Dr.Alexander (A.J.) Rosenberg, Ph.D.

My research goals are focused on minimizing health disparities in our aging population by conducting high-quality human research on cerebrovascular and cardiovascular physiology and cognitive health. I am interested in how to reduce the risk of cerebrovascular and cardiovascular events through different treatment strategies, such as exercise, diet and lifestyle modifications, antioxidant supplementation, and environmental interventions.

Research Topic 1: Development of a Test for Assessment of Cerebral Vascular Function

The projected outcomes of this investigation include, 1) evidence that cerebral reactive hyperemia is a valid stimulus to assess cerebrovascular reactivity, 2) evidence that detrimental cerebrovascular adaptations occur with aging, and 3) development of a test with potential prognostic/predictive utility for individual risk assessment of a future cerebrovascular event/disease. This information will be of vital importance to the medical community regarding cerebrovascular health in aging individuals and testing the effectiveness of interventions and therapies that may ameliorate these effects.

Research Topic 2: Relationship between Cerebrovascular Regulation and Cognitive Function Following Exercise

This project aims to elucidate the effect of aerobic and resistance exercise training on cognitive function and its relationship to cerebral blood flow regulation, artery stiffness, and blood pressure in healthy adults. Although current literature suggests that habitual lifelong exercise may have profound effects on cognitive function in healthy elderly populations, the effects of exercise on cerebral blood flow regulation and its connection to normal cognitive function in healthy young and elderly adults remain inconclusive. Further investigation for a comprehensive understanding of the relationship between aging, cognition, and cerebrovascular function is essential to the development of a precision approach for targeting cerebrovascular and cardiovascular-related interventions for treating and preventing accelerated cognitive decline with aging.

Techniques and equipment:

• Finger photoplethysmography – (non-invasive blood pressure monitor for continuous arterial pressure, and calculation of stroke volume,        cardiac output, and total peripheral resistance)
• 3-lead electrocardiograph – (for assessment of R-R intervals, heart rate, heart rate variability)
• Transcranial Doppler ultrasound – (for assessment of cerebral blood velocity in the intracranial vessels)
• Duplex Doppler ultrasonography – (for assessment of cardiac function and conduit artery function)
• 24-Hr Ambulatory Blood Pressure Monitoring Device – (for measurement of arterial pressure waveforms to assess central and peripheral arterial stiffness and blood pressure variability)
• Gas analyzer – (for continuous assessment of end-tidal CO₂)
• Finger pulse oximeter – (for assessment of arterial oxygen saturation)
• 16-channel MP160 and Acknowledge – (data acquisition hardware and software)
• Basic cognitive function testing
• Experimental approaches and techniques utilized in the study of human cerebrovascular regulation, including:

             o   Cerebral autoregulation (via oscillatory lower body negative pressure, repeated squat-to-stand, spontaneous transfer function analysis)

             o   Neurovascular coupling

             o   CO₂ Reactivity testing

Use of techniques to induce orthostatic stress to simulate hemorrhage and cerebral hypoperfusion (via lower body negative pressure, squat-to-stand test)