Modification of memory induced by lidocaine injection after learning in mice (Supplement)

The effect of lidocaine on the contents of brain acetylcholine in mice

Abstract

The present study examined the effects of lidocaine, a local anesthetic, on the central cholinergic system in mouse brain. The mice were killed 5,10,20 and 60 min after the intraperitoneal injection of a non-convulsive dose (40㎎/kg) or a convulsive dose (80㎎/㎏) of lidocaine. The acetylcholine (ACh) contents in the striatum, hippocampus, cerebral cortex and hypothalamus were measured by HPLC-ECD. The ACh contents in the striatum and hippocampus increased 60 min after the injection of the non-convulsive dose of lidocaine. Those in the cerebral cortex increased 20 and 60 min after the injection of the non-convulsive dose of lidocaine. On the other hand, the changes in ACh contents in the striatum, cerebral cortex and hypothalamus after the injection of the convulsive dose of lidocaine showed a time-dependent diphasic pattern: the ACh contents in these brain regions decreased 5 min after the injection of the convulsive dose of lidocaine, and increased 20-60 min after the injection. These findings suggest that lidocaine has an influence on the central cholinergic system.