IUBio

[Neuroscience] Re: A hypothesis (Re: Can a single neuron release multiple neurotransmitters?)

John H. via neur-sci%40net.bio.net (by j_hasenkam At yahoo.com.au)
Wed Jan 3 09:00:20 EST 2007


Very vaguely Peter, my memory on this is not clear, but I think there
were some news reports a few years indicating that neurons can "switch
careers"; though this was only during embryonic development. so I
looked

Extract

Other examples of two fast neurotransmitters released from the same
neuron include GABA and glycine in interneurons of the spinal cord (5)
and glutamate and dopamine in ventral midbrain dopamine neurons (6). Of
all CNS neurons, the granule cells of the dentate gyrus appear to be
the champions of neurotransmitter colocalization: glutamate,
enkephalin, dynorphin, zinc, and finally GABA (2)(

---

Trick was to search for "single neuron" AND neurotransmitter. Stop
making me  think dude, it's been a long day and I'm tired.


Shall we sing a lament for the poms?. They are not taking those Ashes
back dude. I'll brain the bastards if they do!!!


Be well,


John.



Epilepsy Curr. 2002 Sep;2(5):143-145. Related Articles, Links


The GAD-given Right of Dentate Gyrus Granule Cells to Become GABAergic.

Mody I.

Departments of Neurology and Physiology, The David Geffen School of
Medicine, UCLA, Los Angeles, California.

JANUS, THE ANCIENT ROMAN GOD OF GATES AND DOORS HAD TWO FACES: one
looked into the past, and the other, into the future. Do neurons
possess a Janus face when it comes to neurotransmitters, or a given
neuron is to be forever solely gamma-aminobutyric acid (GABA) ergic,
glutamatergic, dopaminergic, peptidergic, or
YOURPREFERREDTRANSMITTERergic? The answer is that the terminals of many
neurons are homes to even more than two neurotransmitters. All this in
spite of the "one neuron-one transmitter" usual misinterpretation of
Sir Henry Hallett Dale's postulate, originally meant to indicate that a
metabolic process taking place in the cell body can influence all
processes of the same neuron. A large variety of neurons in the CNS,
many of them GABAergic, produce and release chemicals that satisfy some
of the criteria used to define neurotransmitters. The usual scenario
for a dual-transmitter terminal is that the fast-acting transmitter
such as GABA or glutamate is stored in regular synaptic vesicles,
whereas a neuropeptide is stored in dense core vesicles (1). The
vesicular zinc found in many glutamatergic terminals also may be
considered to be a second neurotransmitter, based on its vesicular
packaging with the aid of a specific vesicular transporter, and its
postsynaptic actions through high-affinity binding sites and permeation
through certain channels (2). Whenever a "fast" and a "slow"
neurotransmitter are present in the same presynaptic terminal, it is
customary to assume that their release can be differentially regulated
(1). There is little convincing experimental support for this
phenomenon in the mammalian CNS. The coexistence of two "fast"
neurotransmitters in the same terminal is less frequent, but not
unheard of. In neonatal sympathetic neurons cocultured with cardiac
myocytes, norepinephrine and acetylcholine coexist and have opposite
actions on the cardiac muscle cells (3). Very recently we learned that
brain-derived neurotrophic factor acting at the low-affinity
neurotrophin receptor p75(NTR), perhaps as part of a programmed
developmental switch, can convert the phenotype of the sympathetic
neuron from noradrenergic to cholinergic (4). Other examples of two
fast neurotransmitters released from the same neuron include GABA and
glycine in interneurons of the spinal cord (5) and glutamate and
dopamine in ventral midbrain dopamine neurons (6). Of all CNS neurons,
the granule cells of the dentate gyrus appear to be the champions of
neurotransmitter colocalization: glutamate, enkephalin, dynorphin,
zinc, and finally GABA (2)(7)(8)(9). With this many transmitters in a
single neuron, there are probably different ways in which they can be
released. Dynorphin and other opioid peptides can be released directly
from the dendrites to inhibit excitatory transmission (8). A similar
mechanism may take place for GABA, as described in cortical GABAergic
neurons (10).

PMID: 15309121 [PubMed - as supplied by publisher]

Entertained by my own EIMC wrote:
> I *hypothesize* (or speculate) the existence (or is it already known?) of
> neurons that release one type of transmitter when firing for a relatively
> short time but a different transmitter after a while when firing
> persistently for a relatively long time (or perhaps that after a while of
> persistent firing release 'the last' transmitter at a higher ration to 'the
> first').
> 
> Please confirm or debunk as appropriate!
> 
> P



More information about the Neur-sci mailing list

Send comments to us at biosci-help [At] net.bio.net