GM1 ganglioside treatment promotes recovery of electrically-stimulated [3H]dopamine release in striatal slices from rats lesioned with kainic acid

Ganglioside GM1 and the Central Nervous System

GM1 is one of the major glycosphingolipids (GSLs) on the cell surface in the central nervous system (CNS). Its expression level, distribution pattern, and lipid composition are dependent upon cell and tissue type, developmental stage, and disease state, which suggests a potentially broad spectrum of functions of GM1 in various neurological and neuropathological processes. The major focus of this review is the roles that GM1 plays in the development and activities of brains, such as cell differentiation, neuritogenesis, neuroregeneration, signal transducing, memory, and cognition, as well as the molecular basis and mechanisms for these functions. Overall, GM1 is protective for the CNS. Additionally, this review has also examined the relationships between GM1 and neurological disorders, such as Alzheimer's disease, Parkinson's disease, GM1 gangliosidosis, Huntington's disease, epilepsy and seizure, amyotrophic lateral sclerosis, depression, alcohol dependence, etc., and the functional roles and therapeutic applications of GM1 in these disorders. Finally, current obstacles that hinder more in-depth investigations and understanding of GM1 and the future directions in this field are discussed.

Evaluation of the mechanisms underlying the kainate-induced impairment of [3H]dopamine release in the rat striatum

Kainic acid caused a marked decrease of the electrically evoked release of [3H]dopamine from rat striatal slices 4 days after its injection (10 nmol/microliters) into the corpus striatum. This damage was prevented by the non-N-methyl-D-aspartate (non-NMDA) receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) when co-injected with kainic acid into the striatum. Prior systemic administration of the NMDA selective antagonists (cis-4-phosphonomethyl-2-piperidine carboxylic acid (CGS 19755), dizocilpine (MK-801) and ketamine did not alter the kainate effect. Previous destruction of the cortico-striatal pathway abolished the kainate-induced decrease of [3H]dopamine release. When injected into the striatum, domoic acid or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) mimicked kainic acid and damaged the dopaminergic nigro-striatal afferents. The [3H]dopamine release evoked by electrical stimulation of slices of frontal cortex was unaffected following local injections of kainic acid. Taken together, the results indicate that AMPA/kainate receptors play a key role in the impairment of [3H]dopamine release caused by kainate in the striatum. However, the kainic acid effect is probably indirect since it appears to require the availability of endogenous glutamate originating from cortico-striatal afferents.