Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel; School of Psychological Sciences, Tel-Aviv University, Tel-Aviv, Israel; Department of Integrative Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
Huanjie Sheng
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States
Kimberly LP Long
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
Aline Halliday
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States
The Hospital for Sick Children, Toronto, Neuroscience and Mental Health Program, Toronto, Canada
Anne L Wheeler
The Hospital for Sick Children, Toronto, Neuroscience and Mental Health Program, Toronto, Canada; Physiology Department, University of Toronto, Toronto, Canada
The Hospital for Sick Children, Toronto, Neuroscience and Mental Health Program, Toronto, Canada; Physiology Department, University of Toronto, Toronto, Canada; Canadian Institute for Advanced Research, Toronto, Canada
Carrie Shilyansky
Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, United States
Karl Deisseroth
Department of Bioengineering, Stanford University, Stanford, United States; Department of Psychiatry, Stanford University, Stanford, United States; Howard Hughes Medical Institute, Stanford University, Stanford, United States
Dacher Keltner
Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States; Department of Psychology, University of California, Berkeley, Berkeley, United States
Department of Integrative Biology, University of California, Berkeley, Berkeley, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States; Canadian Institute for Advanced Research, Toronto, Canada
Prosocial behavior, in particular helping others in need, occurs preferentially in response to distress of one’s own group members. In order to explore the neural mechanisms promoting mammalian helping behavior, a discovery-based approach was used here to identify brain-wide activity correlated with helping behavior in rats. Demonstrating social selectivity, rats helped others of their strain (‘ingroup’), but not rats of an unfamiliar strain (‘outgroup’), by releasing them from a restrainer. Analysis of brain-wide neural activity via quantification of the early-immediate gene c-Fos identified a shared network, including frontal and insular cortices, that was active in the helping test irrespective of group membership. In contrast, the striatum was selectively active for ingroup members, and activity in the nucleus accumbens, a central network hub, correlated with helping. In vivo calcium imaging showed accumbens activity when rats approached a trapped ingroup member, and retrograde tracing identified a subpopulation of accumbens-projecting cells that was correlated with helping. These findings demonstrate that motivation and reward networks are associated with helping an ingroup member and provide the first description of neural correlates of ingroup bias in rodents.
