title: Topohistology of sympathetic and parasympathetic nerve fibers in branches of the pelvic plexus: an immunohistochemical study using donated elderly cadavers.
abstract: Although the pelvic autonomic plexus may be considered a mixture of sympathetic and parasympathetic nerves, little information on its composite fibers is available. Using 10 donated elderly cadavers, we investigated in detail the topohistology of nerve fibers in the posterior part of the periprostatic region in males and the infero-anterior part of the paracolpium in females. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were used as parasympathetic nerve markers, and tyrosine hydroxylase (TH) was used as a marker of sympathetic nerves. In the region examined, nNOS-positive nerves (containing nNOS-positive fibers) were consistently predominant numerically. All fibers positive for these markers appeared to be thin, unmyelinated fibers. Accordingly, the pelvic plexus branches were classified into 5 types: triple-positive mixed nerves (nNOS+, VIP+, TH+, thick myelinated fibers + or -); double-positive mixed nerves (nNOS+, VIP-, TH+, thick myelinated fibers + or -); nerves in arterial walls (nNOS-, VIP+, TH+, thick myelinated fibers-); non-parasympathetic nerves (nNOS-, VIP-, TH+, thick myelinated fibers + or -); (although rare) pure sensory nerve candidates (nNOS-, VIP-, TH-, thick myelinated fibers+). Triple-positive nerves were 5-6 times more numerous in the paracolpium than in the periprostatic region. Usually, the parasympathetic nerve fibers did not occupy a specific site in a nerve, and were intermingled with sympathetic fibers. This morphology might be the result of an "incidentally" adopted nerve fiber route, rather than a target-specific pathway.
authors.affiliation: Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hinata
authors.affiliation: Department of Urology, Hiroshima University School of Medicine, Hiroshima, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hieda
authors.affiliation: Division of Gynecology, Ishikawa Prefectural Central Hospital, Kanazawa, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Division of Internal Medicine, Iwamizawa Kojin-kai Hospital, Iwamizawa, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Murakami
authors.affiliation: Department of Anatomy, Tokyo Dental College, Tokyo, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Abe
authors.affiliation: Department of Urology, Hiroshima University School of Medicine, Hiroshima, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Matsubara
authors.affiliation: Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
authors.affiliation: Department of Urology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Fujisawa
keywords: Human anatomy; Neuronal nitric oxide synthase; Pelvic autonomic nerve plexus; Tyrosine hydroxylase; Vasoactive intestinal polypeptide