RESEARCH TECHNIQUES

The Cardiovascular Psychophysiology Laboratory utilizes an innovative approach that combines techniques across the clinical-to-translational spectrum: ecological momentary assessment- and daily diary-based approaches to measure stress, behavioral, and cognitive processes in everyday life; ex vivo and in vitro assessments of physiological function; direct in vivo measures of sympathetic neural activity; the in vivo pharmacological dissection of the signaling pathways mediating vascular function; and clinical trials testing therapeutic interventions. This integrative and translational approach allows for comprehensive investigations of cardiovascular function and dysfunction in humans.

Assessment of Daily Stress Processes and Real-World Cognitive Function

We assess multiple dynamic aspects of daily stress processes and real-world cognitive function for 14 consecutive days on a mobile app. Using the framework established by our investigative team, this high-resolution phenotyping approach allows for the precise intra-individual quantification of emotional responsivity to daily stressors as they occur in everyday life across a continuum of stressor exposure and responsiveness. Concurrently, we obtain frequent daily ‘snapshots’ (i.e., 4 assessments per day) of multiple clinically relevant dimensions of both subjective (self-report) and objective (performance-based) cognitive function. This approach is situated within the Mobile Monitoring of Cognitive Change (M2C2) infrastructure (U2CAG060408) and is a reliable, accurate, sensitive, and ecologically valid approach to detect everyday difficulties in cognitive function in complex real-world environments.

Assessment of Microvascular Endothelial Health

The assessment of microvascular endothelial health involves the placement of small semi-permeable microdialysis fibers in the outer layers of the skin (intradermal microdialysis). 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 fiber. This is a minimally invasive approach that allows for the targeted pharmaco-dissection of the molecular mediators of vascular function. 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 or venous endothelial cells and perform biochemical and molecular analyses of these tissue samples in order to more fully understand the physiological regulation of microvascular function.

Assessment of Sympathetic Control of Cardiovascular Function

Our laboratory uses microneurography to obtain direct recordings from the sympathetic nervous system. This technique involves the insertion of a very small microelectrode into a peripheral nerve, most commonly the peroneal nerve of the lower leg. We can utilize this technique to investigate both muscle sympathetic nerve activity at rest and during experimental manipulations (e.g., exercise, cognitive challenges, intravenous infusions), as well as skin sympathetic nerve activity during thermoregulatory challenges (e.g., whole-body heating or cooling).