Title: Feeding and activity induced by orexin A in the lateral hypothalamus in rats
Abstract: Orexin A injected into the lateral hypothalamus (LH) stimulates feeding and activates neurons in brain sites regulating feeding and arousal. The feeding effects of orexin A have been demonstrated during the light cycle, a time when rats are normally resting, and the effect of orexin A on activity after injection into the LH has not been previously measured. Thus, it is unclear whether LH orexin A-induced feeding is secondary to enhanced arousal. To address this, LH-cannulated rats habituated to a running wheel were injected with either orexin A (1000 pmol) or vehicle during light and dark cycles. Food intake and running wheel rotations were measured for 2 h. Spontaneous physical activity (SPA) was also measured during the dark cycle. During the light cycle, orexin A in the LH stimulated feeding in the presence and absence of a running wheel and increased number of running wheel rotations in the presence and absence of food. During the dark cycle, orexin A in the LH induced SPA (±presence of food), but had no effect on feeding. These data show that LH orexin A stimulation of feeding is not always coincident with increased activity, suggesting that feeding induced by LH-injected orexin A is not consequent to enhanced arousal.
Publication Year: 2002
Publication Date: 2002-03-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 163
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