Linear correlation between peak PSR f
imp and PNA duration (A and C), and between time to peak PSR f
imp and PNA duration (B and D), during PAV before and after lung lavage, and after instillation of surfactant. A and B present recordings from one single-unit receptor (6 breaths per setting) in one cat; C and D present the mean values of recordings from 5 single-unit receptors from 5 cats that completed the entire protocol (one single-unit receptor per cat; see end of Methods). Note the inverse correlation between peak PSR f
imp and PNA duration. For both correlations, p < 0001 (panels A and B) and p < 0.01 (panels C and D) r, correlation coefficient.