Figure 8. Representative examples of neurons expressing LHRH primary transcript {LHRH heteronuclear (hn) RNA{ in the OVLT/MPOA of female rats following various treatments. Intact cycling rats were sacrificed at 15:00 in proestrus afternoon (control), 3 h after an intraperitoneal (i.p.) administration of the bacterial endotoxin lipopolysaccharide (LPS) or after at least 48 h of food deprivation (Fasting). The groups of rats "LPS and Fasting" were also killed at proestrus 15:00, whereas 35% of food-deprived rats failed to show normal cyclicity and displayed a perturbed cycle; i.e permanent diestrus-2-like vaginal profile. These animals (Perturbed cycle) were sacrificed in parallel to the other groups, but at diestrus-2 15:00, in which they were supposed to be in proestrus 15:00. These dark-field photomicrographs were taken from hybridized 30-mm sections with a rat LHRH intronic probe generously provided by Drs A. Gore and J. Robert (Mount Sinai Medical School, NY). (Taken from Nappi and Rivest, ref. 183.)