Green tea polyphenols ameliorate ethanol-induced spatial learning and memory impairments by enhancing hippocampus NMDAR1 expression and CREB activity in rats.

The current research probed into the effects of green tea polyphenols (GTPs) on ethanol-induced spatial learning and memory impairments and inquired the potential molecular mechanism in rats. Thirty 8-week-old male Sprague-Dawley rats were randomly divided into three groups. The control group (control, n=10), ethanol group (ethanol, n=10), and GTPs intervention group (GTP, n=10) received gavage administration of saline, ethanol, and ethanol-GTP solution, respectively, for 8 weeks. Morris water maze was applied to assess the spatial learning and memory function of rats in each group at the last week of treatment. There was no dramatic change in body weight of rats in the different groups. Compared with rats in the control group, 8-week ethanol gavaged rats showed increased escape latency period and decreased time in the target quadrant. Moreover, 8-week ethanol gavage decreased the density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region. In contrast, GTP intervention decreased escape latency period and increased the time in the target quadrant, the density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region. The current findings indicated that GTP intervention can improve ethanol-induced spatial learning and memory impairments in rats after ethanol withdrawal, which is related to the upregulated density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region.