Arcuate nucleus neuropeptide coexpression and connections to gonadotrophin ‐releasing hormone neurones in the female rhesus macaque

The underlying hypothalamic neurocircuitry by which metabolism and feeding regulates reproductive function has been well‐studied in the rodent; however, recent data have demonstrated significant neuroanatomical differences in the human brain. The present study had three objectives, centred on arcuate nucleus neuropeptides regulating feeding and reproduction: (i) to characterise coexpression patterns in the female nonhuman primate; (ii) to establish whether these neuronal populations make potential contacts with gonadotophin‐releasing hormone (GnRH) neurones; and (iii) to determine whether these contacts differ between the low and high GnRH‐releasing states of pre‐puberty and adulthood, respectively. Female nonhuman primates have several coexpression patterns of hypothalamic neuropeptides that differ from those reported in rodents. Cocaine‐ and amphetamine‐regulated transcript (CART) is not coexpressed with pro‐opiomelanocortin but instead with neuropeptide Y (NPY). CART is also expressed in a subpopulation of kisspeptin cells in the nonhuman primate, similar to observations in humans but diverging from findings in rodents. Very few GnRH‐expressing neurones received close appositions from double‐labelled kisspeptin/CART fibres; however, both single‐labelled kisspeptin and CART fibres were in frequent apposition with GnRH neurones, with no differences between prepubertal and adult animals. NPY/agouti‐related peptide (AgRP) coexpressing fibres contacted sig...
Source: Journal of Neuroendocrinology - Category: Endocrinology Authors: Tags: ORIGINAL ARTICLE Source Type: research