Mole-rats (of the Bathyergidae family) provide a unique taxonomic group for studying many aspects of neurobiology. In this family, ecological constraints have led to diverse social and reproductive strategies. Eusociality occurs in two species of Bathyergidae rodents; naked mole-rats (Heterocephalus glaber) and Damaraland mole-rats (Fukomys damarensis). The females of these two eusocial species are at the extreme end of the socially-induced infertility continuum whereby ovulation is physiologically blocked. This family provides an ideal model to glean insight into the neurobiological mechanisms of reproductive suppression, eusocial behaviour and neuroplasticity. In this thesis, I report that: (1) naked mole-rats display substantial numbers of kisspeptin-immunoreactive cell bodies in the rostral periventricular region of the third ventricle, paraventricular hypothalamic nucleus, arcuate nucleus and dorsomedial nucleus, irrespective of reproductive state, sex or presence of gonads, (2) reproductive naked mole-rats display significantly higher number of kisspeptin-immunoreactive cell bodies in the rostral periventricular region of the third ventricle and paraventricular hypothalamic nucleus than subordinates, (3) subordinate Damaraland mole-rats have an absence of a RFamide neuronal population that is found in abundance in reproductive Damaraland mole-rats, with no effect of gonadectomy or sex differences, (4) the presence of a sexually monomorphic population of hypothalamic tyrosine hydroxylase neurones indicates the lack of sexual differentiation in the brains of naked mole-rats, (5) the shared occurrence of oxytocin and its receptor in the nucleus accumbens of both eusocial naked mole-rats and eusocial Damaraland mole-rats indicates the possibility of convergent evolution in this family, (6) two novel locations for vasopressin receptor binding in the brains of Damaraland mole-rats have evolved independently during the divergence of this species from a common ancestor, and (7) naked mole-rats have a remarkably low rate of adult hippocampal neurogenesis, a low rate that is shared with other long-lived, group-living animals.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:631298 |
| Date | January 2012 |
| Creators | Zhou, Shuzhi |
| Publisher | King's College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://kclpure.kcl.ac.uk/portal/en/theses/aspects-of-molerat-neurobiology-rodentia-bathyergidae(e6856271-64fd-40c9-a6f6-77d3dfefc618).html |
Page generated in 0.002 seconds