protective effect of α-terpineol against impairment of hippocampal synaptic plasticity and spatial memory following transient cerebral ischemia in rats

objective(s): cerebral ischemia is often associated with cognitive impairment. oxidative stress has a crucial role in the memory deficit following ischemia/reperfusion injury. α-terpineol is a monoterpenoid with anti-inflammatory and antioxidant effects. this study was carried out to investigate the effect of α-terpineol against memory impairment following cerebral ischemia in rats. materials and methods: cerebral ischemia was induced by transient bilateral common carotid artery occlusion in male wistar rats. the rats were allocated to sham, ischemia, and α-terpineol-treated groups. α-terpineol was given at doses of 50, 100, and 200 mg/kg, ip once daily for 7 days post ischemia. morris water maze (mwm) test was used to assess spatial memory and in vivo extracellular recording of long-term potentiation (ltp) in the hippocampal dentate gyrus was carried out to evaluate synaptic plasticity. malondialdehyde (mda) was measured to assess the extent of lipid peroxidation in the hippocampus. results: in mwm test, α-terpineol (100 mg/kg, ip) significantly decreased the escape latency during training trials (p<0.01). in addition, α-terpineol increased the number of crossings over the platform location and decreased average proximity to the target in probe trial (p<0.05). in electrophysiological recording, α-terpineol (100 mg/kg) facilitated the induction of ltp in the hippocampus which was persistent over 2 hr. α-terpineol (100 and 200 mg/kg) also significantly lowered hippocampal mda levels in rats subjected to cerebral ischemia. conclusion: these findings indicate that α-terpineol improves cerebral ischemia-related memory impairment in rats through the facilitation of ltp and suppression of lipid peroxidation in the hippocampus.