CIHR graduate scholarships fund research on how psychedelics drugs, vaporized cannabis, and maternal immune activation affect the brain

Three members of the Tremblay Lab received Canada Graduate Scholarships from the Canadian Institutes of Health Research (CIHR) to study the effects of psychedelics drugs, vaporized cannabis, and maternal immune activation on the brain. The combined value of these scholarships is $140,000 over three years.

PhD candidate Jared VanderZwaag (pictured, right) received three years of funding through the Canadian Graduate Scholarship – Doctoral (CGS-D) program for his work focused on understanding the impacts of psychedelics drugs on microglia, the brain’s immune cells. Clinical research on psychedelic substances has undergone a renaissance in recent years as many of these drugs, such as psilocybin and LSD, have demonstrated surprising ability to treat a wide array of psychological disorders, including mood disorders.

It is hypothesized that the unique therapeutic effects of psychedelic substances come from their ability to induce rapid growth in neurons, rescuing key circuitry that is typically degraded in mood disorders. However, their ability to alter microglial behaviour is yet to be investigated. Researchers suggest microglia could play a role in the development and recovery from mood disorders as these cells are critical to shaping the brain’s neurocircuitry—specifically, they have been shown to digest synapses and release growth factors.  

Using various techniques to visualize microglia and measure their protein expression, Jared will investigate the impact of acute and chronic treatment of psilocybin on microglia in both acute and chronic stress models of mood disorders. Understanding how these unique drugs work is key to understanding the neurobiology underlying psychological disorders and developing effective treatments for individual’s suffering from these conditions in Canada.

First-year master’s student Colin Murray (pictured, centre) received funding through the Canadian Graduate Scholarship – Master’s (CGS-M) program. This award will support his pursuit of discovering how vaporized cannabis alters the cells responsible for maintaining myelin in the adult and aged brain. Myelin is a lipid-rich sheath that drastically increases the speed of electrical impulses along the axons of neurons, and it is essential for proper communication between different regions of the brain. The process responsible for creating and maintaining myelin relies on nearly all cell types in the brain. However, these regulatory roles become less efficient and myelin declines as we get older, which may contribute to some of the brain function deficits we see with age.

Senior citizens are increasing their consumption of cannabis faster than any other age group in Canada, but it’s relatively unknown what sort of impact cannabis could have on the cells needed for myelination and the overall process of myelination—be it positive, neutral, or negative. This project, which will be done in collaboration with Dr. Jibran Khokhar from University of Western Ontario, will help fill in that knowledge gap.

First-year master’s student Sophia Loewen (pictured, left) also received funding from the CGS-M program for her research on the effects of maternal immune activation (MIA) on microglia during fetal development. MIA occurs when the body of a pregnant person undergoes an immune response after they are exposed to a stimulus that induces inflammation (e.g., chronic psychological stress, some unbalanced diets, and viral infection like COVID-19). This inflammatory response during pregnancy can affect fetal neurodevelopment and increases the risk of neurodevelopmental disorders such as schizophrenia and autism spectrum disorders in the exposed offspring.

Microglia, as the immune cells of the brain, play many important roles throughout our lifespan, but they are especially important in development as they contribute to building and shaping the connections between neurons. Previous research from the Tremblay Lab discovered a subtype of these cells called dark microglia, which are overreactive and abundant in offspring exposed to MIA. These dark microglia are suggested to have strong connections to neurodevelopmental disorders; for instance, they have been observed in human brains of individuals with schizophrenia. To study the roles of dark microglia in the mechanisms underlying the outcomes of MIA on the brain and behaviour, Sophia’s project will investigate dark microglia across key developmental time points in offspring exposed to MIA. She will conduct this research using a series of state-of-the-art imaging techniques available in the Tremblay Lab, and she will eventually investigate treatments targeting relevant microglial subsets.

The CGS-M and CGS-D are administered jointly by Canada’s three granting agencies: the CIHR, the Natural Sciences and Engineering Research Council (NSERC), and the Social Sciences and Humanities Research Council (SSHRC). Jared, Colin, and Sophia all received their funding from CIHR. This federal funding agency supports researchers, trainees, and organizations conducting health research in Canada that aims to improve health outcomes for all Canadians. CIHR awards fund research across a wide range of health-related disciplines, including biomedical research, clinical research, health services research, and social and cultural determinants of health. These awards are highly competitive and are designed to support research excellence, innovation, and impact in the health field.

Photo caption: Pictured (L-R) are Sophia Loewen, Colin Murray, and Jared VanderZwaag of the Tremblay Lab.