Evidence for medullary projections of the intercostal nerve-elicited inspiratory termination

This study hypothesized that the ICN-elicited inspiratory termination reflex required synaptic activation in two distinct regions of the ventral respiratory group (VRG): (1) transitional (tVRG), and (2) pre-Botzinger complex (pre-BotC). Data from adult cats indicate that axons of passage associated with the ICN-elicited termination reflex traverse tVRG, but that relevant synaptic processing does not occur in this region. Furthermore, data indicate that neither synaptic nor axonal transmission within the pre-BotC is required for the SLN- or ICN-elicted termination reflex. (C) 1999 Elsevier Science B.V. All rights reserved.