Central amygdalar nucleus treated with orexin neuropeptides evoke differing feeding and grooming responses in the hamster.
Interaction of the orexinergic (ORXergic) neuronal system with the excitatory (glutamate, l-Glu) or the inhibitory (GABA) neurosignaling complexes evokes major homeostatic physiological events. In this study, effects of the two ORXergic neuropeptides (ORX-A/B) on their receptor (ORX-2R) expression changes were correlated to feeding and grooming actions of the hibernating hamster (Mesocricetus auratus). Infusion of the central amygdala nucleus (CeA) with ORX-A caused hamsters to consume notable quantities of food, while ORX-B accounted for a moderate increase. Interestingly the latter neuropeptide was responsible for greater frequencies of grooming with respect to both controls and the hamsters treated with ORX-A. These distinct behavioral changes turned out to be even greater in the presence of l-Glu agonist (NMDA) while the α1 GABAA receptor agonist (zolpidem, Zol) greatly reduced ORX-A-dependent feeding bouts. Moreover, ORX-A+NMDA mainly promoted greater ORX-2R expression levels with respect to ORX-A-treated hamsters while ORX-B+Zol was instead largely responsible for a down-regulatory trend. Overall, these features point to CeA ORX-2R sites as key sensory limbic elements capable of regulating eating and grooming responses, which may provide useful insights regarding the type of molecular mechanism(s) operating during feeding bouts.
['Alò|Raffaella|R|', 'Avolio|Ennio|E|', 'Mele|Maria|M|', 'Di Vito|Anna|A|', 'Canonaco|Marcello|M|']
D000818:Animals D066274:Central Amygdaloid Nucleus D006224:Cricetinae D005247:Feeding Behavior D058785:GABA-A Receptor Agonists D006120:Grooming D008297:Male D008647:Mesocricetus D016202:N-Methylaspartate D064446:Orexin Receptors D000068797:Orexins
Orexin Amygdala NMDA Feeding behaviors GABA(A) receptor