Neural Circuitry and Plasticity in the Adult Vertebrate Inner Retina

Glutamatergic synapses between retinal bipolar cells and amacrine cells code for transient and sustained events in the visual environment under widely varying conditions of background illumination; i.e. from very light to dark background conditions. The cell types and synaptic mechanisms responsible for coding the transient and sustained information are relatively well described. Recent studies suggest that these synapses are highly plastic in response to environmental stimulation, functionally and structurally remodeling during changes in the ambient lighting conditions bathing the retina. Our current studies of the zebrafish retina are investigating these plastic changes at the bipolar to amacrine cell synapses using a combination of techniques, including patch recording and 2-photon microscopy in the zebrafish retinal slice. We are particularly interested in how the newly discovered endogenous cannabinoid signaling system of the retina controls plasticity at these synapses.