CPIN Alumni News

Dr. Catharine Mielnik (Pharmacology & Toxicology, Dr. Amy Ramsey)

Catharine MielnikCongratulations to CPIN alumna and Postdoctoral Fellow Dr. Catharine Mielnik from the lab of Dr. Amy Ramsey in the Department of Pharmacology & Toxicology on her recent publication in Molecular Psychiatry. The study, authored by several CPIN members and students and entitled “Consequences of NMDA Receptor Deficiency Can be Rescued in the Adult Brain”, was published in Molecular Psychiatry on August 17, 2020. This study was the culmination of Dr. Catharine Mielnik's doctoral dissertation in Dr. Amy Ramsey's laboratory; from generation of the novel mouse model to the characterization of its rescue. It was a large collaborative study that included other CPIN members (Drs. Evelyn Lambe, Ali Salahpour, and Ruth Ross) and students (Mary Binko, Yuxiao Chen, Katheron Intson, and Rehnuma Islam).
The study addressed a critical question in the treatment of neurodevelopmental disorders: when is the best time to treat these types of disorders? Following the development of a novel mouse model, and assessing multiple developmental ages for intervention, they found that Cre-mediated reversal of gene knockdown led to robust molecular, biochemical and behavioural improvements. Excitingly, genetic rescue in adult mice was as effective at improving cognition as interventions in juvenile and adolescent mice. This finding provides evidence that adult interventions for neurodevelopmental disorders like autism and schizophrenia can be effective, even for cognitive deficiencies that are historically treatment-resistant. The implications of this work are long-ranging: what was originally believed to be a rigid and static adult brain is actually quite plastic and responsive to change.
The publication is available here:
Catharine Mielnik is currently a Postdoctoral Fellow at the University of Toronto in the Department of Pharmacology & Toxicology, with CPIN member Dr. Ruth Ross. Her Postdoctoral work has focused on pre-clinical validation of cannabinoid-targeting pharmacological compounds in models of neuropsychiatric disorders. With the recent legalization of cannabis in Canada, the implication of this work is broad: from what do constituents of cannabis do to the brain, to novel drug discovery in targeting the cannabinoid system in disease states. This work has garnered attention at local and international conferences, winning the International Cannabinoid Research Society Presentation Award, and also an Excellence in Poster Presentation Award through CPIN. This work has also led to a patent for a novel allosteric modulator of Cannabinoid Receptor 1 (CB1), resulted in a first-author paper in Neuropsychopharmacology, and sparked numerous local and international collaborations for the newly developed research program.