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?