Figure 6:

A: Pilot study to determine the time course of the change in respiratory rate after bilateral injection of the AMPA receptor antagonist NBQX followed by the NMDA receptor antagonist AP5 into the functionally identified Parabrachial Nucleus (PBN)(n= 12). In all animals, respiratory rate had decreased significantly from the control rate (circle) to the end of the AP5 injection (Time 0 seconds). In most animals, the decrease in respiratory rate plateaued ~3 minutes after the end of the AP5 injection (black line) or continued to further decrease only minimally. B: Representative example from one animal of the increase in inspiratory (TI) and expiratory (TE) duration with bilateral injections of NBQX and AP5, first into the bilateral KF and then into the bilateral PBN. C+D: Changes in TI (left) and TE (right) with each antagonist injection, relative to the maximal value for TI and TE after the last injection. Each color represents one animal. While there is variation between the effect size of each injection, the average (black dotted line) suggest that both receptor subtypes in both areas contribute to phase duration in an additive fashion. B: Injection order PBN, then KF, n=11. C: Injection order KF, then PBN, n=10.