Visual System Organization and Development

Vanderbilt University, Nashville TN

Investigators

Linked publications, trials & patents

Abstract

tn our working model of visual information pro cessing, we hypothesize that there are three segregated paraIlet pathways [magnocell utar (M), parvocetlular (P), and koniocelIutar (K)] from the laterat genicuI ate nucteus (LGN) to primer y visual cortex (V1), form ing both dedicated and multi-functional systems and networks. Within this scheme, separate output layer s and compartments of V1 have distinct modes for utilizing signals from eli three input pathways and generating output signals that contribute to the dynamics and functional maps of extrastriate areas. tn light of this model, the major effort of our project is to understand how parallel LGN pathway s in primates contribute to the properties of V1 and its extrastriate targets. This proposal focuses on all three LGN relays and how their inputs affect V 1 and higher visual centers, but places added em phasis on the K pathway considering the fact that it has been, until recently, largely ignored. Our specific aims are designed to test hypotheses generated by our working modet. In Aim I, we will determine the number of physiologically distinct K channels and the classes of retinal gangtion ceils that project to K LGN layers. In Aim II, we wilt determine the relationship between LGN relay cells and the dynamics and functional maps found within V 1. In Aim tit, we will apply the same techniques Jtilized in Aim II to determine how LGN relays contribute to the dynamics and functional maps found wi thin extrastfiate areas V2, V3, and DM/V3a. The results of our proposed studies wilI contribute important new nformation to our understanding of the fundamentals of how the brain processes visual information and of _rain architecture in general.