Modeling the passive properties of nonpyramidal neurons in hippocampal area CA3

We have been studying the passive membrane properties of nonpyramidal neurons in the CA3 region of the hippocampal formation. Using a combination of current-clamp recording, three-dimensional reconstruction, and compartmental modeling we examined the passive somatic membrane response and dendritic voltage attenuation in identified nonpyramidal, and therefore presumed inhibitory, neurons. The input resistance (R-N) of compartmental models closely fit measured values for R-N in more than 50% of cells studied. Membrane charging in these models, however, did not fit experimentally measured values. Finally, analysis of voltage attenuation in our neuron models suggests that voltage signals significantly attenuate from most dendritic locations to the soma.