Fig. 2. Rate meter recording of the dose response to picoejection of the γ-aminobutyric acid type A (GABAA) antagonist bicuculline. The duration of the picoejection is marked. The neuron frequency at complete GABAAblock is assumed to represent the overall excitatory drive to the neuron (Fe ). The difference between overall excitation and control frequency (Fcon ) relative to Fe represents the prevailing overall inhibitory drive (α= (Fe − Fcon)/Fe). MAC = minimum alveolar concentration.