Canada Brain Power

Tag: Douglas Institute

  • A reduction in the number of connexions between brain cells is seen in the early stages of psychosis and is associated with negative symptoms.

    A reduction in the number of connexions between brain cells is seen in the early stages of psychosis and is associated with negative symptoms.

    Brain Star Award Feature: Maira Belen Blasco, Douglas Research Institute, McGill University, won this prize based on the excellence of the research and its potential benefits to the health of Canadians. Brain Star Awards are presented by the Canadian Association for Neuroscience (CAN) and the Canadian Institutes of Health’s Institute of Neurosciences, Mental Health and Addiction

    Schizophrenia is a complex psychiatric disorder typically emerging in adolescence or early adulthood. It is thought to occur because of alteration in the maturation or pruning of connexions between neurons called synapses. While this theory, called the synaptic theory is supported by genetic, stem cell and studies of brain of deceased patients, direct evidence to support this theory in living patients was doubtful. Maira Belen Blasco, working in the laboratory of Dr. Romina Mizrahi at the Douglas Research Centre, McGill University, investigated whether difference in the density of synapses could be seen in first-episode psychosis (FEP) and in clinical high risk (CHR) patients using positron emission tomography (PET). They found that synaptic density was reduced during the early stages of psychosis and its risk states and associated with negative symptoms.

    Read the full story here: https://canadabrainpower.com/brain-star-award-winner-maira-belen-blasco/

    Featured scientific articleMaira Belen Blasco

    Blasco MB, Nisha Aji K, Ramos-Jiménez C, Leppert IR, Tardif CL, Cohen J,  Pablo M Rusjan , Romina Mizrahi. Synaptic Density in Early Stages of Psychosis and Clinical High Risk. JAMA Psychiatry. 2024 Nov 13; Published online: https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2825648

    https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2825648

  • Study linking depression to specific altered brain cells opens door to new treatments

    Study linking depression to specific altered brain cells opens door to new treatments

    Research on rare post-mortem brain samples reveals altered gene activity, shedding light on depression’s biological roots

    Researchers at McGill University and the Douglas Institute have identified two specific types of brain cells that are altered in people with depression.

    The study, published in Nature Genetics, opens the door to developing new treatments that target these cells and deepens our understanding of depression, a leading cause of disability worldwide that affects more than 264 million people.

    “This is the first time we’ve been able to identify what specific brain cell types are affected in depression by mapping gene activity together with mechanisms that regulate the DNA code,” said senior author Dr. Gustavo Turecki, a professor at McGill, clinician-scientist at the Douglas Institute and Canada Research Chair in Major Depressive Disorder and Suicide. “It gives us a much clearer picture of where disruptions are happening, and which cells are involved.”

    Rare brain bank enables breakthrough

    The researchers used post-mortem brain tissue from the Douglas-Bell Canada Brain Bank, one of the few collections in the world with donated tissue from people who had psychiatric conditions.

    They used single-cell genomic techniques to analyze RNA and DNA from thousands of brain cells, identifying which cells worked differently in depression and what DNA sequences could explain those differences. They studied samples from 59 people who had depression and 41 people without it.

    The results revealed altered gene activity in a certain type of excitatory neuron involved in mood and stress regulation, and in a subtype of microglia cells, which help manage inflammation. In both cell types, many genes were functioning differently in people with depression, suggesting potential disruptions in these key brain systems.

    By pinpointing brain cells affected in depression, the study adds new insight into its biological basis and, more broadly, challenges lingering misconceptions about the disorder.

    “This research reinforces what neuroscience has been telling us for years,” Turecki said. “Depression isn’t just emotional, it reflects real, measurable changes in the brain.”

    As a next step, the researchers plan to study how these cellular changes affect brain function and whether targeting them could lead to better therapies.

    About the study

    “Single-nucleus chromatin accessibility profiling identifies cell types and functional variants contributing to major depression” by Anjali Chawla and Gustavo Turecki et al., was published in Nature Genetics.

    The study was funded by Canadian Institutes of Health Research, Brain Canada Foundation, Fonds de recherche du Québec – Santé and Healthy Brains, Healthy Lives initiative at McGill University.

    This study was published in the Journal Nature Genetics

    10.1038/s41588-025-02249-4