Deciphering the spectral coding of neurons provides an important key to understanding the mechanisms of color vision. Although there is a growing body of research on spectral coding in the retina, much less is known about chromatic inputs once they reach central targets. My proposed project focuses on the cortical input of short-wavelength-sensitive cones (scones) by exploring the functional organization and dynamics of s-cone inputs in the primary visual codex (V1) of the tree shrew. In particular, the proposed experiments aim to 1) determine whether stimuli that selectively isolate the s-cones are capable of activating V1 circuits and whether there is a systematic organization of that activity that is different from cortical activation with stimuli that excite the ml-cones, 2) examine the spatial and temporal dynamics of the cortical population response to s-cone mediated signals, 3) compare the laminar distribution of s-cone and ml-cone driven inputs and their degree of convergence onto single V1 neurons. These experiments will explore how activity in the s-cone pathway is represented in V1, providing new insights into the cortical mechanisms that are responsible for color processing.
Johnson, Elizabeth N; Van Hooser, Stephen D; Fitzpatrick, David (2010) The representation of S-cone signals in primary visual cortex. J Neurosci 30:10337-50 |