Effects of subacute administration of betaine on LPS-induced memory impairment. Y-maze and novel object recognition tests were carried out 7 and 10-12 days after LPS injection (30 μg/mouse, i.c.v.), respectively. Mice were treated with betaine (0.163 mmol/kg, s.c.) 1 hr before and 1 and 24 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 novel object recognition data (C: familiarization session, D: retention session) are shown as the median (horizontal bar) and the first and third quartile values (vertical column). The number of mice used is shown in parentheses. Significance levels: **p < 0.01 vs. sham control, #p < 0.05, ##p < 0.01 vs. LPS alone (Mann-Whitney's U-test).