This study systematically examined the distribution of growth hormone secretagogue receptor (GHSR) mRNA in the adult rat and mouse brains and cervical spinal cords using in situ hybridization histochemistry (ISHH) with novel cRNA probes specific for the mRNA encoding the functional GHSR (type 1a variant). The results confirmed GHSR mRNA expression in several hypothalamic nuclei, including the arcuate nucleus (Arc), ventromedial hypothalamic nucleus (VMH), and lateral mammillary nucleus, which are known to play roles in body weight and food intake. Additionally, GHSR was found in several other regions, including many parasympathetic preganglionic neurons and all three components of the dorsal vagal complex. The study also examined the co-expression of GHSR with tyrosine hydroxylase (TH) and cholecystokinin (CCK), revealing a high degree of GHSR mRNA expression within dopaminergic, CCK-containing neurons of the substantia nigra and ventral tegmental area. The findings highlight the widespread distribution of GHSR mRNA in the CNS and suggest potential roles for ghrelin in regulating complex behaviors and autonomic functions.This study systematically examined the distribution of growth hormone secretagogue receptor (GHSR) mRNA in the adult rat and mouse brains and cervical spinal cords using in situ hybridization histochemistry (ISHH) with novel cRNA probes specific for the mRNA encoding the functional GHSR (type 1a variant). The results confirmed GHSR mRNA expression in several hypothalamic nuclei, including the arcuate nucleus (Arc), ventromedial hypothalamic nucleus (VMH), and lateral mammillary nucleus, which are known to play roles in body weight and food intake. Additionally, GHSR was found in several other regions, including many parasympathetic preganglionic neurons and all three components of the dorsal vagal complex. The study also examined the co-expression of GHSR with tyrosine hydroxylase (TH) and cholecystokinin (CCK), revealing a high degree of GHSR mRNA expression within dopaminergic, CCK-containing neurons of the substantia nigra and ventral tegmental area. The findings highlight the widespread distribution of GHSR mRNA in the CNS and suggest potential roles for ghrelin in regulating complex behaviors and autonomic functions.