Prolactin-induced pSTAT5 in the female rat forebrain. A–L: Representative images showing pSTAT5 immunohistochemistry in the rostral preoptic area (A–D), paraventricular nucleus (E–H), and arcuate nucleus (I–L) in response to vehicle (A,E,I), 10 ng (B,F,J), 500 ng (C,G,K), or 5 μg icv prolactin doses (D,H,L). M–O: Graphs summarizing the mean number of pSTAT5-labeled nuclei per brain section in response to 10 ng (n = 7), 500 ng (n = 7), or 5 μg (n = 6) prolactin icv, or vehicle (n = 6) in each area. Bars with different letters are significantly different compared with vehicle (P < 0.05). Scale bars = 100 μm in A–L.