Effect of localized changes in scrotal and trunk skin temperature on the demand for radiant heat by pigs.
Localized warming of the scrotal skin to 42 degrees C decreased the number of operant responses for reinforcements of radiant heat when young pigs were exposed to cold (15 degrees C); warming a similar area of the skin on the trunk had no effect on behaviour. The decrease in responding for heat was more pronounced immediately after a meal than when animals were observed 22 hr after their last meal. Cooling the scrotal or trunk skin to 20 degrees C did not modify operant behaviour. It is concluded that the thermal signal from the scrotum is in disproportion to the surface area of the scrotum indicating either increased concentration of thermal receptors per surface unit of the skin, or processing and amplifying the thermal information along the scrotal-brain neural pathway. The significance of the elicited changes in the demand for radiant heat is discussed in relation to the control of testes temperature.
D000818:Animals; D001833:Body Temperature Regulation; D003216:Conditioning, Operant / Q000502:physiology; D008297:Male; D012611:Scrotum / Q000294:innervation*; D012881:Skin Temperature; D013552:Swine; D013823:Thermoreceptors / Q000502:physiology*