Effects of dietary supplementation of certain nutrients on maze performance and biochemical indices in mice after exposure to high +Gz.

Objective: To explore the possible effects of nutritional supplements on brain function as reflected by Water Maze test performance in mice after +Gz exposure.

Method: Mice were arranged into control group (group A), +Gz group without nutritional supplementation (group B) and +Gz plus nutritional supplementation group (group C). Each group contains 12 mice. Mice in group A were not exposed to +Gz while mice in both group B and group C were exposed to 8 min + 10 Gz. Distilled water was gavaged to group B mice 3 h before +Gz exposure. On the day before +Gz exposure pyridoxol fortified water was given and 3 h before exposure mixed amino acids solution were gavaged to group C mice. Water Maze test was done and scores were recorded in all groups. After the Water Maze test was completed, blood was collected through the eyes for serum amino acid determinations and brain tissue was collected by decollation for monoamine determination and gamma-glutamyl transferase (GGT) activity evaluation.

Result: After +Gz exposure, longer completion time and more mistakes were observed in Water Maze test in group B as compared with group A and a trend of improvement in group C was noticed. The ratio of brain 5-HT to dopamine (DA) was significantly reduced in group C as compared with group B. Gamma glutamyl transferase (GGT) activity in brain tissue in group C and group B increased significantly.

Conclusion: High sustained +Gz exposure significantly reduces Water Maze test performance in mice (longer completion time and more mistakes). It seems that there is a trend of improvement in Water Maze performance in mice in dietary nutritional supplementation group, which might be due to significant reduction in ratio of brain 5-HT to DA in mice with nutritional supplementation.