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: A physiologically-evoked M1-muscarinic depolarization in guinea-pig inferior mesenteric ganglion neurons.
    Author: Anthony TL, Kreulen DL.
    Journal: J Auton Nerv Syst; 1994 Mar; 46(3):207-15. PubMed ID: 7912245.
    Abstract:
    The possibility of physiologically-evoked muscarinic excitatory synaptic potentials was examined in the inferior mesenteric ganglion (IMG) with intracellular microelectrodes in vitro. Three types of depolarizing responses were evoked concurrently by colonic distension: (1) fast nicotinic excitatory postsynaptic potentials (EPSPs); (2) an 'intermediate' time course depolarization and (3) a long time course potential that persisted throughout the period of distension. After hexamethonium was superfused over the ganglia the long time course potential was observed in 91% of IMG neurons. Intermediate time course of depolarizations were observed in 100% of IMG neurons and correlated with each propulsive contraction of the distal colon. The intermediate depolarizations had an average amplitude of 1.8 +/- 0.1 mV (n = 175 individual events; 27 preparations) with an average duration of 11.9 +/- 0.8 sec (n = 28 individual events). The intermediate time course synaptic potentials were accompanied by an increase in input resistance of 15% (n = 6). Superfusion of atropine (1 microM; n = 6) on the IMG or the M1-selective antagonist pirenzepine (1 microM; n = 5) abolished the intermediate time course synaptic potentials during distension. Superfusion of the M2-selective antagonist AF-DX 116 (1 microM; n = 4) had no effect. In all preparations examined, distension-induced intermediate time course depolarizations were blocked by tetrodotoxin (TTX) (3 microM). Pressure ejection of carbachol (1 mM, 60-100 ms pulses) evoked depolarizations of similar amplitude (6.5 +/- 0.7 mV; n = 18) and duration to the intermediate depolarizations observed during propulsive contractions.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]