Fig. 6
From: A hippocampal circuit linking dorsal CA2 to ventral CA1 critical for social memory dynamics
dCA2 provides excitatory input to vCA1a PNs. a Diagram of patch-clamp recordings from vCA1 PNs in response to photostimulation of ChR2-eYFP-expressing fibers from dCA2 PNs. Typical recording site in vCA1a. b Post hoc immunohistochemistry after patch-clamp recording from a vCA1a PN showing the recorded cell (filled with biocytin, red) and ChR2-eYFP-labeled dCA2 fibers (green). c Photostimulation (1 ms blue light pulse) of dCA2 inputs with increasing strengths of illumination evoked PSPs of increasing amplitude in a vCA1a PN. Highest intensity light pulse elicited an action potential. d Peak PSP depolarization from deep and superficial vCA1 PNs and from deep dCA1 PNs in response to photostimulation of dCA2 inputs at maximum light intensity (light intensity before action potentials were triggered or beyond which no further increase in PSP amplitude was observed). No difference was found between deep and superficial vCA1 PNs PSPs (ndeep vCA1a = 11 cells, 6 mice; nsuperficial CA1a = 11 cells, 7 mice; unpaired t test: t(20) = 0.6334, P = 0.5337). Deep dCA1 PNs PSPs (n = 14 cells, 7 mice) were ~twofold larger in amplitude than those in vCA1 (deep and superficial combined; unpaired t test: t(34) = 2.540, P = 0.0158). Results show mean ± s.e.m. *P < 0.05. Circles represent individual cells. Scale bar, 250 µm (b)