Anapyrexia

A primary and pervasive question in my laboratory is geared toward understanding how and why animals lower body temperature in hypoxia. Ectotherms are extremely useful models to explore this question, since they regulate body temperature behaviourally. The body temperature of endotherms, on the other hand, is regulated physiologically. Changes in body temperature of endotherms could have a pathological (i.e. failure of thermogenesis) rather than regulatory (i.e. neural set-point) basis. Thus, by examining behavioural thermoregulation in ectotherms, we are able to make inferences about the body’s central thermostat.

 

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A wide array of animals purposely choose to reduce body temperature in hypoxia.  Because this has been shown to be effected via behavioural thermoregulation, it is referred to by many as “anapyrexia”.  Source: Wood (1995)

 

We are examining this question primarily in bearded dragons, though we have examined hypoxia-induced changes in thermoregulation in toads, frogs, squirrels, and fish.

 

Sources

Dzialowski, E, Tattersall, GJ, Nicol, SC, and Frappell, PB. 2014. Fluctuations in oxygen influence facultative endothermy in Bumblebees. Journal of Experimental Biology, 217: 3834-3842.

Tattersall, GJ and Milsom, WK. 2009. Hypoxia reduces metabolic thresholds and hypothalamic thermosensitivity. Journal of Physiology, 587: 5259-5274.

Cadena, V and Tattersall, GJ. 2009. Decreased thermoregulatory precision contributes to the hypoxic thermoregulatory response in lizards. Journal of Experimental Biology. 212: 137-144.

Tattersall, GJ and Barraza, J. 2008. The influence of hypoxia on the thermal control of skin colouration in the bearded dragon, Pogona vitticeps. Journal of Comparative Physiology B, 178: 867-875.

Rollinson, N, Tattersall, GJ, and Brooks, RJ. 2008. Winter temperature selection in relation to dissolved oxygen concentrations in a natural population of Painted Turtles (Chrysemys picta). Journal of Herpetology. 42: 312-341.

Tattersall, G. J. and Gerlach, R. M. 2005. Hypoxia progressively lowers thermal gaping thresholds in bearded dragons, Pogona vitticeps. Journal of Experimental Biology 208: 3321-3330.

Tattersall, G. J. and Milsom, W. K. 2003. Transient peripheral warming accompanies the hypoxic metabolic response in the golden-mantled ground squirrel. Journal of Experimental Biology 206: 33-42.

Tattersall, G. J. and Boutilier, R. G. 1999. Does behavioural hypothermia promote exercise recovery in cold-submerged frogs? Journal of Experimental Biology, 202: 609-622.

Tattersall, G. J. and Boutilier, R. G. 1997. Balancing hypoxia and hypothermia in cold-submerged frogs. Journal of Experimental Biology 200: 1031-1038.

 

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