Fig. 5. Method used to analyze the effect of halothane on the postsynaptic γ-aminobutyric acid type A receptor response. The graph shows the response to picoejection of muscimol onto the neuron in figure 4. Linear regression analysis was performed with the y-intercept constrained to pass through the neuron control frequency at the zero dose rate. The anesthetic effect in terms of changes in neuronal frequency is illustrated by interpolation of the net decrease at an identical dose rate, e.g. , at 0.02 pmol/min muscimol, from the dose–response curve at 0 minimum alveolar concentration (MAC) (solid line ) and at 1 MAC (dashed line ). Halothane caused an enhancement of the muscimol-induced net decrease from 34.5 to 46.6 Hz.