Anesthetics block excitation with various effects on inhibition in MRF neurons.

The effects of isoflurane and halothane on the behavior of mesencephalic reticular neurons in the rat were studied by long-term extracellular microelectrode recording. Both anesthetics always suppressed the excitatory responses with simultaneous blocking or augmenting effects on the inhibitory responses of the reticular neurons. The blocking effects on the inhibitory responses were more frequently noticed during light anesthesia than during the deep stage.