Fig. 2.

Optogenetic stimulation of excitatory neurons either increases swallow amplitude (Vglut2) or alters swallowing–breathing coordination (Sst). (A) Representative trace of control swallow (blue) and water swallow induced during Vglut2 stimulation (orange). Bar graph showing a significant increase in swallow-related hypoglossal and vagus amplitude, with each dot representing one animal cycle (mean ± SD, P = 0.03, P = 0.03, n = 10). (B) Representative trace of control swallow (blue) and water swallow induced during Sst stimulation (pink). The violin plot demonstrates swallow occurrence significantly later in the respiratory cycle. The dark dotted line depicts the average time a swallow occurs in relation to peak diaphragm activity (mean ± SD, P = 0.001, n = 7), with no change in interburst interval (P = 0.09) or inspiratory delay (P = 0.74) (as defined in Fig. 6).