These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Pelvic afferent reflex control of rectal motility and lumbar colonic efferent discharge mediated by the pontine sympatho-inhibitory region in guinea pigs.
    Author: Takaki M, Neya T, Nakayama S.
    Journal: Pflugers Arch; 1985 Feb; 403(2):164-9. PubMed ID: 3982967.
    Abstract:
    Rectal motility and the efferent discharge of lumbar colonic nerves (LCED) have previously been shown to be affected by reflex activity activated by rectal stimulation. The sensory limb of this reflex is represented by afferent fibers in pelvic nerves. The present study revealed that this reflex is modulated by supraspinal sympatho-inhibitory regions. Pelvic afferent stimulation led to rectal contraction through the withdrawal of a tonic inhibitory influence of lumbar colonic nerves. The supraspinal region responsible for this antagonism of the rectal-inhibitory colonic nerve activity was localized to the pons. Neither the intravenous administration of atropine nor that of guanethidine (and Eisai compound 865-123, another adrenergic neuron blocking agent) effected the ability of pelvic afferent stimulation to inhibit tonic discharge of lumbar colonic efferent nerves; nevertheless, both agents eliminated the mechanical response of the rectum to stimulation of pelvic afferents. These observations suggest that lumbar sympathetic nerves may tonically inhibit the release of acetylcholine from excitatory neurons in the rectal myenteric plexus. We conclude that descending fibers from the pons are activated as a result of pelvic afferent nerve stimulation. These descending pontine fibers in turn inhibit the firing of sympathetic lumbar colonic nerves. Removal of this tonic restraint leads to rectal contraction.
    [Abstract] [Full Text] [Related] [New Search]