Figure 5. Phrenic nerve response to ischaemia in situ in the presence of 0.2 μm strychnine or 8 mm[K⁺]_o.

A, recordings of Phr nerve response. Tonic activity was observed during the first minute of ischaemia in most cases. Note the same gasping latency and recovery time to the first incrementing burst (single and double arrows, respectively). B, Phr response to ischaemia of an ethanol-exposed animal in the presence of 8 mm potassium instead of 6.25 mm. Note the absence of increase in frequency and amplitude, the time to first gasp and the very slow recovery. C, increase in Phr nerve frequency (left) was restored in ethanol-exposed animals and the difference between populations was abolished. The increase in burst amplitude (right) was similar between the two populations.