Distribution and morphology of luteinising hormone-releasing hormone neurones in a species of wild antelope, the springbok (Antidorcas marsupialis).
The distribution and morphology of luteinising hormone-releasing hormone (LHRH) neurones varies between species. The primary purpose of this study was to characterize the distribution and morphology of the LHRH system in a species of antelope, the springbok. This wild antelope has a well-defined social structure in which reproductive activity is confined to a few dominant, territorial rams. We also sought to determine whether social or reproductive status could be accounted for by differences in the distribution or morphology of hypothalamic LHRH neurones. Eleven anoestrous female, nine breeding territorial male (TM) and eight "bachelor" male (BM) springbok were obtained, and their reproductive and body conditions were assessed. By using standard immunocytochemical techniques, the LHRH system was visualised in the brains of four animals from each group. Immunoreactive neurones were located in a continuum from the septum to the arcuate nucleus, with the majority at the level of the organum vasculosum of the lamina terminalis. Neither the distribution nor the number of cells differed among the three groups. Furthermore, the area of LHRH perikarya was similar in both groups of males, suggesting that reproductive differences between TMs and BMs lie at another level of the neuroendocrine axis. The anoestrous females had significantly larger neurones than males (TM plus BM). This may reflect a sex difference in the LHRH system of this wild antelope. However, an alternative explanation is that the male/female difference is related to the comparatively inactive reproductive neuroendocrine state of the females.
Robinson
J E
JE
Department of Neurobiology, The Babraham Institute, Cambridge, United Kingdom. jane.robinson@bbsrc.ac.uk
Skinner
D C
DC
Skinner
J D
JD
Haupt
M A
MA
D000704:Analysis of Variance; D000818:Animals; D000835:Animals, Wild / Q000033:anatomy & histology* / Q000502:physiology; D000866:Antelopes / Q000033:anatomy & histology* / Q000502:physiology; D002452:Cell Count; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis*; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000737:chemistry; D009474:Neurons / Q000737:chemistry*; D012098:Reproduction / Q000502:physiology
D007987:Gonadotropin-Releasing Hormone