In article <1le311INNbjg at shelley.u.washington.edu> venk at stein.u.washington.edu (Venkatesh Murthy) writes:
>The EPSP is usually due to synaptic currents flowing INTO the dendrites - in
>other words, the sink is more distal to the soma (and your recording
>electrode in the cell body layer. So at the location you are recording
is in the cell body layer).
>from there is in effect a source. When the population spike occurs,
>presumably many of the cells are spiking. This causes a great big sink
>to occur near/at the some since by far most of the action potential
>currents are dominant at the soma (if not by density of channels, by
>sheer number). So, your recording electrode is seeing a sink and it
>records a "negative" potential.
>>Can someone else confirm or refute this? Bill Calvin, maybe?
Sorry for the typos!
Physiology & Biophysics, SJ-40
University of Washington
Seattle, WA 98195
(venk at u.washington.edu)