Sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for CRF type 1 and type 2 receptors: A comparative study of eusocial naked mole-rats and solitary Cape mole-rats.
Various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (CRF) family of peptides and receptors in the mammalian telencephalon. This study has mapped and compared the telencephalic distribution of the CRF receptors, CRF1 and CRF2 , and two of their ligands, CRF and urocortin 3, respectively, in African mole-rat species with diametrically opposed social behavior. Naked mole-rats live in large eusocial colonies that are characterized by exceptional levels of social cohesion, tolerance, and cooperation in burrowing, foraging, defense, and alloparental care for the offspring of the single reproductive female. Cape mole-rats are solitary; they tolerate conspecifics only fleetingly during the breeding season. The telencephalic sites at which the level of CRF1 binding in naked mole-rats exceeds that in Cape mole-rats include the basolateral amygdaloid nucleus, hippocampal CA3 subfield, and dentate gyrus; in contrast, the level is greater in Cape mole-rats in the shell of the nucleus accumbens and medial habenular nucleus. For CRF2 binding, the sites with a greater level in naked mole-rats include the basolateral amygdaloid nucleus and dentate gyrus, but the septohippocampal nucleus, lateral septal nuclei, amygdalostriatal transition area, bed nucleus of the stria terminalis, and medial habenular nucleus display a greater level in Cape mole-rats. The results are discussed with reference to neuroanatomical and behavioral studies of various species, including monogamous and promiscuous voles. By analogy with findings in those species, we speculate that the abundance of CRF1 binding in the nucleus accumbens of Cape mole-rats reflects their lack of affiliative behavior.
Reproductive Neurobiology, Division of Women's Health, School of Medicine, King's College London, London SE1 1UL, United Kingdom.
Clive W
CW
Coen
Reproductive Neurobiology, Division of Women's Health, School of Medicine, King's College London, London SE1 1UL, United Kingdom.
Theodosis
T
Kalamatianos
Reproductive Neurobiology, Division of Women's Health, School of Medicine, King's College London, London SE1 1UL, United Kingdom.|Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa.
Maria K
MK
Oosthuizen
Reproductive Neurobiology, Division of Women's Health, School of Medicine, King's College London, London SE1 1UL, United Kingdom.
Ravi
R
Poorun
School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS, United Kingdom.
Christopher G
CG
Faulkes
Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002, South Africa.
Nigel C
NC
Bennett
D000818:Animals; D001345:Autoradiography; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D019577:Mole Rats / Q000378:metabolism* / Q000523:psychology*; D010784:Photomicrography; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism; D012919:Social Behavior; D013045:Species Specificity; D013687:Telencephalon / Q000378:metabolism*; D054832:Urocortins / Q000378:metabolism; D000099052:CRF Receptor, Type 1
C101531:CRF receptor type 2; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; D000099052:CRF Receptor, Type 1; D003346:Corticotropin-Releasing Hormone
Cape mole-rats; Georychus capensis; Heterocephalus glaber; amygdala; bed nucleus of the stria terminalis; cerebral cortex; cooperation; corticotrophin-releasing factor (CRF); corticotrophin-releasing hormone (CRH); habenula; hippocampus; naked mole-rats; nucleus accumbens; septum; social behavior; urocortin