Figure 3-4275.

Respiratory analysis of Pbx3-deficient mice. A: Spontaneous inspiratory activity of newborn mice. Plethysmographic recordings correspond to spontaneous inspiration in Pbx3^−/−, Pbx3^+/− and wt littermates, respectively. B: Amplitude histograms of tidal volume (VT) in different genotypes calculated from recording data shown in A. The number of respiratory cycles measured were 144 (Pbx3^−/−), 196 (Pbx3^+/−) and 192 (wt). C: C4 ventral root inspiratory activity in medulla-spinal cord preparations of newborn mice. Faster sweep representations are shown on the right for parts denoted by bars on the left. D: Membrane potential recordings of an inspiratory neuron in the ventrolateral medulla of a Pbx3^−/− mouse. Top tracing, membrane potential trajectory from an inspiratory neuron recorded using conventional whole-cell patch-clamp method; bottom tracing, simultaneous recording of C4 ventral root inspiratory activity. Coordinate patterns are seen in which inspiratory bursts with short duration are followed by a subsequent large burst of long duration followed by apnea.