A Rat's Tale

Physiology of their tails

On a cold winter night, the sky is black and the streets are empty. A family sits by the fire, covered in blankets, enjoying each other’s company. Unbeknownst to them, there is a small hole in their attic hosting another family, the rats. In order to survive, the rats always had to steal food from the family. However, today was different. Today was the day the youngest rat got caught and was kicked out of the house. This is the start of a rat’s tale.

The rat is now all alone in the cold with nothing but its fur and tail. Surprisingly, it isn’t the skin or the fur that is keeping the rat warm. It is the tail. A rat’s tail is responsible for thermoregulation using sympathetic vasoconstrictor nerves. The sympathetic nerves regulate blood flows to the tail, which allows it to be a heat exchanger. When the skin and rectum is exposed to cold stimuli, the rat’s central nervous system stimulates the tail to respond by activating fibre tail sympathetic nerve activity (Owens et al., 2002). The neurotransmitter, GABA, shows an increased level, which indicates that it is responsible for inhibition of heat loss under cold ambient temperature (Ishiwata et al., 2005). When the nerves are activated by cold stimuli, blood flow to the tail decreases due to vessel constriction This allows the body to maintain more blood and preserve heat. (Automatictrap, 2020).

Fortunately for this rat, it was able to find its way back home through the small cracks of the house. The rat is no longer in the cold and its body/skin begins to rewarm itself. The central nervous system is no longer responding to the warm stimuli and it has turned itself off. This means that the tail sympathetic nerves are not constricting the blood vessels anymore (Owens et al., 2002). In addition, GABA levels had decreased to very low levels once there was heat exposure, which means that it is responsible for disinhibition of heat production (Ishiwata et al., 2005).Since rats cannot sweat or pant like other mammals, their tail is important for maintaining the proper temperature when it gets hot. The blood returns back to their tail causing heat dissipation from the body (Automatictrap, 2020). A rat’s tail resembles an on/off controller when stimulated by temperature (Dawson & Keber, 1979).

The rat happily sleeps after enduring such a harsh day. The end.