Related Experiment Video
Updated: Aug 2, 2026

Gastrointestinal Motility Monitor (GIMM)
Published on: December 2, 2010
A modified single sucrose gap. Junction potentials and electrotonic potentials in gastrointestinal smooth muscles
1Department of Anatomy and Embryology, University College London, United Kingdom.
Abstract:
Modifications were made to a rubber membrane type of single sucrose gap apparatus, which facilitated recording of isometric tension in smooth muscle preparations and which allowed electrotonic potentials and junction potentials to be evoked simultaneously. Nonadrenergic, noncholinergic inhibitory junction potentials were recorded from the circular muscle of the rat cecum. The amplitude of the inhibitory junction potential was linearly dependent on membrane potential, and inhibitory junction potential reversal potential was consonant with the expected potassium equilibrium potential. Cholinergic excitatory junction potentials were recorded in a preparation of the guinea pig cecum. It has been discussed as to how this type of modified single sucrose gap will be useful for pharmacological investigations into neuromuscular transmission, in addition to being a useful technique for examining actions of drugs and chemicals on smooth muscles.
Related Concept Videos
Action Potentials
Gap Junctions
Electrical Synapses
Gap junctions allow the current to pass directly from one cell to the next. In contrast, in the chemical synapse, the neurotransmitters carry the information through the synaptic cleft from one neuron to the next. They consist of two...
Gap Junctions
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Gastric Motility
Peristaltic Waves and Chyme Formation
Upon food entry, the stomach initiates...

