Role of social touch and social memory in organizing naked mole-rat colonies

Project Summary/Abstract The East African naked mole-rat is arguably the most social animal in the mammalian kingdom, maintaining decades long harmonious communal living with upwards of hundreds of colony members. Most mammals, including humans, are highly social and cooperation during social interactions is a critical component of our daily lives. Unfortunately, in many diseases of the nervous system, including autism, schizophrenia, and chronic depression, sociability is greatly diminished, and the mechanisms as to why remain poorly defined. Understanding neuronal mechanisms that facilitate social engagement in a highly social animal, the naked mole-rat, could provide valuable new insights to this problem, that can complement work being done in more traditional model organisms. We hypothesize that touch is an essential sensation in naked mole-rats that allows the animals to navigate complex social interactions such as recognizing and keeping memories of large numbers of colony members. We have keyed in on touch because these animals are blind, most other senses are diminished, and they have evolved an exquisitely sensitive tactile system from the periphery to the sensory cortex. In our preliminary studies that serve as rationale for this proposal and support our hypothesis, we find that naked mole-rats engage in an active form of face-to-face interaction tens of thousands of times per day, and the area of their hippocampus dedicated to social memory appears greatly expanded. Thus, we are envisioning a model whereby touch is used to create maps of individuals in their world, sending powerful inputs to an expanded hippocampal network, allowing the animals to quickly identify and remember other animals to perform communal tasks in harmony. This is a completely new direction for my lab, working in a non-traditional model organism and studying neural circuits that are new to us. However, we strongly believe the upside of this work is high, and since these animals are mammals, we will find generalizable principles that can increase our fundamental understanding of key neural mechanisms for social recognition, social memory, and pro-social behaviors more broadly. Indeed, neuroscience is filled with examples of uncovering general principles from studying animals with extreme adaptations that make them ideally suited for the problem at study. We have developed tools and approaches to perform modern neuroscience experiments in naked mole-rats and firmly believe the time is ripe to tackle this fundamental problem within the social neuroscience field.