Le rôle des interactions corticales inhibitrices au niveau des colonnes, des régions et des aires chez les sujets sains et malades

 

Reza Farivar-Mohseni

Institut de recherche du Centre universitaire de santé McGill

 

Domaine : neurosciences, santé mentale et toxicomanies

Programme chercheurs-boursiers - Junior 1

Concours 2015-2016

Normal brain processing involves both excitatory and inhibitory processes. The role of inhibition in normal brain function is poorly understood. Inhibition and excitation are balanced in normal brain function, but following injury or disease, the balance is disrupted and excessive inhibition of weakened tissue can prevent recovery. This program of research aims to understand the mechanisms of inhibition at multiple cortical levels.

First, at the early stages of sensory processing, information is processed in small modules called columns. Columns interact competitively with one another, and in disease, one column may excessively inhibit other columns. We are developing means of measuring and manipulating inhibitory interactions. Second, at a slightly higher level, clusters of columns that together process one portion of our visual field interact competitively with other adjacent clusters. Third, at yet a level higher, feedback signals from other cortical areas modulate activity in the earlier areas. Brain injury disrupts the balance of excitation and inhibition in these interactions, resulting in excessive inhibition in inter-regional and inter-areal interactions which then impede recovery.

A second theme in this program of research is to understand the nature and extent of inhibitory interactions between regions and areas and the role they play in recovery of function. The results of this focused, integrated, and multidisciplinary program on the role of inhibition and the columnar, regional, and areal scale have fundamental implications for our understanding of cortical function, its disruption following injury and disease, and optimal methods of recovering lost function.