ORIGINS OF EXCITATORY DRIVE WITHIN THE RESPIRATORY NETWORK - ANATOMICAL LOCALIZATION

THIS study identified several sources of excitatory drive within the r at brain stem respiratory network. Excitatory neuronal projections to the ventral respiratory group (the largest brain stem respiratory neur on population in the rat) were identified by selective retrograde labe ling with tritiated aspartate. Neurons were labeled within portions of the nucleus of the tractus solitarius, the region of the ventral resp iratory group, superficial to the facial nucleus, the medullary raphe nuclei and the parabrachial/Kolliker-Fuse nuclei. These findings are t he first anatomical demonstration of sources of excitatory drive withi n the respiratory network, and are consistent with electrophysiologica l data localizing a source of excitatory drive within the pre-Botzinge r complex subdivision of the ventral respiratory group.