Descending projections from the nucleus raphe obscurus to pudendal motoneurons in the male rat

Gerlinda E. Hermann, Jacqueline C. Bresnahan, Gregory Holmes, Richard C. Rogers, Michael S. Beattie

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Previous physiological and behavioral studies have shown that the nucleus raphe obscurus (nRO) modulates pelvic floor reflex function (Yamanouchi and Kakeyama [1992] Physiol. Behav. 51:575-579; Beattie et al. [1996] Soc. Neurosci. Abstr. 22:722.4; Holmes et al. [1997] Brain Res. 759:197-204). In the present study, small injections of fluorescent tracers were used to investigate direct descending projections from the rostral and caudal portions of the brainstem nRO to retrogradely labeled pudendal motoneurons (MN) in the male rat. The caudal nRO projects into the ventral and lateral funiculi of the spinal cord, with arborizations in the thoracic intermediolateral cell column; in laminae VII, IX, and X of the lumbosacral cord; and in the sacral parasympathetic nucleus (SPN). Many identified external anal sphincter and ischiocavernosus MNs appeared to be in direct apposition with fibers originating from the caudal nRO; and more than half of the bulbospongiosus MNs that were identified appeared to receive such descending input. In addition to the nRO spinal autonomic and pudendal motoneuronal targets, projections were observed to regions of the intermediate gray that contain interneurons organizing the pelvic floor reflexes and to MN pools that are involved in functionally related somatic activities. Finally, several neurons in the lumbar enlargement were labeled retrogradely with FluoroRuby after injections into the nRO and the immediately adjacent reticular formation. Thus, the nRO may be in a position to modulate the coordinated actions of autonomic preganglionic and functionally related skeletal MN activity involved in sexual and eliminative reflex functions.

Original languageEnglish (US)
Pages (from-to)458-474
Number of pages17
JournalJournal of Comparative Neurology
Volume397
Issue number4
DOIs
StatePublished - Aug 10 1998

Fingerprint

Motor Neurons
Reflex
Pelvic Floor
Injections
Reticular Formation
Anal Canal
Interneurons
Nucleus Raphe Obscurus
Brain Stem
Spinal Cord
Thorax
Neurons
Brain

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

Cite this

Hermann, Gerlinda E. ; Bresnahan, Jacqueline C. ; Holmes, Gregory ; Rogers, Richard C. ; Beattie, Michael S. / Descending projections from the nucleus raphe obscurus to pudendal motoneurons in the male rat. In: Journal of Comparative Neurology. 1998 ; Vol. 397, No. 4. pp. 458-474.
@article{61a7802a5c1e4cd68b2367cb1146048a,
title = "Descending projections from the nucleus raphe obscurus to pudendal motoneurons in the male rat",
abstract = "Previous physiological and behavioral studies have shown that the nucleus raphe obscurus (nRO) modulates pelvic floor reflex function (Yamanouchi and Kakeyama [1992] Physiol. Behav. 51:575-579; Beattie et al. [1996] Soc. Neurosci. Abstr. 22:722.4; Holmes et al. [1997] Brain Res. 759:197-204). In the present study, small injections of fluorescent tracers were used to investigate direct descending projections from the rostral and caudal portions of the brainstem nRO to retrogradely labeled pudendal motoneurons (MN) in the male rat. The caudal nRO projects into the ventral and lateral funiculi of the spinal cord, with arborizations in the thoracic intermediolateral cell column; in laminae VII, IX, and X of the lumbosacral cord; and in the sacral parasympathetic nucleus (SPN). Many identified external anal sphincter and ischiocavernosus MNs appeared to be in direct apposition with fibers originating from the caudal nRO; and more than half of the bulbospongiosus MNs that were identified appeared to receive such descending input. In addition to the nRO spinal autonomic and pudendal motoneuronal targets, projections were observed to regions of the intermediate gray that contain interneurons organizing the pelvic floor reflexes and to MN pools that are involved in functionally related somatic activities. Finally, several neurons in the lumbar enlargement were labeled retrogradely with FluoroRuby after injections into the nRO and the immediately adjacent reticular formation. Thus, the nRO may be in a position to modulate the coordinated actions of autonomic preganglionic and functionally related skeletal MN activity involved in sexual and eliminative reflex functions.",
author = "Hermann, {Gerlinda E.} and Bresnahan, {Jacqueline C.} and Gregory Holmes and Rogers, {Richard C.} and Beattie, {Michael S.}",
year = "1998",
month = "8",
day = "10",
doi = "10.1002/(SICI)1096-9861(19980810)397:4<458::AID-CNE2>3.0.CO;2-0",
language = "English (US)",
volume = "397",
pages = "458--474",
journal = "Journal of Comparative Neurology",
issn = "0021-9967",
publisher = "Wiley-Liss Inc.",
number = "4",

}

Descending projections from the nucleus raphe obscurus to pudendal motoneurons in the male rat. / Hermann, Gerlinda E.; Bresnahan, Jacqueline C.; Holmes, Gregory; Rogers, Richard C.; Beattie, Michael S.

In: Journal of Comparative Neurology, Vol. 397, No. 4, 10.08.1998, p. 458-474.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Descending projections from the nucleus raphe obscurus to pudendal motoneurons in the male rat

AU - Hermann, Gerlinda E.

AU - Bresnahan, Jacqueline C.

AU - Holmes, Gregory

AU - Rogers, Richard C.

AU - Beattie, Michael S.

PY - 1998/8/10

Y1 - 1998/8/10

N2 - Previous physiological and behavioral studies have shown that the nucleus raphe obscurus (nRO) modulates pelvic floor reflex function (Yamanouchi and Kakeyama [1992] Physiol. Behav. 51:575-579; Beattie et al. [1996] Soc. Neurosci. Abstr. 22:722.4; Holmes et al. [1997] Brain Res. 759:197-204). In the present study, small injections of fluorescent tracers were used to investigate direct descending projections from the rostral and caudal portions of the brainstem nRO to retrogradely labeled pudendal motoneurons (MN) in the male rat. The caudal nRO projects into the ventral and lateral funiculi of the spinal cord, with arborizations in the thoracic intermediolateral cell column; in laminae VII, IX, and X of the lumbosacral cord; and in the sacral parasympathetic nucleus (SPN). Many identified external anal sphincter and ischiocavernosus MNs appeared to be in direct apposition with fibers originating from the caudal nRO; and more than half of the bulbospongiosus MNs that were identified appeared to receive such descending input. In addition to the nRO spinal autonomic and pudendal motoneuronal targets, projections were observed to regions of the intermediate gray that contain interneurons organizing the pelvic floor reflexes and to MN pools that are involved in functionally related somatic activities. Finally, several neurons in the lumbar enlargement were labeled retrogradely with FluoroRuby after injections into the nRO and the immediately adjacent reticular formation. Thus, the nRO may be in a position to modulate the coordinated actions of autonomic preganglionic and functionally related skeletal MN activity involved in sexual and eliminative reflex functions.

AB - Previous physiological and behavioral studies have shown that the nucleus raphe obscurus (nRO) modulates pelvic floor reflex function (Yamanouchi and Kakeyama [1992] Physiol. Behav. 51:575-579; Beattie et al. [1996] Soc. Neurosci. Abstr. 22:722.4; Holmes et al. [1997] Brain Res. 759:197-204). In the present study, small injections of fluorescent tracers were used to investigate direct descending projections from the rostral and caudal portions of the brainstem nRO to retrogradely labeled pudendal motoneurons (MN) in the male rat. The caudal nRO projects into the ventral and lateral funiculi of the spinal cord, with arborizations in the thoracic intermediolateral cell column; in laminae VII, IX, and X of the lumbosacral cord; and in the sacral parasympathetic nucleus (SPN). Many identified external anal sphincter and ischiocavernosus MNs appeared to be in direct apposition with fibers originating from the caudal nRO; and more than half of the bulbospongiosus MNs that were identified appeared to receive such descending input. In addition to the nRO spinal autonomic and pudendal motoneuronal targets, projections were observed to regions of the intermediate gray that contain interneurons organizing the pelvic floor reflexes and to MN pools that are involved in functionally related somatic activities. Finally, several neurons in the lumbar enlargement were labeled retrogradely with FluoroRuby after injections into the nRO and the immediately adjacent reticular formation. Thus, the nRO may be in a position to modulate the coordinated actions of autonomic preganglionic and functionally related skeletal MN activity involved in sexual and eliminative reflex functions.

UR - http://www.scopus.com/inward/record.url?scp=0032504771&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032504771&partnerID=8YFLogxK

U2 - 10.1002/(SICI)1096-9861(19980810)397:4<458::AID-CNE2>3.0.CO;2-0

DO - 10.1002/(SICI)1096-9861(19980810)397:4<458::AID-CNE2>3.0.CO;2-0

M3 - Article

VL - 397

SP - 458

EP - 474

JO - Journal of Comparative Neurology

JF - Journal of Comparative Neurology

SN - 0021-9967

IS - 4

ER -