Genetic selection alters thermoregulatory response to ethanol

Area of Science:

• Neuroscience
• Pharmacology
• Animal Behavior

Background:

• Ethanol (alcohol) affects body temperature regulation.
• Selecting mice for differing responses to ethanol can reveal genetic influences on thermoregulation.
• Understanding ethanol's hypothermic effects is crucial for managing alcohol intoxication.

Purpose of the Study:

• To investigate the impact of ethanol on thermoregulation in mice selectively bred for distinct body temperature responses.
• To determine if central nervous system (CNS) regulation of body temperature differs between ethanol-sensitive and ethanol-resistant mouse lines.

Main Methods:

• Two lines of mice (HOT and COLD) were selectively bred for smaller or larger rectal temperature declines after ethanol administration.
• Mice were implanted with telemetry devices for continuous internal temperature monitoring.
• Animals were trained in a temperature gradient to assess behavioral thermoregulation in response to saline or ethanol injections.

Main Results:

• Both HOT and COLD mice exhibited a regulated decline in body temperature following ethanol administration.
• COLD mice demonstrated greater sensitivity to ethanol's hypothermic effects compared to HOT mice.
• Behavioral selection of cooler temperatures in the gradient correlated with falling internal body temperatures, indicating active thermoregulatory adjustments.

Conclusions:

• Selective breeding effectively created mouse lines with differing sensitivities to ethanol-induced hypothermia.
• These findings suggest a genetic basis for differences in the CNS regulation of body temperature in response to ethanol.
• The study provides a valuable model for exploring the neurobiological mechanisms underlying ethanol's effects on thermoregulation.