Because most of these systems operate to maintain certain variables within "physiological" limits they are continuously monitoring the variables (blood pressure, pO2, pH) and adjusting the output to the appropriate level. For instance, when presented with hypoxia the respiratory system makes adjustments in respiration, arterial pressure and blood flow to maintain normal arterial oxygen levels.
The neural reflex pathways that control cardio-respiratory function are prime material for studying adaptation or "plasticity" because the neural reflexes that control these functions all undergo short and long term changes in response to environmental conditions, changes in hormonal levels, or under a variety of pathological situations. Because we can monitor the function of individual autonomic reflex pathways, we can actually understand how a change in expression of particular ion channels, transmitters, receptors leads to adaptation of the reflex to maintain homeostasis in the face of normal or pathological stresses.
We have two major areas of focus. We are examining the cellular basis for adaptations in the neural control of cardiac rhythm in a simple mammalian circuit composed of only four neurons. In another area we are using a model of intermittent hypoxia to understand the transient and chronic cellular changes that occur in sleep apnea. We use a combination of electrophysiological, immunohistochemical, biochemical, imaging and molecular techniques, as well as mathematical modeling, to accomplish these goals.
Please visit Research to learn more about some of our projects!
Cellular Basis for Plasticity in the Autonomic Nervous System
The autonomic nervous system controls all those routine automatic functions you seldom think about such as respiration, blood pressure, blood flow, heart rate, gastrointestinal function and hormone secretion. While, some of these have a superimposed cortical control, for the most part they are controlled by feedback mechanisms that function perfectly well without your intervention!
