Q: how to distinguish pre- or postsynaptic inhibition?
Richard.Vickery at unsw.edu.au
Tue Aug 8 20:47:48 EST 2000
Kung-Chiao Hsieh wrote:
> Just wandering how neurophysiologists can tell the inhibition occurs
> presynaptically or postsynaptically from the recording electrodes. Can
This depends upon your recording technique etc.
If you have access to the cell's interior (patch clamping or
sharp electrode) then a post-synaptic inhibition will show up as
an inhibitory potential (negative potential) whereas pre-synaptic
inhibition will not show up as a postsynaptic current. You may
have to test the cell at a series of holding potentials to see
Alternatively you can use pharmacology to help as postsynaptic
inhibiton is usually GABA-A mediated and blocked by bicuculline
whereas presynaptic inhib is usually GABA-B mediatedand blocked
There are plenty of other tricks, many more indirect but which
can lead to a reasonably safe conclusion.
Dr Richard Vickery
School of Physiology & Pharmacology, UNSW, Australia, 2052
ph. 61 2 93851676, fax 61 2 93851059
More information about the Neur-sci