>> This may seem like a very simply question, but I've heard two different
> electrophysiologists (both of whom publish in fancy journals as a
> matter of course) give two different explanations as to why field
> potentials of action potentials recorded from a cell body region (e.g.
> Stratum Pyramidale of CA1) are positive, while field potentials caused
> by dendritic excitation (e.g. Stratum Radiatum of CA1) are negative.
>> What is your understanding of this?
Correction: Why is the field potential in stratum pyramidale that is
NOT the action potential, i.e. the EPSP, positive, while the EPSP
recorded in the dentrites negative?