Figure 2

Developmental song exposure and social context do not affect cFOS expression in TH neurons in the LC or PAG. (A) Examples of co-localized expression of TH (green) and cFOS (red) in the locus coeruleus (LC) of a normally-reared bird that heard silence (left panel), UD song (middle panel; UD song) and female-directed song (FD; right panel). White arrows indicate examples of co-localized expression. (B) Percent of TH neurons that express cFOS in the periaqueductal gray (PAG) and LC. While there was significant song-evoked cFOS expression in TH neurons of the LC (relative to silence; see Results), there were not significant effects of either rearing condition or stimulus context for either the PAG or LC. Box-and-whisker plots are for normally-reared (yellow colors) and song-naïve (green colors) hearing UD (UD; lighter colors) or female-directed (FD; darker colors) songs. Each box spans the interquartile range, horizontal white lines indicate the median and whiskers show the minima and maxima. Levels of cFOS expression in TH neurons for silence controls are plotted as the mean (gray dashed line) +/− standard error (gray boxes). There were no significant effects of rearing condition, stimulus, or an interaction at p < 0.05.