Grant: Operating Grant

Schizophrenia is among the most debilitating disorders. Most of its burden is due to associated memory deficits. Weakening of frontal brain cell connections is considered to underlie these deficits. However, this has not been directly demonstrated in patients yet. Paired associative stimulation (PAS) is a novel brain stimulation method that assesses the strength of brain cell connections in humans. PAS has been mostly applied to the motor brain region that controls hand movements, in which case, the strength of brain connections can be measured using the electrical activity of the hand muscles. PAS has yet to be applied to the frontal brain region of patients with schizophrenia. The challenge has been in the ability to measure the strength of frontal brain cell connections since there is no direct output measure such as the electrical activity of the hand muscles when PAS is applied to the motor brain region. This challenge can now be overcome using our technique of combining brain stimulation with the direct measurement of electrical activity from the brain. Using this technique, the strength of brain cell connections can be directly measured from the brain. We propose to use PAS in combination with the direct measurement of brain electrical activity to compare in 30 participants with schizophrenia and 30 age and sex matched healthy participants the strength of brain cell connections in the frontal brain region and how it relates to memory. The originality of this proposal lies in the fact that it aims at directly assessing the strength of brain cell connections in patients with schizophrenia. It also uses innovative methodology that is based on brain stimulation. Finally, it intends to advance current knowledge on the cause of schizophrenia and associated memory deficits. Such knowledge will lead to novel treatments that strengthen brain cell connections, enhance memory, and improve the quality of life and function of hundreds of thousands of Canadians.