Figure 5.

Hypoglossus motor output is normal in KCC2a^–/– mutants at P0. A, Left: Schematic representation of an isolated medullary preparation containing both the pFRG (red shading) and preBötC (orange shading) networks with macroelectrodes placed on ventral rootlets to record rhythmic respiratory activity from the phrenic (C4) and hypoglossal (XII) nerves simultaneously. Right: Synchronized activity (indicated by dashed vertical lines) seen in integrated traces recorded from C4 (Int C4, bottom trace) and hypoglossal (Int XII, top trace) nerves in a KCC2a^–/– preparation at P0. B, Cross-correlation histogram showing perfect 1:1 synchronized bursting in the C4 and the XII rootlets of 7 different mutant preparations. The complete absence of any skipped cycles at the level of the hypoglossal root indicated that apneas observed in vivo are not due to a dysfunction of the upper airways motor command.