Neurology

Projects

• Identification of the link between glutamate and nitric oxide in transmission of cardiovascular reflex signals in the brain stem. These studies test the hypothesis that glutamate transmission is critically linked to synthesis of nitric oxide by local cardiovascuneurons in the brain stem but that transduction of signals by ionotropic glutamate receptors differs from that by metabotropic receptors.
• Identification of the role played by preganglionic parasympathetic neurons of the pontine superior salivatory nucleus in cerebrovascular control. These studies have already established for the first time that arterial baroreflexes may modulate cerebral circulation through direct projections from the nucleus tractus solitarii, where baroreceptor nerves terminate, to the superior salivatory nucleus. We now seek to test the hypothesis that the baroreceptor projections to the pons use glutamate as an excitatory transmitter and to determine how this pathway participates in protecting the brain from damage caused by ischemia.
• Identification of the role played by the substance P receptor in cardiovascular reflex transmission by neurons in the nucleus tractus solitarii. We have shown that selective destruction of neurons that express the substance P receptor alters baroreflex transmission but also leads to cardiac changes and sudden death in some treated animals. The cardiac changes in these animals in many ways mirror those seen in humans after subarachnoid hemorrhage.
• In summary the projects have potentially important bearing on stroke, hypertension, and sudden death and could lead to novel therapies based on their pharmacological findings.