New Technology Assesses Brain Plasticity, May Help with Schizophrenia, Depression

Tarek K. Rajji, M.D., expert in schizophrenia research
Tarek K. Rajji, M.D.

A team of investigators, funded in part by NARSAD Grants, reports exciting progress in clinical experiments designed to assess neuroplasticity in the frontal cortex. The experiments included support from a 2010 NARSAD Young Investigator Grant awarded to Tarek K. Rajji, M.D., of the Centre for Addiction and Mental Health at the University of Toronto in Canada.

Dr. Rajji and colleagues reported in the November 2013 issue of the journal Neuropsychopharmacology that they have developed a method of delivering paired pulses of electrical and transcranial magnetic stimulation (TMS) to the dorsolateral prefrontal cortex in a manner that appears to activate processes involved in brain plasticity. Plasticity refers to the brain’s ability to repair itself and to adapt to changes. While preliminary, these results could provide a new technology―called PAS-induced potentiation―to study what goes wrong in circuits needed for learning and memory, and how to correct these in illnesses like Alzheimer’s disease, schizophrenia, and depression.

PAS―paired associative stimulation―involves the combination of two different types of technologies used to understand and treat brain disorders. Median nerve electrical stimulation is paired with TMS (a technique that uses magnetic stimulation to modulate brain circuits and change brain activity) to the contralateral dorsolateral prefrontal cortex region in the brain, 25 milliseconds after the median nerve stimulation. These paired stimulations are repeated at a low frequency over a period of 30 minutes. Following the paired stimulation, cortical-evoked activity is assessed by combining TMS with electroencephalography (EEG), a technology that records electrical activity along the scalp.

Although their study is too small to generalize results, the researchers suggest their method could lead to new forms of treatments of working memory deficits associated with various disorders. Other recipients of NARSAD Grants who took part in the study include Paul Fitzgerald, Ph.D., Monash University, Australia (2003, 2005 Young Investigator); and Zafiris J. Daskalakis, M.D., Ph.D., University of Toronto (2004, 2006 Young Investigator, 2008 Independent Investigator).

Read an abstract of this research paper.