A special set of neurons directs mice’s attention to or away from their peers, depending on the situation.
The Kobe University discovery has implications for finding causes for neuropsychiatric conditions such as autism spectrum disorder or schizophrenia.
Social interactions abound with decisions: How much time do we spend with a friend? Do we prioritize time with a friend who looks distressed? Like for all behavior, there are specialized clusters of neurons in the brain that are responsible for fine-tuning such complex behavior, and it is known that developmental defects in these areas are related to neuropsychiatric disorders such as autism spectrum disorder or schizophrenia.
Kobe University neuroscientist Takumi Toru has a long history of research on discovering the neurological basis of these disorders. He says, “We have previously identified in mice a neuron cluster that’s active during social interaction and now we wanted to clarify the role of a specific kind of signal-modulating cell, so-called ‘PV interneurons,’ that we knew are there.” Using an endoscopic camera with its lens implanted directly into the brain of genetically modified mice, Takumi’s team was able to record in real time which neurons were active during different activities. In addition, they also introduced genetic modifications that allowed them to specifically tune down the activity of the target neurons.
In the scientific journal Cell Reports, the Kobe University neuroscientists, in collaboration with SATO Masaaki of Kyoto Institute of Technology, now report that mice whose PV interneurons were inhibited exhibited two interesting behavioral characteristics. First, they failed to become familiar with their peers. Normal mice spend less time with individuals they already know than with strangers they meet for the first time, but the ones with inhibited PV interneurons would spend just as much time with peers as with strangers. And second, normal mice, when given the choice between two peers, one stressed and one unstressed, would spend more time with the stressed one. The inhibited mice, however, did not exhibit this consolation behavior.
