Synaptic Organization of the Primate Pulvinar Nucleus

University Of Louisville Research Foundation Inc, Louisville KY

Investigators

Abstract

Lay summary In a world that continually supplies us with a multitude of sensory information, the selection and enhancement of important signals is crucial. There is general agreement that the pulvinar nucleus is uniquely involved in this process. However the mechanisms by which the pulvinar carries out this function are, as yet, unknown. Several models of directed attention have proposed that the pulvinar nucleus acts as a hub in a network that integrates inputs from widespread cortical areas to direct attention to salient visual targets. Such models predict that neurons that project to and from different cortical areas, are synaptically connected within the pulvinar nucleus to link diverse signals related to visual spatial location, memory, and motivation. To test this theory, the investigators propose to examine, at the ultrastructural level, connections between the pulvinar nucleus the posterior cingulate gyrus, and the inferior parietal lobule. In addition, they propose to examine the synaptic targets of subcortical inputs from the pretectum, and the pedunculopontine tegmentum. These areas, in which activity is correlated respectively with eye movements and attentional state, are also predicted to contribute to networks underlying visual attention. The results of these studies will help to understand how cortical and subcortical inputs structurally interact within the synaptic circuitry of the primate pulvinar nucleus. By studying these neural circuits in experimental animals, we can begin to understand the mechanisms underlying normal attentional processes, and how they are affected by disease.