Genetic selection alters thermoregulatory response to ethanol

The present study examined the effect of ethanol on the regulated temperature of two lines of mice selected in replicate for a smaller (HOT1 and HOT2) or greater (COLD1 and COLD2) decline in rectal temperature after IP ethanol. Mice were implanted with indwelling telemetry devices for remote monitoring of internal temperature and trained in a temperature gradient (8-40°C). Both internal and selected temperature were tracked and recorded with a computer after injections of NaCl or various doses of ethanol. All animals responded similarly to control injections, with a transient rise in body temperature. After an effective dose of ethanol, mice showed clear evidence of a regulated decline in body temperature, as evidenced by selection of low temperatures in the gradient at the same time internal temperatures were falling. COLD mice were more sensitive than HOT mice; this was apparent in both replicates of the selected lines, indicating that a difference in the CNS regulator of body temperature has been selected for in these animals.