Why do wet dogs shake so much?

After getting wet, many hairy mammals-especially dogs– shake off excess water from their fur. Scientists are now getting closer to understanding the neural mechanism underlying wet dog shaking. Using laboratory mice, a team of researchers from the Howard Hughes Medical Institute at Harvard Medical School found that these behaviors are activated when certain mechanoreceptors in the skin are activated. The results are described in detail in The study was published November 7 in the journal Science.

Wet cocktails for dogs – an effective way remove water from the fur, as well as potentially eliminate irritants, mats and parasites.. It works especially well in areas such as the neck and back, which are harder for animals to reach when licking or grooming. Hairy mammals are done 12 types of sensory neurons and each has its own function – to find and interpret different feelings and cause reactions such as trembling. Although this behavior is quite common in several species, the neural mechanisms behind it have been studied. largely unexplored.

(Connected: New evidence suggests dogs can ‘represent’ objects in their minds, just like humans.)

IN new research, the team focused on a type of ultrasensitive touch receptors called Low threshold C-fiber mechanoreceptors (C-LTMR). These receptors act by surrounding hair follicles and are associated with pleasurable affective touch.

First of all, the team used several types of stimuli like oil and water on the backs and necks of mice. After applying the stimuli, the team looked for the response of several mechanosensory neurons.

The team then genetically modified some of the mice. removing most of their C-LTMR. Removing these receptors prevented the mice from shaking, indicating that they are required to control the sensation needed to trigger wet dog shaking.

Next they explored How signals from C-LTMR travel through the nervous system of mice. They traced this path to a group of neurons in the spinal cord. This neural pathway connects to parabrachial nucleus– an area of ​​the brain that helps process pain, touch and temperature. The team then modified the neurons so that they could turn on and off in response to light. It blocked the activity of spinal neurons and allowed them create a map of the path that sensory neurons took.

(Connected: Dogs and wolves remember where you hide food.)

Compared to control mice, the modified mice had 58% reduction in number of cocktails. Blocking activity in the areas of pain, touch, and brain temperature also produced similar results. Mice in the control group continued to scratch and groom themselves normally, suggesting that this is a neural circuit specific to wet dog shaking.

Based on the resultsC-LTMRs are the key sensory players behind wet dog shaking. Future studies of this common behavior may explore whether overactive C-LTMRs add conditions such as skin twitching syndrome in cats. This is when cats suddenly tear their skin and jerk violently. It can also be used when studying skin hypersensitivity in people.