The Effects of Orexin A and B on Two Forms of Immobility Responses and on Analgesia

摘要: The orexins are important for the regulation of several behavioral patterns, including feeding, arousal state, drug seeking, voluntary locomotion and nociception. Two (A B), two different orexin receptors known, which have differential distribution. This suggests that distinct may regulate specific behaviors such as immobility associated analgesia. periaqueductal gray (PAG) is considered to be main center analgesia responses in central nervous system (CNS). Here we compared effect A (OX-A) B (OX-B) after intracerebroventricular (ICV) or ventrolateral (vl-PAG) injection. forms were studied: cataleptic (CAT) tonic (TI) responses. latter was with part a defensive response species. We observed OX-A more effective than OX-B reduce CAT; slightly potent decrease TI neither able induce when injected ICV. After microinjection into vl-PAG CAT unaffected by both significantly TI. Microinjected did not show analgesic activity but produced significant assessed tail-flick test.