Organization of the Subdiaphragmatic Vagus Nerve and Its Connection with the Celiac Plexus and the Ovaries in the Female Rat.

Communication between the ovaries and the central nervous system occurs by peripheral innervation through the celiac plexus, superior ovarian nerve, and ovarian plexus nerve. The vagus nerve is involved in regulating the ovaries, but the neuroanatomical pathway that links them is not clear. Adult female rats were used for gross anatomy, acetylcholinesterase histochemistry, and the immunofluorescence analysis of tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), and tryptophan hydroxylase 2 (TPH). The results obtained indicate that the right vagus nerve (RVN) travels parallel and caudal to the esophagus, where three nerve branches were identified. Also, a right vagal plexus (RVP) formed by microganglia was described, establishing communication with the celiac plexus, and was mainly reactive to tyrosine hydroxylase (TH); some serotoninergic and cholinergic neurons were also found. The left vagus nerve (LVN) travels over the esophagus, bifurcates before its insertion into the stomach and enters the RCG. This neuroanatomical and biochemical description of the RVN and LVN in the rat suggests the RVP is formed by presynaptic catecholaminergic terminals and cholinergic neurons. This information could support detailed studies of communication between the vagus nerve and the ovaries and identify the type of neural signaling involved in abdominal control of the vagus nerve.

Intrinsic innervation of the ovary and its variations in the rat senescence process.

Ovarian functions decrease with perimenopause. The ovary has extrinsic innervation, but the neural influence on ovarian functions and dysfunction is not well-studied. The present study aimed to biochemically and morphometrically characterize the intrinsic neurons in ovaries from young adult, middle-aged, and senescent Long Evans CII-ZV rats (3, 12, and 15 months old, respectively). Ovaries were extracted from four rats of each age group (n = 12 total), cryopreserved, and processed for immunofluorescence studies with the primary NeuN/ß-tubulin and NeuN/tyrosine hydroxylase (TH) antibodies. The soma area and number of intrinsic neurons in the ovarian stroma, surrounding follicles, corpus luteum, or cyst were evaluated. The intrinsic neurons were grouped in cluster-like shapes in ovarian structures. In senescent rats, the intrinsic neurons were mainly localized in the ovarian stroma and around the cysts. The number of neurons was lower in senescent rats than in young adult rats (p < 0.05), but the soma size was larger than in young adult rats. Immunoreactivity to TH indicated the presence of noradrenergic neurons in the ovary with the same characteristics as NeuN/ß-tubulin, which indicates that they are part of the same neuronal group. Taken together, the findings indicate that the intrinsic neurons may be related to the loss of ovarian functions associated with aging.