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Generation of slow waves in the antral region of guinea‐pig stomach ‐ a stochastic process
Author(s) -
Hirst G. D. S.,
Edwards F. R.
Publication year - 2001
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.2001.00165.x
Subject(s) - tetrodotoxin , antrum , interstitial cell of cajal , guinea pig , circular muscle , plateau (mathematics) , biophysics , chemistry , anatomy , stomach , biology , smooth muscle , endocrinology , mathematics , biochemistry , mathematical analysis
1 Slow waves were recorded from the circular muscle layer of the antral region of guinea‐pig stomach. Slow waves were abolished by 2APB, an inhibitor of IP 3 ‐induced Ca 2+ release. 2 When the rate of generation of slow waves was monitored it was found to vary from cycle to cycle around a mean value. The variation persisted after abolishing neuronal activity with tetrodotoxin. 3 When simultaneous recordings were made from interstitial cells in the myenteric region (ICC MY ) and smooth muscle cells of the circular layer, variations in the rate of generation of slow waves were found to be linked with variations in the rate of generation of driving potentials by ICC MY . 4 A preparation was devised which consisted of the longitudinal muscle layer and ICC MY . In this preparation ICC MY and smooth muscle cells lying in the longitudinal muscle layer generated driving potentials and follower potentials, synchronously. 6 Driving potentials had two components, a rapid primary component that was followed by a prolonged plateau component. Caffeine (3 mM) abolished the plateau component; conversely reducing the external concentration of calcium ions [Ca 2+ ] o mainly affected the primary component. 7 Analysis of the variations in the rate of generation of driving potentials indicated that this arose because both the duration of individual driving potentials and the interval between successive driving potentials varied. 8 It is suggested that the initiation of pacemaker activity in a network of ICC MY is a stochastic process, with the probability of initiating a driving potential slowly increasing, after a delay, from a low to a higher value following the previous driving potential.