Figure 7.

Characterization of dentate gyrus non-granule cells. (A) Intrinsic electrophysiology of DG non-granule cells include two classes primarily, those cells that are regular-spiking and those that are not. Regular-spiking cells are mossy cells with hilar cell bodies and an axon in all layers but the outer and middle molecular layers. Fast-spiking cells are found in all layers and have axons that are in all layers. (B) Axon location indicates at least six types of non-granule cells. GABAergic neurons include basket cells, typically with a pyramidal cell-shaped soma, axo-axonic cells, HIPP cells, HICAP cells, and MOPP cells (Han et al., 1993; Freund and Buzsáki, 1996). Recent studies suggest that neurogliaform cells and ivy cells exist (Armstrong et al., 2011, 2012). (C) Mossy cells can be divided into two categories based on the location of their dendrites, cell body, and threshold to stimulation of the perforant path. Cells with dendrites in the molecular layer and primarily located near the cell layer have low thresholds for activation by the perforant path.