Fig. 5.

(A) Rythmic respiratory motor bursts from left and right XII roots during fluid flow in a microfluidic chamber. (B) Time-dependent changes in burst frequency and amplitude are small under these conditions. (C) Standard solution flowing simultaneously over separate halves of the brain slice allowed simultaneous bursts to be recorded on both XII nerve roots. Fig. 5A and C display similar configurations with different time scales to distinguish separate experiments. (D) Superfusion of the right half of the slice with Na⁺-free solution showed that rhythmic XII activity was blocked on the right half while XII activity could be recorded on the left half, thereby showing that the slice microenvironment can be selectively altered. (E) Distilled solution containing concentrated fluorescent dye was used in conjunction with a standard solution to verify flow over the 650 μm brain slice in a microfluidic chamber. The two solutions maintained equal flows ranging from 0.5 to 1 ml min^-1, thereby exposing the two halves of the brain slice to different environments. * = P < 0.05.