title: Stimulus frequency-dependent inhibition of micturition contractions of the urinary bladder by electrical stimulation of afferent Aβ, Aδ, and C fibers in cutaneous branches of the pudendal nerve.
abstract: We aimed to examine the afferent mechanisms for the reflex inhibition of the rhythmic micturition contractions (RMCs) of the urinary bladder induced by stimulation of the perineal skin afferents in urethane-anesthetized rats. Electrical stimulation (pulse duration: 0.5 ms) was applied to the cutaneous branches of the pudendal nerve (CBPN) at frequencies of 0.1, 1, and 10 Hz for 1 min. Nerve fiber groups were defined by recording compound action potentials from CBPN. Activation of only Aβ fibers (0.2 V) produced an inhibition of RMCs at 7-11 min after the onset of stimulation (late inhibition), at any tested frequency. Additional activation of Aδ fibers (1 V) produced additional early inhibition (immediately after stimulation) at 1 and 10 Hz. Furthermore, additional activation of C fibers (10 V) at 10 Hz completely stopped RMCs for >10 min. This strong inhibition persisted after local application of capsaicin to the stimulating CBPN. We conclude that activities of Aβ, Aδ, and C afferent fibers, without capsaicin-sensitive channels, can contribute to the inhibition of bladder contractions.
authors.affiliation: Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.|Division of Rheumatology and Allergy, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, 173-8606, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Onda
authors.affiliation: Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.
authors.forename: Sae
authors.initials: S
authors.lastname: Uchida
authors.affiliation: Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.|Graduate School of the University of Human Arts and Sciences, Saitama, 339-8539, Japan.
authors.forename: Harue
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan. hhotta@tmig.or.jp.
authors.forename: Harumi
authors.identifier: http://orcid.org/0000-0002-4590-7162
authors.initials: H
authors.lastname: Hotta
mesh_terms: D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D004558:Electric Stimulation; D008297:Male; D060525:Pudendal Nerve / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination / Q000502:physiology*
keywords: Electrical stimulation; Myelinated nerve fibers; Reflexes; Unmyelinated nerve fibers; Urinary bladder