Social control of brain morphology in a eusocial mammal

• DOI: 10.1073/pnas.0610344104
• Publication Date: 2007-06-08T00:54:06Z
• Authors: Melissa M. Holmes; Greta J. Rosen; Cynthia L. Jordan; Geert J. de Vries; Bruce D. Goldman; Nancy G. Forger
• Keywords: Eusociality; Mammal; Sexual dimorphism

Social status impacts reproductive behavior in diverse vertebrate species, but little is known about how it affects brain morphology. We explore this the naked mole-rat, a species with most rigidly organized hierarchy among mammals. Naked mole-rats live large, subterranean colonies where breeding restricted to single female and small number of males. All other members colony, as subordinates, are reproductively suppressed. Subordinates can become breeders if removed from colony placed an opposite sex partner, nature individuals never attain status. examined brains subordinate both sexes, including several regions linked reproduction shown be sexually dimorphic Stereological analyses revealed that neural morphology depends on status, such breeders, regardless sex, had more cells than subordinates ventromedial nucleus hypothalamus larger volume bed stria terminalis, paraventricular nucleus, medial amygdala. Several were unaffected. Surprisingly, males females did not differ any measure. These findings provide evidence change social triggers considerable remodeling indicate rather has predominant role determining structure remarkably mammal.