Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

Vascular mild cognitive impairment (vMCI) refers to early changes in memory and thinking caused by a reduction in blood flow to the brain. It is frequently found in individuals with heart disease or its risk factors (e.g., high blood pressure, diabetes) and increases their risk for irreversible memory changes ("dementia"). vMCI is an optimal time to intervene before problems with memory and thinking become severe. Brain cells communicate with each other by using brain chemicals, called neurotransmitters. In the healthy brain, there is a balance between the excitatory and inhibitory neurotransmitters. This balance may be disrupted in individuals with cognitive impairment, in which lower levels of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), is observed. First, I propose to investigate whether lower brain GABA levels is associated with poorer global cognition in vMCI. Brain stimulation and aerobic exercise (AE) may have the potential to correct for this imbalance. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique shown to improve cognition that may alter GABA levels. AE may enhance the effects of tDCS, but this has yet to be studied in vMCI. Second, I propose to investigate whether brain GABA is a biomarker of response to a combined treatment of AE and tDCS in vMCI. GABA levels in the brain will be measured using neuroimaging before and after treatment. This work will help elucidate the role of GABA in vMCI and select participants who may have the most cognitive benefit from AE and tDCS treatment. This work will also help inform the development of future therapies to delay the onset of dementia. In Canada, delaying the onset of dementia by one year can lead to half a million fewer cases by 2050.