Cholinergic nerves in mouse uterus.

The topographical distribution of cholinergic nerve fibres in the uterus was studied in normal as well as chemically sympathectomized mice. Our analysis was performed using both transverse sections and whole mounts, in order to analyse the distribution of cholinergic nerves within the various layers of the uterus and to study the morphology of nerve plexuses that supply the organ. Cholinergic nerve fibres were found chiefly around the uterine artery and its primary ramifications. Nerve fibres coming from arterial plexuses are distributed to the myometrium and more infrequently to the endometrium. Groups of acetylcholinesterase positive ganglion cells were located in the cervix. The distribution pattern of the cholinergic innervation of mouse uterus shows important topographical differences. In the tubal end of uterine horn the innervation is poor and cholinergic nerve fibres are organized in a sparse plexus. The number and the density of uterine nerves increase gradually proceeding toward the cervix. The cervix shows the richest innervation. The findings that observed nerve fibres are unaltered by chemical sympathectomy and are revealed using short incubation times suggest their parasympathetic nature.