Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-4-8
pubmed:abstractText
We examined descending reflex pathways in the rat colon using intracellular recording techniques. Inhibitory junction potentials (IJPs) were recorded from circular smooth muscle when descending pathways were excited by combined mucosal compression and distension. IJPs were reduced to 71% of control when synaptic transmission was blocked in the oral stimulation chamber of a divided organ bath suggesting that two reflex pathways exist, the one involving descending sensory neurones and the other involving descending interneurones. Hexamethonium (200 micromol L(-1)) in the recording chamber abolished reflexly evoked IJPs, while in the stimulation chamber, it was as effective as synaptic blockade. When hexamethonium was added to a chamber lying between the stimulation and recording chambers, it again sharply depressed IJPs to 27% of control; an extent similar to synaptic blockade. A P2 receptor antagonist did not reveal any purinergic neurotransmission. Either granisetron (5-HT3 receptor antagonist, 1 micromol L(-1)) or SB204070 (5-HT4 receptor antagonist, 1 micromol L(-1)) in the stimulation chamber significantly decreased IJPs; these decreases were not additive. We conclude that some sensory neurones and interneurones in rat colon have long anally projecting axons and that acetylcholine, acting via nicotinic receptors, is the primary neurotransmitter from sensory neurones, to inhibitory motor neurones and between interneurones.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1350-1925
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
161-71
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:12680915-Action Potentials, pubmed-meshheading:12680915-Animals, pubmed-meshheading:12680915-Colon, pubmed-meshheading:12680915-Female, pubmed-meshheading:12680915-Hexamethonium, pubmed-meshheading:12680915-Interneurons, pubmed-meshheading:12680915-Male, pubmed-meshheading:12680915-Muscle, Smooth, pubmed-meshheading:12680915-Neurons, Afferent, pubmed-meshheading:12680915-Nicotinic Antagonists, pubmed-meshheading:12680915-Organ Culture Techniques, pubmed-meshheading:12680915-Physical Stimulation, pubmed-meshheading:12680915-Purinergic P2 Receptor Antagonists, pubmed-meshheading:12680915-Rats, pubmed-meshheading:12680915-Receptors, Nicotinic, pubmed-meshheading:12680915-Receptors, Purinergic P2, pubmed-meshheading:12680915-Receptors, Serotonin, pubmed-meshheading:12680915-Reflex, pubmed-meshheading:12680915-Synapses, pubmed-meshheading:12680915-Synaptic Transmission
pubmed:year
2003
pubmed:articleTitle
Nicotinic transmission at functionally distinct synapses in descending reflex pathways of the rat colon.
pubmed:affiliation
Department of Physiology, University of Melbourne, Parkville VIC, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't