Effects of halothane on feeding motor activity in the snail Lymnaea stagnalis

Snails exposed to the general anaesthetic halothane show an increase in biting plus mouthing movements. Perfusion of the isolated CNS with halothane leads to a period of increased spiking activity, followed by suppression of activity in identified feeding motoneurones in the buccal ganglia. Synaptic inputs to motoneurones from interneurones of the buccal feeding pattern generator are differentially affected. Possible mechanisms underlying the generation of motoneuronal bursting in the presence of halothane are examined.