Table 3. Properties of EPSPs Elicited by Pyramidal Cells in the Two Types of SP Dendrite-Preferring Interneurones in the CA2 Region
Cell type
MP (mV)
Mean amplitude(mV)
EPSP half width (ms)
EPSP 10–90% rise time (ms)
1st EPSP CV
% Failures 1st EPSP
PPR 10–20 ms
PPR 20–40 ms
The asterisks stand for values that are statistically significant. Data are represented as mean ± standard deviation (SD). M, mean amplitude; MP, membrane potential; CV, coefficient of variation; PPR, paired pulse ratio. EPSPs elicited in SP–SR interneurones were similar in amplitude to those elicited in CA1 and CA2 bistratified cells (MW U, P > 0.05). The width at half amplitude of these EPSPs was, however, significantly broader than those of EPSPs elicited in CA1 bistratified cells (MW U, P < 0.05, U = 0) and in narrow dendritic arbor CA2 bistratified cells (MW U, P < 0.05) but similar to those elicited in CA2 wide dendritic arbor bistratified cells (MW U, P > 0.05). The 10–90% rise time was not, however, significantly different from that of EPSPs elicited in CA1 bistratified cells or narrow and wide dendritic arbor CA2 bistratified cells (MW U, P > 0.05). The proportion of apparent failures of synaptic transmission was larger for EPSPs elicited in CA2 SP–SR interneurones and in CA2 wide dendritic arbor bistratified cells than that for those elicited CA2 narrow arbor bistratified cells and CA1 bistratified cells.
