Fig. 2.

Optically-evoked currents in CRF + neurons of PVN and GAD + neurons of the BNST.

a) ChR and EYFP were expressed in CA1 pyramidal cells of the ventral hippocampus/subiculum in CRF-tdTomato reporter mice (male and female). b) Whole-cell voltage-clamp recordings from a CRF + neurons in the PVN. Photostimulation in the fornix elicited oEPSCs and oIPSCs at holding potentials of −60mV and 0 mV, respectively. Sample traces obtained with 10 stimuli delivered 1 min apart. Optical stimulation delivered at time indicated by blue bar and the latency to oIPSC (0 mV) and oEPSC (−60 mV) onset shown with orange bar. c) Pairwise comparison of oEPSCs and oIPSCs in single cells (n = 3) demonstrated an increased stimulus-response latency for oIPSCs compared to oEPSCs (p = 0.0162), but not significant differences in oEPSC and oIPSC amplitude or conductance. There was a large difference in jitter between oEPSCs and oIPSCs that did not reach statistical significance (p = 0.08). d) Number of cells in which oEPSCs, oIPSCs, or both were elicited. e) ChR and EYFP were expressed in CA1 pyramidal cells in GAD-tdTomato mice. f) Whole-cell voltage-clamp recordings from a GAD + inhibitory neuron in the BNST. Photostimulation in the fornix elicited oEPSCs and oIPSCs at holding potentials of −60mV and 0 mV, respectively. Optical stimulation delivered at time indicated by blue bar and the latency to oIPSC (0 mV) and oEPSC (−60 mV) onset shown with orange bar. g) There was an increased stimulus-response latency for oIPSCs compared to oEPSCs (n = 6, p = 0.0074), but no significant differences in oEPSC and oIPSC amplitude (n = 6, p = 0.3351) or conductance (n = 6, p = 0.1792). h) All six BNST cells recorded demonstrated both oEPSCs and oIPSCs. *, p < 0.05; **, p < 0.01. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)