Neural control of breathing, central pattern generation, sensorimotor integration, plasticity
Research is directed toward the elucidation of central nervous system mechanisms responsible for the generation and modulation of rhythmic breathing efforts. Electrophysiological, neuroanatomical and molecular approaches are used to elucidate the neural circuitry and synaptic mechanisms underlying the control of this centrally generated motor behavior. In vivo and in vitro studies are designed to identify the neural basis of respiratory rhythm generation and the afferent pathways modifying this rhythm. An additional goal is to understand the neural basis for adaptation in respiratory motor control. Changes in breathing such as occur during development or which may occur in response to injury or disease require adaptation in the central pathways controlling breathing. Experiments are underway to identify: a) the neural pathways generating respiratory rhythm and controlling specific respiratory reflexes, b) cellular and network mechanisms giving rise to time-dependent (plastic) changes in respiratory motor output , and c) synaptic drives and cellular properties underlying the control of spinal respiratory motoneuron activity.
Figure Legend. Morphology and membrane potential patterns of in vivo filled respiratory neurons in the ventrolateral medulla. Expiratory (top electrophysiological trace) and inspiratory (bottom trace) neurons are divided into subgroups based on discharge pattern and axonal trajectories. Physiological activation of lung stretch receptors, paucisynaptically activates distinct groups of expiratory neurons, thereby prolonging their period of discharge and the duration of expiration. (Cover illustration, J. Neurosci. 16: 6526-6536, 1996 see Hayashi, F., J. Neurosci. 16: 6526-6536, 1996)