title: Vasoactive intestinal polypeptide modulates GABAA receptor function in bipolar cells and ganglion cells of the rat retina.
abstract: 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.
authors.affiliation: Program in Neuroscience, University of Rochester School of Medicine and Dentistry, New York 14642.
authors.forename: M L
authors.initials: ML
authors.lastname: Veruki
authors.forename: H H
authors.initials: HH
authors.lastname: Yeh
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D018118:Chloride Channels; D004357:Drug Synergism; D004553:Electric Conductivity / Q000187:drug effects; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology*; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
chemical_list: D018118:Chloride Channels; D007473:Ion Channels; D008565:Membrane Proteins; D011963:Receptors, GABA-A; D009118:Muscimol; D014660:Vasoactive Intestinal Peptide; D005680:gamma-Aminobutyric Acid