Figure 14. The antagonism of glycine receptors in the pFRG attenuated the inhibitory effect of BötC stimulation on the active expiratory pattern in control rats.

Panel A: raw and integrated (∫) recordings of cervical vagus (cVN), abdominal (AbN) and phrenic (PN) nerve activities of a control in situ preparation, representative from the group, before and after bilateral microinjections of strychnine (1 mM) in the pFRG. Note the generation of active expiration (AbN late-E bursts) after disinhibition of pFRG. Panel B: recordings of cVN, AbN and PN of a control in situ preparation, illustrating the respiratory responses to unilateral L-glutamate microinjection (10 mM) in the BötC (arrow) after the antagonism of glycine receptors in the pFRG. Panels C-G: average values of PN burst frequency and amplitude, cVN post-I and AbN E2 activities, and AbN late-E frequency, respectively, under baseline conditions, after strychnine microinjections in the pFRG and after L-glutamate microinjections in the BötC of control in situ preparations (n=9). * different from baseline, # - different from strychnine in the pFRG, P<0.05 (RM one-way ANOVA followed by Bonferroni’s post-hoc test). Panel H: coronal sections of brainstem from a control in situ preparation, illustrating the sites of bilateral microinjections in the pFRG (red) and unilateral microinjection in the BötC (green). The injection sites in each area of each animal of the group are represented as the grey area in the schematic drawings on the right.