Parietal meet-up: a day of discussion about parietal connectivity and function across species
August 6, 2012
Last week we got together at Cold Spring Harbor with folks from NYU and MIT who share an interest in parietal cortex, but approach it from different points of view. Our lab, with a focus on neural circuits and decision-making, shared recent developments in rodent behavior and electrophysiology. Bijan Pesaran’s lab, from NYU, described their recent work exploring connections between sub-regions of parietal cortex in primate, and their emerging work on identifying neurons in the parietal cortex that project to frontal areas. Finally, Kathy Rockland, an anatomist from MIT, answered our many questions about injections, expression levels, and anatomical landmarks, and then later described her work connecting parietal cortex and subregions of the hippocampus.
At the moment, it is clear that may aspects of posterior parietal cortex are conserved from mouse to rat to monkey to human: in all species, the region gets inputs from similar thalamic nuclei (posterior nucleus in rodents and pulvinar + posterior nucleus in primates), and has feedforward connections to frontal areas and the superior colliculus. One thing that remains unclear is the degree to which species differ in the sub-regions that comprise posterior parietal cortex. In monkey, subdivisions are clear, although there is considerable overlap in the selectivity of neurons in each area. In rodent, the existence of subdivisions remains a mystery. Are they there waiting to be discovered? Or are the neurons in the most medial and lateral portions of the area functionally equivalent? We hope to be able to address these questions in the coming months.
The image below parietal cortex neurons in the rat (From Tomioka & Rockland) as well as a (somewhat incomplete) group photo taken from the cafe at Cold Spring Harbor Lab.