To investigate the relationship between the thermoregulatory system and the brain-reward system, we examined effects of heat exposure and tail amputation on lever-pressing behavior in intracranial self-stimulating rats. Rats that continuously pressed a lever voluntarily for 1 hour at an ambient temperature (Ta) of 22°C interrupted lever pressing and showed heat loss behaviors, such as grooming and body extension, at a Ta of 36°C. Hypothalamic temperature (Thy) at the time of the first body extension was higher than that after 1 hour of lever-pressing at a Ta of 22°C. Tail amputation experiments showed the same result. Thy at the onset of the body extension after tail amputation was higher than that at the end of 1 hour of lever-pressing under control conditions. The data suggest that thermal factors, especially Thy, are important in the control of lever-pressing behavior.
- Heat stress
- Intracranial self-stimulation
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience