ABSTRACT
AIM: To study the effects of huperzine A on disruption of spatial memory induced by scopolamine (a muscarinic antagonist) and muscimol (a GABAA agonist) in passive avoidance task. METHODS: One-trial passive avoidance task was used to investigate the effects of huperzine A. The avoidance rate was used to evaluate memory retention. RESULTS: Both scopolamine (100 ng) and muscimol (50 ng), injected intracranially 5 min before training, resulted in a decreased avoidance rate. Huperzine A (25 ng), injected intracranially 15 min before training, reversed memory deficits induced by scopolamine and muscimol at 30 min after training, and this reversal persisted at least 1 h. The improving effects of huperzine A exhibited a bell-shaped dose-response curve. CONCLUSION: Huperzine A improved the process of memory formation not only by acting as a highly potent and selective inhibitor of AChE, but also by antagonizing effects mediated through the GABAA receptor.
Subject(s)
Amnesia/drug therapy , Avoidance Learning/drug effects , Cholinesterase Inhibitors/pharmacology , Retention, Psychology/drug effects , Sesquiterpenes/pharmacology , Alkaloids , Amnesia/chemically induced , Animals , Chickens , GABA Agonists , Male , Muscarinic Antagonists , Muscimol , Scopolamine/antagonists & inhibitorsABSTRACT
During the early developmental period of central nerves system, glucocorticoid can influence the activity of hypothalamic-pituitary-adrenocortical axis via glucocorticoid receptors, and modulate the process of neural survival, outgrowth and programming death process; In adult, glucocorticoid can regulate the expression of the factors which correlate with the plasticity of neurons; In aged individual, glucocorticoid can be harmful to nerves under most conditions. Therefore, glucocorticoid plays an important role in the development of neural system.