Posts classified under: H

Ronald Harper, Ph.D.


The laboratory examines neural mechanisms underlying sleep state: control of breathing, somatomotor activity, and cardiovascular action in developing and adult small animal preparations. Neural mechanisms are examined through neurophysiologic techniques which include assessment of intrinsic optical changes in neural tissue, functional magnetic resonance imaging, and chronic single neuron recording; the optical imaging and cell recording studies are often combined with microdialysis techniques to determine neurochemical mechanisms underlying cell action. We found that a substantial portion of sleep effects on normal and disordered breathing result from rostral brain influences on pontine and medullary structures, that activity over wide areas of these structures can be visualized during ventilatory and pressor challenges in freely behaving animals, and that immature development of mechanisms controlling descending rostral brain influences on breathing can place the organism at risk.