Article date: 1992/4/1
PubMed ID: 1375285
Journal name: Journal of neurophysiology (ISSN: 0022-3077)
1. The effect of vasoactive intestinal polypeptide (VIP) on bipolar cells and ganglion cells freshly dissociated from the rat retina was studied under voltage clamp with the use of patch-clamp recording in the whole-cell configuration. 2. Application of VIP (1-100 microM) by itself resulted in no detectable current response in either bipolar cells or ganglion cells. However, gamma-aminobutyric acid (GABA)-activated macroscopic current responses elicited in both neuronal populations were potentiated on superimposed exposure to the neuropeptide. 3. GABA-activated chloride currents and muscimol-induced current responses were similarly potentiated on exposure to VIP, suggesting a synergistic interaction between VIP and GABAA receptor mechanisms. 4. We postulate that VIP plays a neuromodulatory role by regulating the excitability of inner retinal neurons and in this way modulates the efficacy of synaptic transmission in the retina.
Author List: Veruki M L, Yeh H H
Publication Types: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.
Substances mentioned in the article: Chloride Channels; Ion Channels; Membrane Proteins; Receptors, GABA-A; Muscimol; Vasoactive Intestinal Peptide; gamma-Aminobutyric Acid;
Mesh terms: Aging; Animals; Animals, Newborn; Chloride Channels; Drug Synergism; Electric Conductivity/drug effects; In Vitro Techniques; Ion Channels/physiology; Kinetics; Membrane Potentials/drug effects; Membrane Proteins/drug effects; Muscimol/pharmacology; Rats; Receptors, GABA-A/drug effects; Retina/cytology; Retinal Ganglion Cells/drug effects; Time Factors; Vasoactive Intestinal Peptide/pharmacology; gamma-Aminobutyric Acid/pharmacology;