Caress what a pleasure, the relaxing and regenerating power of gestures. A group of American scholars has reconstructed the nervous circuit that carries the pleasant sensation of a caress from the skin to the brain. All this is the result of more than four years of research carried out on mice by about twenty researchers from the Columbia University and other partner organizations and institutes.
The caress
The study, published in the journal Cell, could pave the way for new targeted therapies to help people suffering from anxiety, depression and autism. Even human skin is in fact equipped with tactile sensors very similar to those of mice called Mrgprb4 and which had already been under scrutiny for some time due to their ability to activate in response to weak stimuli such as the lightest touches. Thanks to optogenetics, US researchers have obtained mice with cells Mrgprb4 genetically modified that can be remotely activated with colored light.
In this way they discovered that the animals, stimulated with a beam of blue light, tended to flex their backs, assuming the classic posture they show when they are sexually receptive. There 'caress of light' aroused so much pleasure that the mice themselves went spontaneously under the lamp. In animals in which Mrgprb4 cells were eliminated, however, a collapse of sexual receptivity was observed.
Reward neurons
Using the fiber photometry technique, the team then identified the reward neurons, that light up in the brain in response to impulses from Mrgprb4 cells. The bridge that connects the sensors of the skin with the brain are the Gpr83 neurons of the spinal cord, already identified in another study by Harvard researchers.
(Source Abdus-Saboor Lab/Zuckerman Institute)
