Figure 11.
Effects of the KCC2 blocker furosemide. A, Rectified and integrated suction electrode recordings of C4 ventral roots in a P1 brainstem–spinal cord preparation. The muscimol-induced (Mus) decrease of respiratory rhythm (left) was diminished after 30 min of furosemide application (right). B, Perforated-patch recording of an I neuron (top) and XII nerve root recording (bottom) from a P1 medullary slice preparation. The muscimol-induced membrane depolarization and increase of respiratory rhythm (left) were diminished in the presence of furosemide (right). C, Population data for brainstem–spinal cord and medullary slice preparations showing changes in respiratory frequency relative to control in response to muscimol or muscimol plus furosemide (Fu) administration. D, Summary of Vrest and EGABA-A data from perforated-patch recordings of I neurons in medullary slices (P1–P2) in 3 or 9 mm [K+]o, with and without furosemide. Vrest was not affected by furosemide, but EGABA-A was shifted toward Vrest in both types of postnatal in vitro preparations. *p < 0.05, significant difference between muscimol-induced changes in breathing frequency (C) and EGABA-A (D) with and without furosemide.