Neuropeptide receptor distributions in male and female vary between female-dominant and egalitarian species.
Allie E Schrock, Mia R Grossman, Nicholas M Grebe, Annika Sharma, Sara M Freeman, Michelle C Palumbo, Karen L Bales, Heather B Patisaul, Christine M Drea
Author Information
Allie E Schrock: Department of Evolutionary Anthropology, Duke University, Durham, NC, USA. ORCID
Mia R Grossman: Department of Psychology & Neuroscience, Duke University, Durham, NC, USA. ORCID
Nicholas M Grebe: Department of Evolutionary Anthropology, Duke University, Durham, NC, USA. ORCID
Annika Sharma: Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
Sara M Freeman: Department of Psychology, University of California Davis, Davis, CA, USA. ORCID
Michelle C Palumbo: Department of Psychology, University of California Davis, Davis, CA, USA.
Karen L Bales: Department of Psychology, University of California Davis, Davis, CA, USA. ORCID
Heather B Patisaul: Biological Sciences Department, NC State University, Raleigh, NC, USA.
Christine M Drea: Department of Evolutionary Anthropology, Duke University, Durham, NC, USA. ORCID
Aggression and its neurochemical modulators are typically studied in males, leaving the mechanisms of female competitive Aggression or dominance largely unexplored. To better understand how competitive Aggression is regulated in the primate brain, we used receptor autoradiography to compare the neural distributions of oxytocin and vasopressin receptors in male and female members of female-dominant versus egalitarian/codominant species within the genus, wherein dominance structure is a reliable proxy of Aggression in both sexes. We found that oxytocin receptor binding in the central amygdala (CeA) was predicted by dominance structure, with the members of three codominant species showing more oxytocin receptor binding in this region than their peers in four female-dominant species. Thus, both sexes in female-dominant show a pattern consistent with the regulation of Aggression in male rodents. We suggest that derived pacifism in stems from selective suppression of ancestral female Aggression over evolutionary time via a mechanism of increased oxytocin receptor binding in the CeA, rather than from augmented male Aggression. This interpretation implies fitness costs to female Aggression and/or benefits to its inhibition. These data establish as a robust model for examining neural correlates of male and female competitive Aggression, potentially providing novel insights into female dominance.
