Fig. 6. Comparison of halothane's effect on inspiratory (current study) and expiratory (previous publication 3) premotor neurons. The significance of the anesthetic effect on control frequency (ΔFcon ), overall excitation (ΔFe ), overall inhibition (Δα), and postsynaptic receptor response (Δρ) versus no change is indicated within the bars . *P < 0.05; **P < 0.01; ***P < 0.001. The anesthetic effect on the different variables was not significantly different between inspiratory and expiratory neurons (not significant [n.s.]).