Neurovascular Physiology Laboratory - Techniques
The unifying theme of the Neurovascular Physiology Laboratory’s research is elucidating the mechanisms of neurovascular dysfunction in adults with pre-clinical cardiovascular disease, with a current emphasis on adults with depression and other mental health disorders. The lab utilizes direct recordings of sympathetic neural activity coupled with mechanistic examinations of vascular function. This integrative and translational approach allows for comprehensive investigations of neurovascular function and dysfunction in humans.
Assessment of Sympathetic Neural Function: Microneurography
This technique is used to obtain direct recordings from the sympathetic nervous system. Microneurography involves the insertion of a very small microelectrode into a peripheral nerve, most commonly the peroneal nerve of the lower leg.
Our lab utilizes this technique to investigate muscle sympathetic nerve activity (above) at rest and during acute ‘stressors’ (e.g., handgrip exercise, mental arithmetic, intravenous infusions), as well as skin sympathetic nerve activity during thermoregulatory challenges (e.g., whole-body heating or cooling).
Assessment of Microvascular Function: Intradermal Microdialysis
This technique involves the placement of small semi-permeable microdialysis fibers in the outer layers of the skin. Micromolar concentrations of vasoactive pharmacological agents are administered to the cutaneous microcirculation through these fibers. Intradermal microdialysis is coupled with laser Doppler flowmetry to continuously measure blood flow in the microvasculature surrounding each microdialysis site.
This is a minimally invasive approach that allows for the targeted pharmaco-dissection of the molecular mediators of vascular function that is not otherwise possible in humans. Additionally, effluent from each microdialysis fiber can be collected and substances of interest can be measured. Finally, we also can take small biopsy samples of skin and perform biochemical and molecular analyses of these tissue samples in order to more fully understand the physiological regulation of microvascular function.