Rats cope with the cold just like humans

WASHINGTON - When winter arrives, Australian bush rats behave much the same as their larger, human counterparts, according to a new study.

The study revealed that rats grow a thicker fur coat and can actually lower their body temperature to compensate for a colder environment, reports Wired.com.

The University of Sydney study was conducted to determine whether exposure to chronic cold, level of activity, or an interaction between the two worked to reduce the body temperature of an endotherm such as the bush rat.

Australian bush rats were brought into captivity and acclimated to either a cold environment-12 degree C-or a warm environment-22 degree C.

Each group was then further divided into an exercise group and a sedentary group. Bush rats in the exercise groups were run for 30 minutes on an exercise wheel five days a week.

The bush rats in the cold-acclimated group showed a significantly lower body temperature-reduced by as much as 0.9 degree C-regardless of level of exercise.

The sedentary cold-acclimated rats showed greater fur thickness than the exercised ones; however, both had significantly thicker fur than the warm-acclimated group.

Colder ambient temperature rather than lower levels of activity influenced the bush rats’ response. This decrease in body temperature is due to thermosensation. The current study supports the importance of these environmental sensors distributed throughout the body and skin.

Temperature activates these channels, and previous studies with rodents have shown that blocking the receptors can change how the animal responds to the warmth or cold of its environment.

The reduction in body temperature benefits the exercising bush rat in the cold environment by allowing both maintained activity and energy savings. With a lower body heat to achieve, less energy is spent in keeping warm.

The findings appeared in the Journal of Mammalogy. (ANI)