We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Cannabinoids modulate spontaneous synaptic activity in retinal ganglion cells.
- Authors
MIDDLETON, T. P.; PROTTI, D. A.
- Abstract
The endocannabinoid (ECB) system has been found throughout the central nervous system and modulates cell excitability in various forms of short-term plasticity. ECBs and their receptors have also been localized to all retinal cells, and cannabinoid receptor activation has been shown to alter voltage-dependent conductances in several different retinal cell types, suggesting a possible role for cannabinoids in retinal processing. Their effects on synaptic transmission in the mammalian retina, however, have not been previously investigated. Here, we show that exogenous cannabinoids alter spontaneous synaptic transmission onto retinal ganglion cells (RGCs). Using whole-cell voltage-clamp recordings in whole-mount retinas, we measured spontaneous postsynaptic currents (SPSCs) in RGCs in adult and young (P14–P21) mice. We found that the addition of an exogenous cannabinoid agonist, WIN55212-2 (5 μM), caused a significant reversible reduction in the frequency of SPSCs. This change, however, did not alter the kinetics of the SPSCs, indicating a presynaptic locus of action. Using blockers to isolate inhibitory or excitatory currents, we found that cannabinoids significantly reduced the release probability of both GABA and glutamate, respectively. While the addition of cannabinoids reduced the frequency of both GABAergic and glutamatergic SPSCs in both young and adult mice, we found that the largest effect was on GABA-mediated currents in young mice. These results suggest that the ECB system may potentially be involved in the modulation of signal transmission in the retina. Furthermore, they suggest that it might play a role in the developmental maturation of synaptic circuits, and that exogenous cannabinoids are likely able to disrupt retinal processing and consequently alter vision.
- Subjects
RETINAL ganglion cells; CANNABINOIDS; SYNAPSES; PATCH-clamp techniques (Electrophysiology); CENTRAL nervous system; GABA; GLUTAMIC acid; LABORATORY mice
- Publication
Visual Neuroscience, 2011, Vol 28, Issue 5, p393
- ISSN
0952-5238
- Publication type
Article
- DOI
10.1017/S0952523811000198