Intrinsic neurons in the human ovary

Mammalian ovarian function is regulated by both hormonal inputs and direct neural influences. Recent studies have shown that, in addition to the extri nsic innervation, the ovaries of nonhuman primates and a strain of rats con tain a discrete population of intrinsic neurons. In the present study, we u sed histological and immunohistochemical approaches to identify the presenc e of neuronal cell bodies in the fetal and neonatal human ovary. Neurons co ntaining neurofilament immunoreactivity were detected in the hilum and medu lla of the ovary at all ages studied, ranging from 24 weeks of gestation to 10 months of postnatal age. Most of them coexpressed the low affinity neur otrophin receptor (p75(NTR)), and some were catecholaminergic, as determine d by their content of immunoreactive tyrosine hydroxylase (TH), the rate-li miting enzyme in catecholamine biosynthesis. The presence of intrinsic neur ons in the human ovary, similar to those previously found in other species, indicates that they may be engaged in regulating common, phylogenetically conserved, ovarian functions. It also raises the possibility that their dys function may contribute to the manifestation of particular ovarian patholog ies.