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

Abstract

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.