In article <1165701310.527446.233760 At n67g2000cwd.googlegroups.com>,
"Marcin" <marcin.gierlicki At gmail.com> wrote:
> Hi,
>> I'm looking for informations about signals frequencies in brain
> depending on area of it. For example range of frequencies for area
> responsible for hearing or motor function. I need this information to
> my master thesis about recordin extracellular signals from neuronal
> cells.
> Can someone help ?
>> Kind of animal dosen't matter ;)
>> Thanks,
> Marcin
Maximum spike rate in neurons can be up to 2kHz - I believe there are
phase-locked responses in cochlear afferents about this fast.
In cortex, 500-1000 spikes per second is the upper limit. Almost never
see 2 action potentials close than 1ms apart, aside maybe from burst
firing in a basket cell.
In cortical extracellular recording, we typically use bandpass filtering
to include, say, 300Hz - 10kHz, and would generally sample at
10kHz-20kHz depending on specific requirements (and yes, we know about
Nyquist limits!). Including lower frequencies causes a lot of baseline
shifts in potential to interfere with spike discrimination. Sadly the
baseline shifts are probably very important to cortical function, we
just don't know how!
Cheers, MK.
