My research focuses on neuronal regulation of cardiac function. Specifically, I am interested in how neurotransmitters (chemicals released by nerve cells to communicate with one another) can modulate the activity of neurons located within the heart which in turn regulate heart rate and the strength of heart contractions. To investigate these questions, I make use of several different neurobiological techniques, including immunohistochemistry, electrophysiology, and biochemical techniques. Currently, I'm investigating two specific questions.
My previous studies have demonstrated that the immune system can interact with neurons that control cardiac function. For example, an allergic reaction involving the heart (cardiac anaphylaxis) appears to directly affect the activity of neurons located within the heart itself. For our current work, we are expanding this question to ask how chronic heart disease, which would include increased stimulation of the immune system as well as the sympathetic nervous system, can alter neuronal function. More specifically, we hypothesize that chronic heart disease, such as occurs with myocardial infarction (blockage of coronary blood vessels) or pressure overload (which could occur with chronic hypertension) leads to a remodeling of the intrinsic cardiac nervous system. To study this, we use animals with models of chronic heart disease and examine the electrical responses of these neurons to neurotransmitters, neuropeptides and other bioactive signalling molecules. Our preliminary studies indicate that chronic heart disease alters the sensitivity of these neurons to specific chemicals, which may result in an increased ability of the nervous system to reduce cardiac activity.
In addition to changes in electrical activity, we are also looking for changes in protein expression in these neurons with disease. Specific proteins appear to be upregulated with disease and we can measure these changes with standard biochemical techniques, such as Western blots and PCR to detect mRNA.
To learn more about one of my student's research, click this link to see a video slide show about the lab!