It is the overall goal of the lab to understand the physiology of sympathetic nervous system activation in the regulation of the acute 'fight or flight' sympatho-adrenal stress reflex and the sympathetic control of cardiovascular funciton.
Chromaffin cells of the adrenal medulla are a primary neuroendocrine output of the sympathetic nervous system. We are determining the secretory behavior of the chromaffin cells under both basal sympathetic tone as well as under the acute sympathetic stress response. Our lab focuses on the manner in which chromaffin cells release different classes of transmitter under physiological stimulation. These studies take place on several different levels. We study the manner in which the sympathetic nervous system excites chromaffin cells at the splanchnic/adreno synapse and how this innervation and excitation functions under varied sympathetic activity levels. We also study the downstream effects of excitation in the chromaffin cells themselves with an emphasis on how chromaffin cells achieve activity-dependent differential release of different classes of neurotransmitters. Major techniques utilized in these studies include electrophysiology, electrochemistry, quantitative imaging and protein chemistry.
In another line of investigation, we are developing a toolkit for the rapid, in vivo mesaure of myocardial and vascular norepinephrine and peptide transmitters under sympathetic activation in healty and diseased hearts. We utilize electrochemical approaches to provide highly localized, high time resolution specific readouts for epinephrine, norepinephrine, neuropeptide Y, vasoactive intestinal peptide and other peptide transmitters. In collaboration with the UCLA Cardia Arrythmia Center, we are deploying these technologies in a beating prcine heart model and are transitioning to human studies in the near future.