Figure 3. Parallel output populations in ventral CA1/subiculum.
(A) Schematic of experiment, three differently tagged CTXβ tracers were injected into prefrontal cortex (PFC), nucleus accumbens (NAc) and basal amygdala (BA). (B) Example injection sites in each region. Scale bar 1 mm. (C) Horizontal section of CA1/subiculum in ventral hippocampus (vH) showing interspersed but non-overlapping labelling. Scale bars 300 µm (left), 100 µm (right). (D) Proportion of neurons labelled with CTXβ injection in NAc (red), BA (green) or PFC (grey) co-labelled with CTXβ from a different region. Note that there is only a small proportion of dual labelled neurons. (E) Strategy for electrophysiology recordings – projection populations were fluorescently labelled with retrobead injections into downstream projection areas. (F) Examples of positive (+160 pA) and negative (–40 pA) current steps in fluorescently targeted neurons from each population. Scale bar = 30 mV, 100 ms. (G, H) No large differences in input/output curve, resting potential, input resistance or sag amplitude across the three populations.