Figure 8.
Disruption of rhythmic respiratory activity by block/attenuation of GABAAergic and glycinergic inhibition in the BötC of in situ perfused brainstem–spinal cord preparations. A, B, Two examples from experiments using different preparations illustrating perturbations caused by microinjections of gabazine and strychnine (30 µm slowly injected during the period indicated by the brown bars at the top and blue rectangles). As in the vivo experiments, respiratory frequency was reduced by a prolonged TE, integrated phrenic nerve discharge amplitude (∫PN) was also reduced, and ultimately apnea occurred. Simultaneously recorded integrated cVN (∫cVN) in A shows disruption of rhythmic activity and tonic discharge (shift of integrated activity baseline) during apneic period. B, Simultaneously recorded integrated pre-BötC pre-I/I population activity from another experiment also reflects the reduction of inspiratory frequency and termination of rhythmic activity during bilateral microinjections of the inhibitory receptor blockers in BötC.