Fig. 4

Correlation between optogenetically induced c-Fos expression and behaviors. a Example images of DAB staining of light-induced c-Fos expression in a ChR2 animal along the anterior–posterior axis at ~80 μm intervals. Scale bar, 200 μm. b Heat map representation of light-induced c-Fos expression averaged across animals. Briefly, c-Fos signals within each 100 μm² square in a 1100 × 1500 μm area as in a were counted, tallied, averaged, plotted, and projected onto a reference atlas (http://www.brain-map.org/, image 49–61). White bold lines highlight the mPOA defined by the atlas. Scale shown on the right. c Activation centers for ChR2 animals. N = 66 males and 53 females. d–f Correlation between total number of c-Fos signals in sections highlighted with the thick black line in c and the trial occurrence of light-induced locomotion (d), mount (e), and pup retrieval (f) for both male and female ChR2 animals. Pearson’s correlation. g Distribution of optogenetic-induced locomotion, mount, and pup retrieval (color coded) in ChR2 males (left) and females (right) with each column corresponding to a ChR2 animal and the shade of each cell corresponding to the trial occurrence of the behavior indicated on the left. The scale bar is on the right. Animals were sorted according to the occurrence of light-induced mounting behavior. Out of 35 males and 33 females that displayed light-induced mounting, 31 males and 31 females also displayed light-induced pup retrieval. Of 26 males and 22 females that did not display light-induced mounting, only 8 males and 10 females displayed light-induced pup retrieval. h Categorical comparison of the occurrence of light-induced locomotion, mount, and pup retrieval at the animal level between groups whose activation center lie within or close to the mPOA, as in sections highlighted with a black line in c (hit), and those away from the mPOA (miss). Filled segments indicate the fraction of animals in each group that displayed optogenetically induced behaviors listed below while corresponding empty segments indicate the fraction that did not display the behavior. Fisher’s exact test. *p < 0.05, **p = 0.01