Honours and directed studies students research intermittent fasting, concussion, and more

Each year, UVic honours and directed studies students conduct their research projects in the Division of Medical Sciences. Here’s a quick look at the work seven students completed in the Swayne, Christie, and Brown labs this past year.   

honoursstudents.jpg
Erin McDonagh, James Choi, Ana de Lucas Rius, Konrad Suesser, and Samantha Perreault are some of the honours/directed studies students researching in the Division's Swayne, Christie, and Brown labs this year.

Ana de Lucas Rius (Swayne Lab)

Topic: Effect of pannexin 1 knock-out on dendritic spine morphology and synaptic function

My research goal was to determine if the pannexin 1 knock-out had an effect on dendritic spine morphology and, consequently, on synaptic function. I analyzed multiple confocal images of apical dendrites from the somatosensory cortex of two model types, focusing primarily on measuring spine head diameter. The data obtained suggested that spines in one model type present a different head diameter distribution. Future research will allow us to locate the subpopulation of spines responsible for these differences and to broaden our knowledge in the relationship between pannexin 1 and dendritic spine dynamics.

 

Sarah Ebert (Swayne Lab)

Topic: Cellular and synaptic excitability in primary neuronal cultures

Long-term potentiation is thought to be a basis for memory formation in the brain. Key interactions between NMDA and AMPA receptors are involved in mediating synaptic excitability and long-term potentiation. In order to observe the effects of long-term potentiation on synapses, we induced chemical long-term potentiation in primary neuronal cultures and measured the levels of AMPA and NMDA receptors, as well as their subunit composition using western blots.

 

James Choi (Christie Lab)

Topic: Effects of intermittent fasting on synaptic plasticity in the lateral perforant path of the dentate gyrus

Intermittent fasting (IF) is a dietary restriction regimen that involves alternating periods of eating with fasting. Studies have shown that IF increases long-term potentiation, a form of synaptic plasticity, of neural transmission in different regions of the hippocampus in the brain. Using in-vitro electrophysiology techniques in the lateral perforant path of the dentate gyrus, models following a three-week IF protocol were found to have a statistically significant increased level (50% increased) of long-term potentiation when compared to controls. 

 

Konrad Suesser (Christie Lab)

Topic: Effects of intermittent fasting on synaptic plasticity in the medial perforant path of the dentate gyrus

While research has shown that IF enhances synaptic plasticity in various hippocampal regions, the medial perforant pathway of the dentate gyrus is one region that has still not been thoroughly studied. Using in-vitro electrophysiology techniques in the medial perforant pathway, models following a three-week IF protocol were found to have a statistically significant increased levels of long-term potentiation when compared to controls. Additionally, they were found to weigh significantly less than controls at the end of the IF protocol and gained weight at a much slower rate than controls.

Konrad presented this research at UVic’s 2019 Honours Fest, where he won first place biology presenter.

 

Erin C. McDonagh (Christie Lab)

Topic: Hippocampal and optic tract damage produced by mild traumatic brain injury

Concussions are the most common form of mild traumatic brain injury (mTBI). Having a single mTBI significantly increases an individual’s risk for incurring additional injuries, and there is growing concern that this is associated with increased symptom severity and comorbidity across the lifespan. Adolescents and young adults are at a disproportional risk for mTBI, and mTBI may have severe consequences on the developing brain. In this study, we used a novel awake closed head injury (ACHI) paradigm to produce repeated mTBI in models. Neurological assessment indicated transient deficits that resemble clinical concussion symptoms. Behavioural analyses revealed significant effects of ACHI on spatial memory and learning. Histological analysis indicated that repeated mTBI produces significantly more damage in hippocampus and optic tracts. Taken together, these data provided insight into the pathophysiological changes and behavioural correlates of concussion, and the regions of the brain which may be particularly vulnerable to mTBI.

 

Samantha T. Perreault (Christie Lab)

Topic: Effects of repeated concussion on spatial learning and spatial memory

 

Callie Green (Brown Lab)

Topic: Role of ADAM17 in regulating microglial remodelling