(A and B) Photomicrographs of Fos expression in the MnPO, 90 min after focal microinfusion of either vehicle (A, aCSF) or senktide (B). Note the marked increase in Fos-immunoreactive nuclei in senktide-microinfused rats. (C) Core temperature before and after vehicle or senktide microinfusion into the MnPO of ovariectomized, estradiol-treated rats (ambient temperature of 21.5 °C, mean ± SEM, n = 6–8 microinfusions/group). Senktide microinfusion into the MnPO markedly decreased core temperature. Scale bar in B = 100 microns and applies to A and B. aCSF, artificial cerebrospinal fluid, 3V, Third ventricle; ac, anterior commissure; MnPO, median preoptic nucleus. # Significantly different, senktide compared with vehicle. Modified with permission from Dacks et al. (2011a).