Fig. 4. Representative photomicrographs showing c-Fos induction in the brain regions that were activated by orexin or MCH injection in the BLA. (A) Experimental design for stereotaxic injection with orexin or MCH peptides in the BLA, and time point for tissue preparation (arrow). Orexin or MCH peptides were injected into the BLA as described in Fig. 3A. (B-G) Photomicrographs showing c-Fos expression in the NAc (B, C), PVN (D, E), and CeA (F, G) following the injection of orexin (Orx) or MCH in the BLA. These three regions were commonly activated by the injection of orexin and MCH in the BLA. Quantification levels of c-Fos relative to the control are presented (C, E, G). Scale bar, 200 µm. Data are presented as the mean±SEM. ^* and ^** denote differences from the control at p<0.05 and p<0.01, respectively (n=6-7 animals). aca, anterior commissure, anterior; NAc-C, nucleus accumbens, core; NAc-Sh, nucleus accumbens, shell; PVN paraventricular nucleus of the hypothalamus; CeA, central amygdala; BLA, basolateral amygdala.