Effects of acute administration of betaine on LPS-induced memory impairment in the Y-maze test. The Y-maze test was carried out 7 days after LPS (30 μg/mouse, i.c.v.) injection. The mice were treated with betaine (0.163 mmol/kg, s.c.) 1 hr before or 1 hr after LPS injection. Y-maze data (A: % alternation, B: total arm entries) are shown as the median (vertical column) and the first and third quartile values (vertical line). The number of mice used is shown in parentheses. Significance levels: *p < 0.05 vs. sham control (Mann-Whitney's U-test), #p < 0.05 vs. LPS alone (Mann-Whitney's U-test).