a 1 mV/mm uniform field induced on average a transmembrane potential change of 0.1 mV. Compared with the scale of depolarization necessary to bring a neuron from rest to threshold (15 mV), these fields were previously considered insignificant with respect to action potential initiation. Previous action potential threshold studies identified changes attributable to electric fields of <5 mV/mm (Jefferys, 1981). Rather than spike generation, here we demonstrated changes in timing, consistent with the proposed amplification mechanism. The present results provide a potential mechanism for the effects on network spike timing demonstrated previously in vitro with exogenous uniform fields as low as 0.1 mV/mm (Deans et al., 2003; Francis et al., 2003; Fujisawa et al., 2004) and in vivo with calculated fields of 1.2 mV/mm (Marshall et al., 2006). " Just how significant these effects are in a free-living animal moving around in an external field so that any small effect is variable and transient is another question. Fields of 1 mV/mm (1 V/m) are pretty strong because tissue is a relatively good conductor, resistivity = 60 ohm-cm. That means that to get a field of 1 mV/mm = 10 mV/cm you need a current flow of 0.17 mA/sq-cm. I haven't calculated what kind of external electric field would be necessary to produce that type of current flow in a volume as large as a human head, but it must be rather large. I can say from direct experimental measurements that you do NOT see currents and fields like that in ordinary neurophysiological experiments in rooms filled with electronic equipment even if the experimental setup is not enclosed in a Faraday cage. The purpose of the cage is to eliminate potentials induced by external fields across relatively high resistance electrodes, not potentials induced within a saline bath. From kidsdoc2000 from hotmail.com Tue Nov 6 18:25:32 2007 From: kidsdoc2000 from hotmail.com (Jeff) Date: Tue Nov 6 23:26:16 2007 Subject: [Neuroscience] Re: The 12 cranial nerves In-Reply-To: <13j173cahrahr99@corp.supernews.com> References: <1194353373.169449.111160@z9g2000hsf.googlegroups.com> <13j173cahrahr99@corp.supernews.com> Message-ID: Steven Bornfeld wrote: > Joe wrote: >> Here's how to remember them. This is the non-German non-hops non- >> vegetable version. >> >> http://home.comcast.net/~plutarch/ooottafvgvah.html >> > > > We heard variants of this, but of course they taught us the "on old > Olympus Towering Top..." > At the medical school bookstore, there was a book filled with > mnemonics. > Lets see if I remember the mnemonic for whether the cranial nerves > are motor, sensory, or mixed: Some say make money but my mother says > Brigitte Bardot Makes More...is that right? ;-) > > Steve Actually, the OP hopes to make more money. Notice all the ads. He didn't do this for free. Jeff From dentaltwinmung from earthlink.net Tue Nov 6 19:23:08 2007 From: dentaltwinmung from earthlink.net (Steven Bornfeld) Date: Tue Nov 6 23:26:20 2007 Subject: [Neuroscience] Re: The 12 cranial nerves In-Reply-To: References: <1194353373.169449.111160@z9g2000hsf.googlegroups.com> <13j173cahrahr99@corp.supernews.com> Message-ID: <13j21bgd2cle876@corp.supernews.com> Jeff wrote: > > Actually, the OP hopes to make more money. Notice all the ads. He didn't > do this for free. > > Jeff Well, dag nab it! And to think, I didn't click through. Obviously, I'm not the ideal viewer. make more money--which cranial nerves are those? Incidentally, 34 years later, I still remember the mnemonic we used when dissecting the brachial plexus of nerves: Rats Take Big Craps Noontime. Now, if only I remembered what it stood for... Steve From dentaltwinmung from earthlink.net Tue Nov 6 11:55:04 2007 From: dentaltwinmung from earthlink.net (Steven Bornfeld) Date: Tue Nov 6 23:27:12 2007 Subject: [Neuroscience] Re: The 12 cranial nerves In-Reply-To: <1194353373.169449.111160@z9g2000hsf.googlegroups.com> References: <1194353373.169449.111160@z9g2000hsf.googlegroups.com> Message-ID: <13j173cahrahr99@corp.supernews.com> Joe wrote: > Here's how to remember them. This is the non-German non-hops non- > vegetable version. > > http://home.comcast.net/~plutarch/ooottafvgvah.html > We heard variants of this, but of course they taught us the "on old Olympus Towering Top..." At the medical school bookstore, there was a book filled with mnemonics. Lets see if I remember the mnemonic for whether the cranial nerves are motor, sensory, or mixed: Some say make money but my mother says Brigitte Bardot Makes More...is that right? ;-) Steve From j_hasenkam from yahoo.com.au Wed Nov 7 19:48:53 2007 From: j_hasenkam from yahoo.com.au (John H.) Date: Thu Nov 8 12:29:10 2007 Subject: [Neuroscience] Re: Effects of weak electric fields on the activity of neurons and neuronal networks In-Reply-To: <56s0j3hu9vpd36nk24mp2kcv0dv1j2nklg@4ax.com> References: <1194332318.689188.90720@z9g2000hsf.googlegroups.com> <56s0j3hu9vpd36nk24mp2kcv0dv1j2nklg@4ax.com> Message-ID: <1194482933.850736.259670@y27g2000pre.googlegroups.com> There is something strange going on with these sort of studies. Had a good look at them a few years ago and clearly there is an effect. Additionally, pulsed magnetic fields have been tried as a therapeutic measure for a variety of neurological conditions and these experiments do suggest promise. A friend of mine who is a physiotherapist has suggested to me that physios have been using magnetic fields for years, recently I came across a trial which suggested promise in this regard. One of the stranger effects noted from magnetic fields is the impact on mast cells, a matter I was particularly interested in because there are neuroimmune implications. Sadly this area of research tends to be neglected, possibly because it strikes too many people are spooky. Why ignore such things? ECT is arguably the quickest way to reduce depression with psychotic features and we still don't have a clue as to what is going on there. Pity it can also damage the hippocampus ... . John. On Nov 7, 12:11 am, r norman wrote: > On Tue, 06 Nov 2007 09:28:15 -0500, Andy Resnick > > > > > > wrote: > >ayaz wrote: > >> if you want the full text, you'll have to pay for it... > > >>http://rpd.oxfordjournals.org/cgi/content/abstract/106/4/321?maxtosho... > > >> Radiation Protection Dosimetry 106:321-323 (2003) > >> ? 2003 Oxford University Press > > >> Effects of weak electric fields on the activity of neurons and > >> neuronal networks > >> J.G.R. Jefferys, J. Deans, M. Bikson and J. Fox > > >> Electric fields applied to brain tissue will affect cellular > >> properties. They will hyperpolarise the ends of cells closest to the > >> positive part of the field, and depolarise ends closest to the > >> negative. In the case of neurons this affects excitability. How these > >> changes in transmembrane potential are distributed depends on the > >> length constant of the neuron, and on its geometry; if the neuron is > >> electrically compact, the change in transmembrane potential becomes an > >> almost linear function of distance in the direction of the field. > >> Neurons from the mammalian hippocampus, maintained in tissue slices in > >> vitro, are significantly affected by fields of around 1-5 Vm-1. > > >Remarkable. They present no actual data, summarize previous results > >with no way to decipher what was actually done, and make numerous > >unsubstantiated claims. > > >For example: > > >"More importantly, we were able to measure that transmembrane > >potential at the cell body changed by an average > >of 0.12 mV for each V m > > 1 of applied field(16)A" > > > > >AFAIK, the action potential is around 100 mV- so they claim a 0.1% > >effect is meaningful and statistically significant. > > >But it *is* open source, so some would say this is a model effort. > > If you look at the papers that cite the particular one you find some > truly experimental work that suggests a true effect. > > For example: > T. Radman, Y. Su, J. H. An, L. C. Parra, and M. Bikson > Spike Timing Amplifies the Effect of Electric Fields on > Neurons: Implications for Endogenous Field Effects > J. Neurosci., March 14, 2007; 27(11): 3030 - 3036. > "We found that a 1 mV/mm uniform field induced on average a > transmembrane potential change of 0.1 mV. Compared with the scale of > depolarization necessary to bring a neuron from rest to threshold (15 > mV), these fields were previously considered insignificant with > respect to action potential initiation. Previous action potential > threshold studies identified changes attributable to electric fields > of <5 mV/mm (Jefferys, 1981). Rather than spike generation, here we > demonstrated changes in timing, consistent with the proposed > amplification mechanism. The present results provide a potential > mechanism for the effects on network spike timing demonstrated > previously in vitro with exogenous uniform fields as low as 0.1 mV/mm > (Deans et al., 2003; Francis et al., 2003; Fujisawa et al., 2004) and > in vivo with calculated fields of 1.2 mV/mm (Marshall et al., 2006). " > > Just how significant these effects are in a free-living animal moving > around in an external field so that any small effect is variable and > transient is another question. Fields of 1 mV/mm (1 V/m) are pretty > strong because tissue is a relatively good conductor, resistivity = 60 > ohm-cm. That means that to get a field of 1 mV/mm = 10 mV/cm you need > a current flow of 0.17 mA/sq-cm. I haven't calculated what kind of > external electric field would be necessary to produce that type of > current flow in a volume as large as a human head, but it must be > rather large. I can say from direct experimental measurements that > you do NOT see currents and fields like that in ordinary > neurophysiological experiments in rooms filled with electronic > equipment even if the experimental setup is not enclosed in a Faraday > cage. The purpose of the cage is to eliminate potentials induced by > external fields across relatively high resistance electrodes, not > potentials induced within a saline bath.- Hide quoted text - > > - Show quoted text - From docks from abv.bg Thu Nov 8 11:39:08 2007 From: docks from abv.bg (Plamen Simeonov) Date: Thu Nov 8 12:29:24 2007 Subject: [Neuroscience] EMG Cadwell 5200A Message-ID: <481041580.306401194539948400.JavaMail.nobody@mail44.abv.bg> I am a doctor-specialist of neurology and I am from Bulgaria.I have the s= ame EMG-Cadwell 5200A but the printer is out of order.I have a need from a = program wich to connect the Cadwell with a computer working with DOS or WIN= DOWS.I want to store and print the EMG with a laser printer.I will be very = thankfull and glad to help me if you want with an information. =20 ----------------------------------------------------------------- =C5=ED=E5=F0=E3=E8=FF=F2=E0 =E5 =E2 =F7=E5=F0=E2=E5=ED=EE =ED=E0 www.axn-re= d.com !From morriswatermaze from gmail.com Fri Nov 9 00:16:05 2007 From: morriswatermaze from gmail.com (morriswatermaze@gmail.com) Date: Sat Nov 10 16:22:51 2007 Subject: [Neuroscience] Morris Water Maze Message-ID: <933f83b0711082116x374e5e7dida0d9cf5febee134@mail.gmail.com> What are the most important behaviors to characterize in the Morris Water Maze? (i.e. is thigmotaxis more important than scanning behavior?) Thanks! From rbf from inf.ed.ac.uk Mon Nov 12 13:59:55 2007 From: rbf from inf.ed.ac.uk (Bob Fisher) Date: Mon Nov 12 16:29:47 2007 Subject: [Neuroscience] ANN: 1 year MS/MSc course in Informatics at Edinburgh University Message-ID: The School of Informatics at Edinburgh University offers highly praised 1 year MSc (MS) degrees in Informatics, Artificial Intelligence, Cognitive Science and Computer Science. You will specialise in * Bioinformatics * Computational Systems Biology We also offer other specialities: * Analytical and Scientific Databases * Computer Systems and Software Engineering * Fundamentals of High Performance Computing Systems * Geoinformatics * Intelligent Robotics * Knowledge Representation and Reasoning * Learning from Data * Natural Language and Language Engineering * Neural Computation and Neuroinformatics * Theoretical Computer Science The course consists of 6 months taught work, with modules selected from over 50 modules at masters level, followed by a supervised 6 month project. Studentships are available for students in some of the above specialties. More about the course can be seen at: http://www.inf.ed.ac.uk/postgraduate/msc.html Dissertations from previous projects can be seen at: http://www.inf.ed.ac.uk/publications/thesis/msc.html The School of Informatics received an excellent rating in the most recent SHEFC Teaching Quality Assessment exercise. In the UK, the higher education funding bodies carry out a Research Assessment Exercise (RAE). The last RAE exercise was held in 2001 and the University of Edinburgh was the only university in the UK awarded the top 5*A rating for Computer Science. Application ================ You must have a first or upper second class honours degree or its equivalent (A or B GPA average), normally in an area of Informatics, such as Artificial Intelligence, Cognitive Science or Computer Science. You must have experience in computer programming. Applicants with degrees in these disciplines will also be considered: Education, Electrical Engineering, Psychology, Mathematics, Philosophy, and Physics. See here about application procedures: http://www.inf.ed.ac.uk/postgraduate/apply.html From gmsizemore2 from yahoo.com Wed Nov 14 15:41:23 2007 From: gmsizemore2 from yahoo.com (Glen M. Sizemore) Date: Wed Nov 14 16:01:04 2007 Subject: [Neuroscience] Re: pointers to further study References: <1195071713.129643.157420@50g2000hsm.googlegroups.com> Message-ID: <473b5d74$0$20636$ed362ca5@nr2.newsreader.com> "neunetllc" wrote in message news:1195071713.129643.157420@50g2000hsm.googlegroups.com... > hi folks. recently i wrote in my blog about questioning the > fundamental assumptions we make about perceptions... > > http://zeni.mobi/node/160 > > i was wondering, based on your review, what path would you direct me > to further study in the broad, diverse field of neuroscience, to get a > better idea of how fundamental cognitive constructs are modeled? > > ty, jay > What is a "cognitive construct"? From j_hasenkam from yahoo.com.au Wed Nov 14 22:33:16 2007 From: j_hasenkam from yahoo.com.au (John H.) Date: Thu Nov 15 13:04:01 2007 Subject: [Neuroscience] Re: pointers to further study References: <1195071713.129643.157420@50g2000hsm.googlegroups.com> Message-ID: <3a96cc13-9bc7-455b-83a8-f2284fbf148c@i12g2000prf.googlegroups.com> On Nov 15, 6:21 am, neunetllc wrote: > hi folks. recently i wrote in my blog about questioning the > fundamental assumptions we make about perceptions... > > http://zeni.mobi/node/160 > > i was wondering, based on your review, what path would you direct me > to further study in the broad, diverse field of neuroscience, to get a > better idea of how fundamental cognitive constructs are modeled? > > ty, jay If and when someone works out what a "fundamental cognitive construct" is, you'll be sure to hear about it. Don't hold your breath. John. From at from at.at Thu Nov 15 12:27:51 2007 From: at from at.at (RK) Date: Thu Nov 15 19:59:49 2007 Subject: [Neuroscience] Brain cells? Message-ID: <473c8178$0$2094$edfadb0f@dtext02.news.tele.dk> Is it true that brains cells isn't replaced, and if so, how about this? I read in Dean Radins: 'The conscious universe' that the molecules in the brain are replaced 10.000 times in a life time'. Can anybody here explain this to a layman? From r_s_norman from _comcast.net Thu Nov 15 16:52:41 2007 From: r_s_norman from _comcast.net (r norman) Date: Thu Nov 15 19:59:54 2007 Subject: [Neuroscience] Re: Brain cells? References: <473c8178$0$2094$edfadb0f@dtext02.news.tele.dk> Message-ID: On Thu, 15 Nov 2007 18:27:51 +0100, "RK" wrote: >Is it true that brains cells isn't replaced, and if so, how about this? I >read in Dean Radins: 'The conscious universe' that the molecules in the >brain are replaced 10.000 times in a life time'. Can anybody here explain >this to a layman? > When you say "brain cells aren't replaced" you really mean that neurons don't divide to produce new cells. It doesn't mean that you constantly update and replace the specific parts of the old cells. It is like fixing your car, replacing all the parts including the engine and even the body compared with going out and buying a new car. From nelsa from cneuro.edu.cu Fri Nov 16 09:22:23 2007 From: nelsa from cneuro.edu.cu (Nelsa Echevarria Alvarez) Date: Fri Nov 16 10:28:05 2007 Subject: [Neuroscience] RV: 4th Cuban Congress & First Ibero-American Workshop of Clinical Neurophysiology Web Site http://www.cneuro.edu.cu/ http://cencomed.sld.cu/neurofisiologia08/ Message-ID: <9F00237754801B43A032F70B888F05416FE178@correo.cneuro.edu.cu> Espa?ol- English Del 11 al 14 de Marzo del 2008, se celebrar? en Varadero, Cuba, el 4to Congreso Cubano y Primer Taller Ibero-Americano de Neurofisiolog?a Cl?nica. Nos dirigimos a usted, en nombre de la Sociedad Cubana de Neurofisiolog?a Cl?nica y el Centro de Neurociencias de Cuba, para solicitar se publique el anuncio de nuestro Congreso en su Revista. Le adjuntamos el mensaje largo que pudi?ramos publicar. El mensaje corto ser?a: 4th Cuban Congress & First Ibero-American Workshop of Clinical Neurophysiology March 11-14, 2008 "Plaza America" Convention Center. Varadero, Cuba President of the Congress: Calixto Machado Curbelo, MD, PhD President of the Scientific Committee: Pedro Vald?s Sosa, MD, PhD http://www.cneuro.edu.cu http://cencomed.sld.cu/neurofisiologia08/ Contact us: Claudia Torn? Fern?ndez Scientific Organization Group Organizing Committee 4th Cuban Congress & First Ibero-Latin American Workshop of Clinical Neurophysiology Web Site: http://www.cneuro.edu.cu http://cencomed.sld.cu/neurofisiologia08/ Cuban Neuroscience Center Calle 25 #15202 esquina158 Cubanac?n Playa Work Phone: 2086321 email: claudia@cneuro.edu.cu claudia17387@yahoo.com Deseamos nos informe, si es necesario alg?n tr?mite oficial para realizar este anuncio. >From 11 to March 14, 2008, the 4th Cuban Congress and First Ibero-American Workshop of Clinical Neurophysiology will be held in Varadero, Cuba. We are writing you on behalf of the Cuban Society of Clinical Neurophysiology and the Cuban Neurosciences Center for requesting issuance of the notice of our Congress in you magazine. We attached the complete message that could be published. The short announcement would be: 4th Cuban Congress & First Ibero-American Workshop of Clinical Neurophysiology March 11-14, 2008 "Plaza America" Convention Center. Varadero, Cuba President of the Congress: Calixto Machado Curbelo, MD, PhD President of the Scientific Committee: Pedro Vald?s Sosa, MD, PhD http://www.cneuro.edu.cu http://cencomed.sld.cu/neurofisiologia08/ Contact us: Claudia Torn? Fern?ndez Scientific Organization Group Organizing Committee 4th Cuban Congress & First Ibero-Latin American Workshop of Clinical Neurophysiology Web Site: http://www.cneuro.edu.cu http://cencomed.sld.cu/neurofisiologia08/ Cuban Neuroscience Center Calle 25 #15202 esquina158 Cubanac?n Playa Work Phone: 2086321 email: claudia@cneuro.edu.cu claudia17387@yahoo.com We wish to inform us if a procedure is necessary to make this official announcement. Gertrudis de los ?ngeles Hern?ndez Gonz?lez, MD,MsC. Neurologist. Vice President Organizing Committee 4th Cuban Congress & First Ibero-American Workshop of Clinical Neurophysiology. Web site: http://www.cneuro.edu.cu/ http://cencomed.sld.cu/neurofisiologia08/ Clinical Neuroimaging Group. Cuban Human Brain Mapping Project Cuban Neuroscience Center. Address: Ave 25 #15202 esquina 158, Cubanac?n, Playa, Area Code 11600 Ciudad Habana, CUBA, P.O.B 6412 /6414 e-mail: gertrudis@cneuro.edu.cu , gertru35@yahoo.es , gertruhg@infomed.sld.cu Work Phone: (53)-7-208 6321 (53)-7-208 52 96 From p_johns from londonwc1.clara.co.uk Sun Nov 18 15:38:58 2007 From: p_johns from londonwc1.clara.co.uk (Dr Paul Johns) Date: Sun Nov 18 16:29:14 2007 Subject: [Neuroscience] Brain anatomy Message-ID: <1195418393.15727.0@proxy02.news.clara.net> If you are interested in functional neuroanatomy, there is a 3-day human brain anatomy course in central London in April 2008 that is suitable for undergraduates / postgraduates in neuroscience, psychology or medicine: http://www.neurocourses.com/. Dr Paul Johns From hougaard from language.sdu.dk Mon Nov 19 09:55:49 2007 From: hougaard from language.sdu.dk (Anders Hougaard) Date: Mon Nov 19 14:23:29 2007 Subject: [Neuroscience] LCM3: 3rd cfp References: <9F00237754801B43A032F70B888F05416FE178@correo.cneuro.edu.cu> Message-ID: CONFERENCE: LANGUAGE, CULTURE AND MIND 3 Odense, 14-16th July 2008 3RD CALL FOR INDIVIDUAL PAPERS NEW! LCM III satellite event: Empirical Methods in Cognitive Linguistics, 7-11th July. The LCM committee and local organizers call for theme session proposals for the third conference in the series Language, Culture and Mind. The conference will be held in modern and comfortable conference facilities in ODENSE 14TH-16TH JULY, 2008. The conference aims at establishing an interdisciplinary forum for an integration of cognitive, social and cultural perspectives in theoretical and empirical studies of language and communication. The special theme of the conference is Social Life and Meaning Construction. We call for contributions from scholars and scientists in anthropology, biology, linguistics, philosophy, psychology, semiotics, semantics, social interaction, discourse analysis, cognitive and neuroscience, who wish both to impart their insights and findings, and learn from other disciplines. Preference will be given to submissions which emphasize interdisciplinarity, the interaction between social life, culture, mind and language, and/or multi-methodological approaches in language and communication sciences. Description of the LCM conference series: see bottom. DATES: * First call for Theme Sessions: April 1, 2007 * Second call for Theme Sessions: May 1, 2007 * Third call for Theme Sessions: June 1, 2007 * Deadline for Theme Sessions submissions: September 1, 2007 (Extended) * Notification for Theme Sessions : November 1, 2007 (Extended) * First call for Individual Papers and Posters: September 1, 2007 * Second call for Individual Papers and Posters: October 1, 2007 * Third call for Individual Papers and Posters: November 1, 2007 (Delayed) * Deadline for Individual Paper and Poster submissions: January 1, 2008 * Deadline for submitting papers for theme sessions: February 1, 2008 * Notification for Individual Paper, Theme Session paper and Poster submissions: March 1, 2008 SUBMISSION GUIDELINES: Max. 500 words (including references) To be submitted to lcm@language.sdu.dk Submissions will be evaluated according to their * Relevance * Quality * Coherence * Originality PLENARY SPEAKERS: Michael Chandler (University of British Columbia) Alessandro Duranti (University of California at Los Angeles) Derek Edwards (University of Loughborough) Marianne Gullberg (Max Planck Institute for Psycholinguistics) Esa Itkonen (University of Turku) Meredith Williams (Johns Hopkins University) CONFERENCE WEBSITE: http://www.lcm.sdu.dk NEW! THEME SESSIONS: Titel: "Social Construction, Psychological Discourse and Neuroimaging" Organizer: Adam Wallwork Titel: "'Doing Science' as a Collaborative Accomplishment of the Mind as Discourse-in-Interaction" Organizer: Gudrun Ziegler Titel: "Lectal and Multilingual Variation: Cognitive and Social Dimensions" Organizers: Raphael Berthele, Dirk Geeraerts, Gitte Kristiansen, Yves Peirsman Titel: "Language, Sociality, and Mind: Lessons from a neurodegenerative disorder" Organizer: Andrea W. Mates Titel:"Bridging the Gap in Cultural Studies: From meaning construction to (inter-)cultural communicative competence" Organizer: Izaskun Elorza & Ovid Carbonell Titel: "Intersubjectivity: Between Personal Experience and Social Life" Organizers: Timothy P. Racine & Jordan Zlatev Titel: "Situating understanding, perception, in social interaction" Organizer: Domenic Berducci Titel: "Chinese Language, Cultural Keywords and Ethno-philosophy" Organizer: Adrian Tien Titel: "(Cross-Cultural Communication)" Organizer: Bert Peeters Titel: "Communicating and Interpreting Policy Meaning" Organizer: Alan Cienki & Dvora Yanow Titel: "Language and Cultural Change in Immigrant and Aboriginal Communities: Transformations at the culture, language, and mind interface" Organizers: Michael Chandler & Cynthia Lightfoot Titel: "Social Life and Meaning Construction" Organizer Paul Thibault Titel: "Discourse and psychology: Emotion, knowledge and institution interaction" Organizer: Jonathan Potter Titel: "Situated, distributed cognition and social structure of shared task performance in high-risk workplaces" Organizer: Lisa Loloma Froholdt Titel: "Social Interaction, Cognition, and Intersubjectivity" Organizers: Thomas Wiben Jensen, Anders R Hougaard & Gitte R Hougaard NEW! SATELLITE EVENT LCM III satellite event: Empirical Methods in Cognitive Linguistics, 7-11th July Organizers: Monica Gonzalez Marquez,Raymond Becker, Anders R Hougaard, Gitte R Hougaard and Todd Oakley More Information follows later! EARLIER LCM CONFERENCES: 1st LCM conference: Portsmouth 2004 2nd LCM conference: Paris 2006 > THE INTERNATIONAL LCM COMMITTEE: Raphael Berthele Carlos Cornejo Caroline David Merlin Donald Barbara Fultner Anders R. Hougaard Jean Lass?gue John A Lucy Aliyah Morgenstern Eve Pinsker Vera da Silva Sinha Chris Sinha THE LOCAL ORGANIZING COMMITTEE: Center for Social Practises and Cognition (SoPraCon): Rineke Brouwer Dennis Day Annette Grindsted Anders R. Hougaard Gitte R. Hougaard (Director) Kristian Mortensen SCIENTIFIC COMMITTEE Anne Salazar Orvig Meredith Williams Todd Oakley Jonathan Potter Robin Wooffitt Alan Cienki Cornellia M?ller Ewa Dabrowska Edy Veneziano Shaun Gallagher Edwin Hutchins Johannes Wagner THE LCM CONFERENCES: The goals of LCM conferences are to contribute to situating the study of language in a contemporary interdisciplinary dialogue, and to promote a better integration of cognitive and cultural perspectives in empirical and theoretical studies of language. Human natural languages are biologically based, cognitively motivated, affectively rich, socially shared, grammatically organized symbolic systems. They provide the principal semiotic means for the complexity and diversity of human cultural life. As has long been recognized, no single discipline or methodology is sufficient to capture all the dimensions of this complex and multifaceted phenomenon, which lies at the heart of what it is to be human. Theories of cognition and perception, and their neural foundations, are central to many current approaches in language science. However, a genuinely integrative perspective requires that attention also be paid to the foundations of cultural life in social interaction, empathy, mimesis, intersubjectivity, dialogicality, normativity, agentivity and narrativity. Significant theoretical, methodological and empirical advancements across relevant disciplines now provide a realistic basis for such a broadened perspective. This conference will articulate and discuss approaches to human natural language and to diverse genres of language activity which aim to integrate its cultural, social, cognitive, affective and bodily foundations. We call for contributions from scholars and scientists in anthropology, biology, linguistics, philosophy, psychology, semiotics, semantics, discourse analysis, cognitive and neuroscience, who wish both to share their insights and findings, and learn from other disciplines. Preference will be given to submissions which emphasize interdisciplinarity, the interaction between culture, mind and language, and/or multi-methodological approaches in language sciences. ***** Anders R. Hougaard Assistant professor, PhD Center for Social Practises and Cognition (SoPraCon) Institute of Language and Communication University of Southern Denmark, Odense hougaard@language.sdu.dk Phone: +45 65503154 Fax: + 45 65932483. From hotaling from andromeda.rutgers.edu Thu Nov 15 12:36:18 2007 From: hotaling from andromeda.rutgers.edu (Beth Hotaling) Date: Tue Nov 20 11:39:54 2007 Subject: [Neuroscience] [long, off topic info] decussation problem Message-ID: <000001c82ab9$02fb7750$33210680@RFPMachine> to ken collins Decussation would allow an animal whose left brain is asleep (left eye closed) to sense danger or obstacles approaching its left side. Left side of brain then wakes up and animal takes evasive action. The animal's open right eye protects the right side. Just a thought! EC Hotaling From j_hasenkam from yahoo.com.au Sun Nov 25 23:17:31 2007 From: j_hasenkam from yahoo.com.au (John H.) Date: Mon Nov 26 10:07:03 2007 Subject: [Neuroscience] Re: Cannabis and the Brain: A User's Guide References: Message-ID: On Nov 24, 6:25 am, Saint Isadore Patron Saint of the Internet wrote: > http://www.lewrockwell.com/armentano-p/armentano-p10.htm > > If you seek the REAL truth on this - then go to the above link. > > Toke On! > > - Tom > (A Mendocino county Medical Marijuana - user, cultivator, supporter) Known all in the link for years, the literature screams it out, very concordant, particularly with respect to the little known functions of the CB2 receptor. Doesn't change the way people think though, the truth rarely does, at least in the short term. However I reject the idea that long term chronic use is not without risks. I'm yet to meet such a stoner who didn't show the deleterious effects of the same. It's not that it causes brain damage but that it changes brain chemistry so much that stoners simply cannot function as well as they could. This, however, becomes more a moral question than a medical one. Do we really want the world filled with workaholics? No, our culture of work is wrecking the planet. John. From S.Pourcel from brighton.ac.uk Tue Nov 27 03:31:01 2007 From: S.Pourcel from brighton.ac.uk (S.Pourcel@brighton.ac.uk) Date: Tue Nov 27 09:10:55 2007 Subject: [Neuroscience] ***EXTENDED DEADLINE*** Language, Communication and Cognition Conference (Brighton 2008) Message-ID: *************EXTENDED ABSTRACT SUBMISSION DEADLINE*************** Due to multiple requests for further time to submit abstracts, the deadline for submission to the Conference on Language, Communication and Cognition (Brighton Aug 4-7 2008) has been extended until Sunday 2nd December 2007. ******************************************************************************* Conference on LANGUAGE, COMMUNICATION AND COGNITION University of Brighton, August 4th-7th 2008, Brighton, UK Website: www.languageandcognition.net The conference on Language, Communication and Cognition aims to promote an interdisciplinary, comparative, multi-methodological approach to the study of language, communication and cognition, informed by method and practice as developed in Cognitive Linguistics. The objective is to contribute to our understanding of language as a key aspect of human cognition, using converging and multi-disciplinary methodologies, based upon cross-linguistic, cross-cultural, and cross-population comparisons. The conference will address the following themes: -Language, creativity and imagination -Language in use -Meaning and grammar -Communication, conceptualisation and gesture -Language and its influence on thought -Language acquisition and conceptual development -Origins and evolution of language and mind Keynote speakers The following distinguished scholars will be giving keynote lectures relating to the conference themes: Lera Boroditsky, Stanford University Herbert H. Clark, Stanford University Adele Goldberg, Princeton University Sotaro Kita, Birmingham University George Lakoff, University of California, Berkeley Michael Tomasello, Max Planck Institute for Evolutionary Anthropology, Leipzig Theme Sessions In addition to a General Session and a Poster Session, there will be 6 specially-convened theme sessions, with specially invited discussants. These are as follows: 1. The socio-cultural, cognitive and neurological bases of metaphor Discussants: George Lakoff and Vyv Evans 2. Cognitive and social processes in language use Discussants: Herbert Clark and Paul Hopper 3. Constructional approaches to grammar and first language acquisition Discussants: Adele Goldberg and Eve Clark 4. The role of gesture in communication and cognition Discussants: Sotaro Kita and Alan Cienki 5. The social and cognitive bases of language evolution Discussants: Chris Sinha and Michael Tomasello 6. Linguistic relativity: Evidence and methods Discussants: Lera Boroditsky and Dan Slobin Submission of abstracts Submissions are solicited for the general session, the theme sessions, and the poster session. The abstract guidelines for all sessions are as follows: --Abstracts should not exceed 500 words - references are excluded from this count --Abstracts should clearly indicate a presentation title --Abstracts should be anonymous for purposes of blind peer-review --Abstracts should be formatted as Word, RTF or PDF documents --Abstracts should be submitted electronically to LCC@brighton.ac.uk Please include the following information in the main body of your email: --title and name of author(s) --affiliation --email address for correspondence --presentation title --3-5 keywords --preferred session for presentation: either general session, poster session, or theme session (please specify theme session number or title) Please include the following information in the subject header of your email: --"Abstract Submission - author(s) name(s)" *****************ABSTRACT DEADLINE: December 2nd 2007************************* For full details please consult the conference website: http://www.languageandcognition.net Organisers The conference is organised by Vyv Evans and St?phanie Pourcel Contact The conference email address is LCC@brighton.ac.uk Web details are available at: www.languageandcognition.net From gmsizemore2 from yahoo.com Tue Nov 27 07:52:41 2007 From: gmsizemore2 from yahoo.com (Glen M. Sizemore) Date: Wed Nov 28 14:33:36 2007 Subject: [Neuroscience] Re: Cannabis and the Brain: A User's Guide References: <474a76e2$0$19777$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <58d35f79-b9da-484b-8325-40dbf63b7491@b40g2000prf.googlegroups.com> Message-ID: <474c138a$0$20643$ed362ca5@nr2.newsreader.com> "John H." wrote in message news:58d35f79-b9da-484b-8325-40dbf63b7491@b40g2000prf.googlegroups.com... > Hey Peter, > > I used to reject the cannabis-psychosis link but the data on that > seems to firm up. Hi John, It is worth asking yourself, when you look at data like these, how big the effect really is. Remember, as N gets larger, the size of the effect that is detectable gets smaller and smaller. So, what is often praised (large N) probably needs to be rethought, though this is very unlikely to happen anytime soon (though there seems to be growing insistence on within-subjects comparisons where possible, though the reliance is still on statistical inference). Also remember, if one person out of 100,000 becomes psychotic normally, and among pot smokers it is three out of 100,000, the newspaper headlines will read "SMOKING POT TRIPLES RISK OF PSYCHOSIS!" Obviously, while true, your chance of becoming psychotic is very small. You probably know all this stuff (and you do point out, below, that the risk is low) but it doesn't hurt to be reminded, and I can't help but take every opportunity to denigrate null-hypothesis statistical testing. And, incidentally, this does not mean that one cannot do between-groups experiments. In the lab where I was trained, between-group experiments were nonexistent. Later, they started asking questions that could only be investigated using between-groups experiments. They might have six subjects in each group; if you get five in one group that shows an effect and, say, one in the other, you start to think you are on to something, though six and zero is better. Needless to say, an ANOVA would show this to be "highly significant," but at that point who gives a shit? On the other hand, if you have 25 subjects in each group and obtain a significant p-value, the "effect" could be quite trivial, even if replicated. >Moreover I've known a few people who have had > sufficiently severe psychotic episodes that they have sworn off the > weed forever. Another toke and they just sit in a corner losing their > religion. This does relate to heavy and sustained use, and the risk > is still rather low. Work and associated stress, living in or working > in CBDs(pollution), does more health damage than pot ever could. In my > view a good puff once a week is a very good way to ward off dementias. > The evidence on this is much stronger than the cannabis-psychosis link > but of course you won't see that evidence plastered over the front > pages. Gotta keep those peasants working. As Andrew Schmookler wrote, > "A man at peace with the world is an instrument of limited utility but > frustrate him enough and you can bend him to society's ends." (Parable > of the Tribes). Marvin Harris' explanation of the witch hunts in Europe relied heavily on this notion. Better to be standoffish with respect to others with whom you might otherwise bond and join together to exert "countercontrol"; after all, instead of bonding they might become pissed at you and tell the authorities you are a witch. > > I don't smoke that much now, in the past I didn't mind because, just > to contradict myself, I actually worked quite well while stoned. Too > old now, I just wanna sit back and relax but that gets too boring. > With discipline thinking on difficult problems while stoned can be > productive. I have heard this, though, of course, I have never smoked the evil weed! From j_hasenkam from yahoo.com.au Tue Nov 27 19:29:50 2007 From: j_hasenkam from yahoo.com.au (John H.) Date: Wed Nov 28 14:33:43 2007 Subject: [Neuroscience] Re: Cannabis and the Brain: A User's Guide References: <474a76e2$0$19777$5a62ac22@per-qv1-newsreader-01.iinet.net.au> <58d35f79-b9da-484b-8325-40dbf63b7491@b40g2000prf.googlegroups.com> <474c138a$0$20643$ed362ca5@nr2.newsreader.com> Message-ID: <374b1e87-e17a-4145-878b-26fca32abf70@s8g2000prg.googlegroups.com> On Nov 27, 10:52 pm, "Glen M. Sizemore" wrote: Hey Glen, I appreciate your thoughts re stats because I am weak in that area. I sometimes think there is too much "statistical fundamentalism" in bioscience. As Steve Jones the geneticist once wrote: "There are two kinds of scientists: those who use mathematics and those who understand mathematics." I understand what you are getting at and agree that the risk is over blown re pot and psychosis. What is happening in Australia though is that teenagers are taking up the weed and I do think there is a more significant risk regarding heavy pot use during the teenage years. (Perspective: Ritalin has a much worse safety profile.) However the latest stats now show that people in their 20's are shying away from pot, they seem to prefer the more moderate use of ecstasy and amphetamines, typically after a hard week's work they like to play hard on the weekends. No-one really understand the changes in drug consumption. The irony is that if the stats are to be believed then the current batch of teenagers face a far greater risk from brain tumours because of those bloody mobile phones. Again though, from a very low base. The sad thing is that exogenous cannabinoids have been ignored as a therapeutic alternative but show great promise in relation to dementias, brain injury, various cancers, atherosclerosis, inflammatory disorders, neuropathic pain and possibly even epilepsy. No need to get stoned, the principle benefit is arising predominantly from CB2 receptors, mostly on microglia and immune cells, and cannabidiol, which has bugger all if any affinity for the psychoactive CB1, is as good as THC. So here we have an extremely promising, very safe, non-psychoactive substance being ignored because of guilt by association. It's like hanging out with a behaviorist at a psychology conference. Be well, John. > "John H." wrote in message > > news:58d35f79-b9da-484b-8325-40dbf63b7491@b40g2000prf.googlegroups.com... > > > Hey Peter, > > > I used to reject the cannabis-psychosis link but the data on that > > seems to firm up. > > Hi John, > It is worth asking yourself, when you look at data like these, how big the > effect really is. Remember, as N gets larger, the size of the effect that is > detectable gets smaller and smaller. So, what is often praised (large N) > probably needs to be rethought, though this is very unlikely to happen > anytime soon (though there seems to be growing insistence on within-subjects > comparisons where possible, though the reliance is still on statistical > inference). Also remember, if one person out of 100,000 becomes psychotic > normally, and among pot smokers it is three out of 100,000, the newspaper > headlines will read "SMOKING POT TRIPLES RISK OF PSYCHOSIS!" Obviously, > while true, your chance of becoming psychotic is very small. You probably > know all this stuff (and you do point out, below, that the risk is low) but > it doesn't hurt to be reminded, and I can't help but take every opportunity > to denigrate null-hypothesis statistical testing. And, incidentally, this > does not mean that one cannot do between-groups experiments. In the lab > where I was trained, between-group experiments were nonexistent. Later, they > started asking questions that could only be investigated using > between-groups experiments. They might have six subjects in each group; if > you get five in one group that shows an effect and, say, one in the other, > you start to think you are on to something, though six and zero is better. > Needless to say, an ANOVA would show this to be "highly significant," but at > that point who gives a shit? On the other hand, if you have 25 subjects in > each group and obtain a significant p-value, the "effect" could be quite > trivial, even if replicated. > > >Moreover I've known a few people who have had > > sufficiently severe psychotic episodes that they have sworn off the > > weed forever. Another toke and they just sit in a corner losing their > > religion. This does relate to heavy and sustained use, and the risk > > is still rather low. Work and associated stress, living in or working > > in CBDs(pollution), does more health damage than pot ever could. In my > > view a good puff once a week is a very good way to ward off dementias. > > The evidence on this is much stronger than the cannabis-psychosis link > > but of course you won't see that evidence plastered over the front > > pages. Gotta keep those peasants working. As Andrew Schmookler wrote, > > "A man at peace with the world is an instrument of limited utility but > > frustrate him enough and you can bend him to society's ends." (Parable > > of the Tribes). > > Marvin Harris' explanation of the witch hunts in Europe relied heavily on > this notion. Better to be standoffish with respect to others with whom you > might otherwise bond and join together to exert "countercontrol"; after all, > instead of bonding they might become pissed at you and tell the authorities > you are a witch. > > > > > I don't smoke that much now, in the past I didn't mind because, just > > to contradict myself, I actually worked quite well while stoned. Too > > old now, I just wanna sit back and relax but that gets too boring. > > With discipline thinking on difficult problems while stoned can be > > productive. > > I have heard this, though, of course, I have never smoked the evil weed! > > From connelly.bill from gmail.com Wed Nov 28 16:37:18 2007 From: connelly.bill from gmail.com (Bill) Date: Wed Nov 28 17:00:00 2007 Subject: [Neuroscience] Excessive DC drift during field potential recording Message-ID: <758074ce-a270-4502-817a-14f0082b2aec@e10g2000prf.googlegroups.com> Hi, We're trying to record cortical spreading depression in rat brain slices, you microinject some 26mM KCl solution and it induces a 5-20mV spreading wave of depolarization across the cortex. The problem is we're getting really bad DC drift, the potential drifts up and down, sometimes by as much as +/-10mV. Turning ON the temperature controller makes it worse (presumably because of temperature swings). The hight of the tissue bath doesn't seem to be changing. Any ideas on what could be causing the drift, and hence how to get rid of it? (Oh, and I can't just AC couple the data, the spreading depression waves are 10+s long). From jalegris from sympatico.ca Fri Nov 30 09:05:47 2007 From: jalegris from sympatico.ca (J.A.Legris) Date: Fri Nov 30 09:58:57 2007 Subject: [Neuroscience] Re: Excessive DC drift during field potential recording References: <758074ce-a270-4502-817a-14f0082b2aec@e10g2000prf.googlegroups.com> Message-ID: <083e43a3-8960-4553-9ebe-4a4cf57ad22e@s8g2000prg.googlegroups.com> On Nov 28, 4:37 pm, Bill wrote: > Hi, > > We're trying to record cortical spreading depression in rat brain > slices, you microinject some 26mM KCl solution and it induces a 5-20mV > spreading wave of depolarization across the cortex. > > The problem is we're getting really bad DC drift, the potential drifts > up and down, sometimes by as much as +/-10mV. Turning ON the > temperature controller makes it worse (presumably because of > temperature swings). The hight of the tissue bath doesn't seem to be > changing. > > Any ideas on what could be causing the drift, and hence how to get rid > of it? > > (Oh, and I can't just AC couple the data, the spreading depression > waves are 10+s long). Can you post a link to circuit diagram of your setup? -- Joe From r_s_norman from _comcast.net Fri Nov 30 09:42:16 2007 From: r_s_norman from _comcast.net (r norman) Date: Fri Nov 30 09:59:01 2007 Subject: [Neuroscience] Re: Excessive DC drift during field potential recording References: <758074ce-a270-4502-817a-14f0082b2aec@e10g2000prf.googlegroups.com> <083e43a3-8960-4553-9ebe-4a4cf57ad22e@s8g2000prg.googlegroups.com> Message-ID: On Fri, 30 Nov 2007 06:05:47 -0800 (PST), "J.A.Legris" wrote: >On Nov 28, 4:37 pm, Bill wrote: >> Hi, >> >> We're trying to record cortical spreading depression in rat brain >> slices, you microinject some 26mM KCl solution and it induces a 5-20mV >> spreading wave of depolarization across the cortex. >> >> The problem is we're getting really bad DC drift, the potential drifts >> up and down, sometimes by as much as +/-10mV. Turning ON the >> temperature controller makes it worse (presumably because of >> temperature swings). The hight of the tissue bath doesn't seem to be >> changing. >> >> Any ideas on what could be causing the drift, and hence how to get rid >> of it? >> >> (Oh, and I can't just AC couple the data, the spreading depression >> waves are 10+s long). > >Can you post a link to circuit diagram of your setup? The most important thing to check is whether you get drift if you leave out the brain slice. That is, with the same apparatus in the same arrangement with the same electrodes and stimulation, does it drift? It is a LOT easier to fix things if the biology is not involved! Of course, if the electrodes are not in situ, they will have a different impedance and that can change things so you have to keep that in mind. Drift is probably from the metal-liquid interface. Do you have good chlorided silver interfaces that are in themselves stable? Rechloriding them and storing them in pairs shorted together can help. Of course if the ground electrode is a chlorided silver in the bath that sees the change in K+, it will change its electrochemical potential so you have to make sure the ionic composition of whatever touches the metal is constant. I believe that silver chloride can also get poisoned with protein accumulation on the surface and that can also be a problem. Cleaning and keeping the wires isolated from the biological solutions with liquid junctions can help. Of course, there is drift in the electronics, but that was more likely in the olden days of tube equipment and is more easily detected. Are there room temperature changes that can be affecting things (including electronics)? Silver chloride is also light sensitive so the afternoon sun coming through the window changing to night (if you are that dedicated!) is conceptually a problem. Yes, I am grasping at straws, here, in an attempt to be thorough.