Fig. 2
Optogenetic activation of male-typical mounting in both sexes. a The strategy to optogenetically activate the mPOA. b Electrophysiological recordings of ChR2-expressing neurons in freshly cut brain slices. N = 25 male cells and 23 female cells. c Calcium imaging of acute brain slices were performed under a two-photon microscope at different stimulation frequencies as representative images showing at the top. ΔF/F values were averaged cross cells and plotted at the bottom with the blue bars indicating laser stimulation and the line and the shading indicating the mean and the s.e.m., respectively. N = 358 male neurons and 292 female neurons. Scale bar, 50 μm. d Average percentage of neurons activated at each tested frequency. N = 6 brain sections for males and 4 for females. e Representative raster plots of behaviors (color coded) displayed by mCherry and ChR2 animals of either sex during a behavioral trial in which a hormonal primed ovariectomized female was given as the stimulus. Blue bars indicate periods of light stimulation. f–j Photostimulation elicited male-typical mounting behavior toward hormonal primed ovariectomized females. The percentage of animals that displayed mounting behavior during photostimulation (f), trial-by-trial occurrence (g), average distribution (h), the latency (i), and average duration (j) of optogenetically activated mounting behavior were plotted. N = 83 ChR2 and 11 mCherry for males, and 58 ChR2 and 15 mCherry for females. k Percentage of ChR2 animals that displayed light-induced mounting behavior at low power of stimulation and high power. N = 9 males and 11 females. l Occurrence and distribution of mounting behavior before (bef.), during (dur.), and after light stimulation in those ChR2 animals, which had been castrated for >3 weeks. N = 9 males and 6 females. m Spontaneous mounting behavior that occurred outside of photostimulation. N = 83 ChR2 and 11 mCherry for males, and 58 ChR2 and 15 mCherry for females. Fisher’s exact test in f, k, and m. Unpaired t test in i. Paired t test in l. *p < 0.05, **p < 0.01, ***p < 0.001
