Investigating the hedonic effects of interferon-alpha on female rats using brain-stimulation reward.
Interferon-alpha (IFN-alpha) is used as a front-line treatment for cancer and other diseases. Reports of depression as a consequence of IFN-alpha therapy scatter the literature, generating interest in the CNS disruptions elicited by this cytokine. In the present work, we investigated the short- and long-term effects of a single systemic injection of vehicle, 10, or 1000 units of IFN-alpha on temperature, body weight, food intake, sickness behaviours, locomotor activity, and brain stimulation reward (BSR) thresholds elicited from the ventral tegmental area in female Long-Evans rats. Pioneered for studying motivational processes, BSR has been exploited as a tool for tracking hedonic status in animal models of depression. In this study, the main findings were that IFN-alpha did not induce anhedonia as defined by no increase in frequency thresholds. However, the analyses of sickness behaviours unveiled a significant increase in piloerection in all sham control animals that received an IFN-alpha injection while the BSR animal scores remained relatively unchanged between pre- and post-injection days. This pattern was also evident in the overall total sickness behaviour scores. Our data suggest that a single exposure to IFN-alpha treatment in female rats elicits long-term somatic effects, without altering hedonic status.
Kentner
Amanda C
AC
School of Psychology, University of Ottawa, Ottawa, Canada K1N 6N5.
James
Jonathan S
JS
Miguelez
Maïa
M
Bielajew
Catherine
C
D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D007155:Immunologic Factors / Q000494:pharmacology*; D016898:Interferon-alpha / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D012653:Self Stimulation
D007155:Immunologic Factors; D016898:Interferon-alpha