Figure 4.

Boundaries necessary for rhythm and activity patterns in 3 mm [K⁺] of 700-μm-thick slices with unilaterally exposed preBötC. A, Plot of the longevity of rhythms versus boundaries of 10 c+preBötC[700/−0.42]W-P1/4 slices and 12 r+preBötC[700/−0.58]S-D/W-P0/4 slices. The preBötC extension necessary for rhythm is possibly <100 μm as indicated by the pink box framing brainstem tissue common to the rhythmic slices of both types. The dashed box underneath A indicates the boundaries of nonrhythmic slices. The squares next to the longevity scale bar show the mean longevity (±SEM) of rhythms in the 10 c+preBötC[700] (blue square) and the 12 r+preBötC[700] (purple square) slices, whereas the black square shows the longevity of rhythm in 7 m-preBötC[700/-0.89]W-P1/3 slices (see supplemental material, available at www.jneurosci.org as supplemental material). B, The top panel shows eupneic bursts of regular rate and amplitude in the c+preBötC[700/−0.40]W-P2 slice of Figure 1B. After the occurrence of in vitro apnea ∼2 min after the recording in the second panel from the top, consecutive bath application of TRH (third panel) and (after washout of TRH) NK1 receptor agonist GR73632 (bottom panel) reactivated a eupnea and a eupnea–sigh burst pattern, respectively. C, The top panel shows large sigh bursts and eupneic bursts of smaller and variable amplitude in the r+preBötC[700/−0.65]W-P1 slice of Figure 1B. After in vitro apnea, occurring ∼3 min after the recording in second panel from the top, TRH induced a eupnea burst pattern (third panel), whereas GR73632 initiated a eupnea–sigh pattern very similar to that in control (bottom panel).