Modulation of arterial muscle contraction in Aplysia by glycine and neuron R14.

Glycine and electrical activity in neuron R14 both enhance the contractility of the anterior aorta of the gastropod Aplysia californica. Glycine and R14 do not seem to cause contraction directly, change membrane permeabilities or alter junctional potentials occurring in the muscle fibers, yet they increase the force of contractions induced by other means. Modulation of muscle contraction is a new function for glycine.