Electrophysiology and burst-firing of rat subicular pyramidal neurons in vitro: a comparison with area CA1.

Intracellular recordings were made from subicular and CA1 neurons in slices of the ventral hippocampal and parahippocampal region of the rat. All of the subicular cells that were stained by intracellular injection of biocytin were pyramidal in form. Although most electrophysiological properties were similar in the two areas, in response to depolarising current injection, the majority of subicular cells displayed a distinctive pattern of burst-firing which was rarely seen in CA1 cells. Burst-firing was voltage sensitive but was not abolished by blocking excitatory synaptic transmission, suggesting that it is an intrinsic membrane property of subicular pyramidal cells.