%0 Journal Article
%~ PubMed
%A Tsai, David
%A Chen, Spencer
%A Protti, Dario A
%A Morley, John W
%A Suaning, Gregg J
%A Lovell, Nigel H
%T Responses of retinal ganglion cells to extracellular electrical stimulation, from single cell to population: model-based analysis.
%B PLoS One
%D 2012
%C United States
%I Public Library of Science
%V 7
%N 12
%P e53357
%@ 1932-6203
%X 
%Z FOR Codes: 90399 60601 60602


%0 Journal Article
%~ PubMed
%A Middleton, T P
%A Protti, D A
%T Cannabinoids modulate spontaneous synaptic activity in retinal ganglion cells.
%B Visual neuroscience
%D 2011
%C United Kingdom
%I Cambridge University Press
%V 28
%N 5
%P 393-402
%@ 1469-8714
%X 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 ??M), 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.
%Z FOR Codes: 110906


%0 Journal Article
%~ PubMed
%A Di Marco, Stefano
%A Nguyen, Vincent A
%A Bisti, Silvia
%A Protti, Dario A
%T Permanent functional reorganization of retinal circuits induced by early long-term visual deprivation.
%B The Journal of Neuroscience
%D 2009
%C United States
%I Society for Neuroscience
%V 29
%N 43
%P 13691-13701
%@ 1529-2401
%X Early sensory experience shapes the functional and anatomical connectivity of neuronal networks. Light deprivation alters synaptic transmission and modifies light response properties in the visual system, from retinal circuits to higher visual centers. These effects are more pronounced during a critical period in juvenile life and are mostly reversed by restoring normal light conditions. Here we show that complete light deprivation, from birth to periods beyond the critical period, permanently modifies the receptive field properties of retinal ganglion cells. Visual deprivation reduced both the strength of light responses in ganglion cells and their receptive field size. Light deprivation produced an imbalance in the ratio of inhibitory to excitatory inputs, with a shift toward larger inhibitory conductances. Ganglion cell receptive fields in visually deprived animals showed a spatial mismatch of inhibitory and excitatory inputs and inhibitory inputs were highly scattered over the receptive field. These results indicate that visual experience early in life is critical for the refinement of retinal circuits and for appropriate signaling of the spatiotemporal properties of visual stimuli, thus influencing the response properties of neurons in higher visual centers and their processing of visual information.
%Z FOR Codes: 110906


%0 Book Section
%A Leamey, Catherine
%A Protti, Dario
%A Dreher, Bogdan
%T Comparative Survey of the Mammalian Visual System with Reference to the Mouse
%B Eye, Retina, and Visual System of the Mouse
%D 2008
%C United States
%I MIT Press
%V 
%N 
%P 35-60
%@ 9780262033817
%E Chalupa, Leo M.
%E Williams, Robert W.
%X 
%Z FOR Codes: 111301


%0 Journal Article
%~ Isi
%A Dumitrescu, O. N.
%A Protti, D. A.
%A Majumdar, S.
%A Zeilhofer, H. U.
%A Wassle, H.
%T Ionotropic glutamate receptors of amacrine cells of the mouse retina.
%B Visual Neuroscience
%D 2006
%C United Kingdom
%I Cambridge University Press
%V 23
%N 1
%P 79-90
%@ 0952-5238
%X 
%Z FOR Codes: 110904