Kavaliers, M. & Colwell, D. D. 1996: Synergism between stress responses induced by biting flies and predator odours. Ethology 102, 89–98.
Synergism Between Stress Responses Induced by Biting Flies and Predator Odours
Article first published online: 26 APR 2010
1996 Blackwell Verlag GmbH
Volume 102, Issue 1, pages 89–98, January-December 1996
How to Cite
Kavaliers, M. and Colwell, D. D. (1996), Synergism Between Stress Responses Induced by Biting Flies and Predator Odours. Ethology, 102: 89–98. doi: 10.1111/j.1439-0310.1996.tb01106.x
- Issue published online: 26 APR 2010
- Article first published online: 26 APR 2010
- Received March 28, 1995; Accepted August 1, 1995 (J. Brockmann)
We have previously shown that endogenous opioid systems (i.e. endorphins, enkephalins) are involved in the mediation of the behavioural and physiological effects of biting-fly exposure. Opioid mediated reductions in pain sensitivity, or, more appropriately, nociceptive sensitivity (latency of a foot-lifting response to a 50°C thermal surface), are evident in laboratory mice, Mus musculus domesticus, exposed to biting flies. Similar opioid-mediated reductions in pain sensitivity (opioid analgesia) are also seen after exposure to a variety of other natural stressors such as the threat of predation. Here, we demonstrate that brief (30-min) exposure of male mice to stable flies, Stomoxys calcitrans, significantly and synergistically augments either the concurrent or subsequent (60 min after fly exposure) analgesic effects induced by exposure to a predator (cat odour). These results demonstrate that the analgesic, and probably other opioid mediated behavioural and physiological stress responses induced by exposure to a relatively low number of biting flies, are markedly increased by the presence of another natural aversive stimulus. In addition, they show that biting-fly exposure significantly exacerbates the effects of a subsequent stressful stimulus. These findings raise a possible mechanism whereby exposure to a low number of biting flies, which by themselves may not appear to have a great impact, can have marked behavioural and physiological consequences.