We would like to understand how large systems of neurons represent and process information. Our efforts have concentrated on the vertebrate retina. Visual perception derives from the action potentials transmitted to the brain through the two optic nerves, each containing about one million fibers. How is the information about our visual environment encoded at this stage of the nervous system? How does the retina generate that representation from the optical image projected onto its photoreceptor layer? And what operations might later stages of the visual system perform on these signals in order to extract the features of interest?
In order to decipher the concerted function of such a large neuronal circuit, one needs to monitor many of the interacting elements simultaneously. We have developed an instrument that uses a flat array of microelectrodes to record simultaneously the action potentials of about 100 retinal ganglion cells in a region of 0.5 mm diameter. Depending on the local ganglion cell density, this can represent a sizeable fraction of the entire retinal output. We are using this method, together with classical electrophysiological and anatomical techniques, to study how various features of a complex visual image are encoded in the set of spike trains the retinal ganglion cells send to the brain.
Selected Publications:
Meister, M., Pine J. and Baylor, D.A. (1995). Concerted Signaling by Retinal Ganglion Cells. Science 270: 1207-1210.
Meister, M. (1996). Multineuronal codes in retinal signaling. Proc. Natl. Acad. Sci. USA 93:609-614.
Smirnakis, S. M., M. J. Berry, D. K. Warland, W. Bialek, and M. Meister (1997). Adaptation of Retinal Processing to Image Contrast and Spatial Scale. Nature 386:69-73.