The role of hippocampal (CA1) NMDA receptor on learning and memory in presence and absence of zinc chloride in adult male rats

Introduction: Zinc is an essential trace element that plays an important role in synaptic plasticity and modulating the activity of CNS and involve in learning and memory. Synaptic vesicle zinc in the hippocampus area exerting modulatory effects on NMDA glutamate receptor. Method: In this experiment the effects of NMDA agonist and antagonist administration intra hippocampus on passive avoidance learning and memory in adult male rats in presence and absence of Zncl2 by step down task has been investigated. Animal divided into 10 group (n=8).Control group, second group received 0.1µg/rat NMDA in 1µlit saline for 4 days. Sham group received saline in the same volume. Forth group received 1µg/rat MK-801 in 1µlit saline 10min before training for 4 days. Sham group received saline in the same volume. Five remain groups received 30mg/kg/day zncl2 in drinking water for 2 weeks. Sixth groups only received 30mg/kg/day zncl2, but others groups (7, 8, 9, and 10) in addition consumption zncl2 received drug and saline in the same condition to 2,3,4,5 groups. Result: our experiment showed that consumption of 30mg/kg/day zncl2 impair learning and memory in adult male rats (P<0.05), while administration of NMDA improve the impairment effects on zncl2 consumption (P<0.05), but administration of MK-801 increasing the impairment effects of zncl2. Concultion: It seems that zinc impaired passive avoidance learning and memory by effects on subunits of NMDA receptor in hippocampus.