Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-16T15:30:57.663Z Has data issue: false hasContentIssue false
  • English
  • Français

Cannabinoid receptors on goldfish retinal bipolar cells: Electron-microscope immunocytochemistry and whole-cell recordings

Published online by Cambridge University Press:  01 May 2000

STEPHEN YAZULLA ,
KEITH M. STUDHOLME ,
HELEN H. McINTOSH  and
SHIH-FANG FAN
STEPHEN YAZULLA
Affiliation:
Department of Neurobiology and Behavior, University at Stony Brook, Stony Brook, NY
KEITH M. STUDHOLME
Affiliation:
Department of Neurobiology and Behavior, University at Stony Brook, Stony Brook, NY
HELEN H. McINTOSH
Affiliation:
Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, MO
SHIH-FANG FAN
Affiliation:
Department of Neurobiology and Behavior, University at Stony Brook, Stony Brook, NY
Get access Rights & Permissions [Opens in a new window]

Abstract

Cannabinoid CB1 receptors are distributed throughout the CNS and interact with GABA, glutamate, and dopamine systems. Cannabinoids have effects on the visual system, some of which may have a retinal component, particularly the enhancement of photosensitivity. We used immunocytochemistry and whole-cell recording to study cannabinoids in the goldfish retina. Immunoblots of an antiserum against amino acids (1-14) of the rat CB1 receptor produced a single band in goldfish retina at about 70 kDa. Light microscope immunocytochemistry of CB1 receptor immunoreactivity (CB1R-IR) revealed intense staining of Müller cells and weaker staining of ON bipolar cells (verified with double labeling with PKC-IR) and the outer and inner plexiform layers. Ultrastructural analysis revealed that CB1R-IR was localized intracellularly as well as on the plasma membrane of photoreceptor terminals, bipolar cell terminals and, rarely, amacrine cell boutons. Membrane-associated CB1R-IR was restricted to cone pedicles at sites removed from the synaptic ribbon. Regarding bipolar cells, membrane-associated CB1R-IR was found at 93% of the synaptic terminals in sublamina b (ON-type) and only at 33% of the synaptic terminals in sublamina a (OFF-type). Whole-cell recordings from large ON-type Mb bipolar cells showed that the delayed rectifier (IK(V)) was rapidly and reversibly inhibited by 1 μM of the cannabinoid agonists CP 54490 and (+)-WIN 55212-2, effects blocked completely by the antagonist SR 141716A (1 μM). Inhibition of IK(V) in the Mb bipolar cells by cannabinoids should result in a more tonic ON response to increments of light. As such, cannabinoids may play a role in modulating the temporal aspects of signaling in the retina.

Keywords

CannabinoidRetinaBipolar cellEicosanoidPotassium channels
Type
Research Article
Information
Visual Neuroscience , Volume 17 , Issue 3 , May 2000 , pp. 391 - 401
Copyright
2000 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)