Altered responsivity to central administrations of corticotropin-releasing factor in rats with a history of opiate exposures.
The authors studied the effects of a history of opiate exposures on behavioral responses to intracerebroventricular (ICV) microinjections of the stress-related peptide corticotropin-releasing factor (CRF). Rats were injected for 10 days with morphine (10 mg/kg) or saline, and 1 or 7 days later they received an ICV microinjection of CRF (0.5 microg or 2.5 microg) or artificial cerebrospinal fluid. Microinjections of CRF produced anxiety-like behavior, locomotor activity, and self-grooming. The anxiogenic response was altered so that morphine-treated rats showed reduced responses to 0.5-microg CRF but showed exaggerated responses to 2.5-microg CRF 1 or 7 days after last opiate exposure. These findings suggest that alterations in central CRF circuits may underpin the increased vulnerability to anxiety observed following opiate exposures.
Blatchford
Kate E
KE
School of Psychology, University of New South Wales, Sydney, NSW, Australia.
Choi
Eun A
EA
McNally
Gavan P
GP
D000818:Animals; D001143:Arousal / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D006120:Grooming / Q000187:drug effects* / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D008845:Microinjections; D009021:Morphine Dependence / Q000503:physiopathology*; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009415:Nerve Net / Q000187:drug effects / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar
D003346:Corticotropin-Releasing Hormone