Three Neuroscience Graduate Program students earn PhDs
The Division of Medical Sciences and the Neuroscience Graduate Program (NGP) would like to congratulate Dr. Carla Liria Sánchez-Lafuente (Caruncho / Kalynchuk Lab), Dr. Erin Gräfe (Christie Lab), and Dr. Hannah Reid (Christie Lab) on earing their PhDs after successfully defending their dissertations. Read on to learn more about each of their research projects.
Dr. Carla Liria Sánchez-Lafuente
“Investigation of Sex Differences in Hypothalamic Reelin and its Implications on Stress-Related Pathology”
Women are twice more likely to suffer from stress-related disorders like depression, and when depression occurs during the post-partum period, it can have detrimental effects on the child. Yet, most preclinical studies investigating new therapeutic avenues for the disorder focus mostly on males. Dr. Liria Sánchez-Lafuente's dissertation helps fill this crucial research void by expanding our understanding of sex-based disparities in brain function, particularly in the context of stress regulation and depression development.
Her work presents novel findings on sexually dimorphic neurochemistry, focusing on the levels of a synaptic protein called reelin within critical stress-regulating regions of the brain. Additionally, it offers initial insights into the potential antidepressant effects of peripheral reelin in a preclinical model of post-partum depression. These discoveries hold significant promise in bridging the gap between laboratory discoveries and clinical applications, ultimately enhancing the translational potential of scientific advancements from bench to bedside.
Dr. Liria Sánchez-Lafuente's research was funded by the Canadian Institutes of Health Research (CIHR) and the Natural Sciences and Engineering Research Council of Canada (NSERC), as well as by a Mitacs research training award.
Dr. Erin Gräfe
“Postnatal Choline Supplementation Ameliorates Synaptic Plasticity Deficits Following Prenatal Ethanol Exposure in a Sex-Specific Manner”
Dr. Gräfe’s dissertation examines how choline supplements could help restore synaptic plasticity in offspring with fetal alcohol spectrum disorder (FASD). FASD is caused by prenatal ethanol exposure (PNEE), and it is one of the leading causes of neurodevelopmental impairment. One of the most notable is a deficit in hippocampal synaptic plasticity, which negatively affects learning and memory.
PNEE reduces long-term potentiation (LTP) – a process that strengthens synapses – in juvenile males. Dr. Gräfe found that choline supplements improved some LTP deficits in males. The treatments also further increased LTP in females, who did not experience the same deficits as their male counterparts. The treatment also insignificantly decreased the amount of long-term depression (LTD) – a process that weakens synapses – in males. While these changes did not persist into adulthood, choline supplements did alter the hippocampal LTP threshold. While questions remain – such as how choline supplementation leads to these improved hippocampal outcomes at a synaptic level, whether these occur in a sex-dependent manner, and if any changes will persist – Dr. Gräfe’s data further supports choline as a treatment for PNEE and suggests that extended choline treatment may produce more long-lasting changes.
Dr. Gräfe’s research was funded by an NSERC Canadian Graduate Scholarship – Doctoral (CGS-D) from NSERC; a CIHR Project Grant, on which she was a trainee co-investigator; and an award from the National Institute on Alcohol Abuse and Alcoholism (R37AA012446) granted to Dr. Jennifer Thomas and Dr. Brian Christie.
Dr. Hannah Reid
“Prenatal THC Exposure Has Lasting Detrimental Effects on the Rat Hippocampus”
Prenatal cannabis exposure is as common as prenatal alcohol exposure, yet it is understudied. And with the recent legalization of cannabis, it is doubly important to understand the substance’s effects on offspring.
Dr. Reid’s dissertation focuses on the hippocampus, which is central to learning and memory. It’s also a part of the brain known to be affected acutely by the drug; the hippocampus is rich in cannabinoid type 1 receptors, which are targeted by the psychoactive component of cannabis. In her dissertation, Dr. Reid examines how prenatal THC exposure affects hippocampal synaptic plasticity, different populations of hippocampal interneurons, and dendritic spines. She also looks at how morphological characteristics of microglia are altered, as well as how inhibitory and excitatory markers co-localize with the cannabinoid type 1 receptor. Her findings show that not only that there are alterations in all these areas, but there are regional and sex differences in many of these changes. This work shows that there are consequences of prenatal cannabis exposure into adulthood.
Dr. Reid’s research was funded by a CIHR Project Grant, on which she was a trainee co-investigator, and an award from the National Institute on Alcohol Abuse and Alcoholism (R37AA012446) granted to Dr. Jennifer Thomas and Dr. Brian Christie.
Image: Taylor Richardson-Snowden (Chrisite), Penny Young (Nashmi), Hannah Reid (Christie), and Alejandra Raudales (Brown)