Optical Imaging of Neural Dynamics in Retina

Optical Imaging of Neural Dynamics in Retina

John S. George1 and Xin-Cheng Yao2

1 Biological and Quantum Physics Group, Los Alamos National Laboratory

2 Department of Biomedical Engineering, University of Alabama at Birmingham

Abstract: We have demonstrated high-resolution spatiotemporal optical imaging of neural activity in populations of retinal neurons. Near-infrared light imaging disclosed fast intrinsic optical responses tightly associated with neural activity in frog retina. Optical responses highly correlated with a- and b- waves observed in simultaneous electrophysiological measurements, and including both ON and OFF responses, were observed from retina activated by visible light stimuli. Image sequences disclosed dynamic changes of the patterns of retinal neural activities. A bright visible light spot elicited an initial negative-going optical response, which dominated the stimulated retinal area, while positive optical responses were observed in the surrounding area. Prolonged light step stimuli speeded up the rising and resetting phases of the optical responses associated with neural activity. An enhanced response along the perimeter of the stimulated region, which might result from center-surround antagonism of the retina, was observed. This approach holds promise for basic studies of spatiotemporal patterns of information processing by retina, as well as optimization and validation of electroneural stimulation by retinal prosthetic devices.