Impairments of spatial memory induced by bilateral infusions of DHPG (50 μmol) into the CA1 area.

<p><b>A</b> shows swimming track plots of a rat in the MWM performance test in a training session at day 1 (left) and day 5 before (middle) and after (right) the infusion of DHPG (50 μmol) into the bilateral CA1 areas, respectively. Arrow indicates the intra-CA1 infusion of DHPG. Stars indicate where the rat was put into the pool; white circles indicate the position of a platform in the third quadrant (Q3, the goal quadrant) and 2 cm below the water level. Black squares indicate the final locations of the rat. The summary data (mean ± SEM) of the latency from when rats were released into the pool to reaching the platform, the averaged swimming speed, the percentages of swimming distance and time within the goal quadrant relative to the total swimming distance and time are shown in <b>B</b>, <b>C</b>, <b>D</b> and <b>E</b>, respectively. Open triangles indicate the performance of non-operated rats. Arrows indicate the infusion of ACSF (open circles) or DHPG (filled circles) into the bilateral CA1 areas. *: <i>p</i> < 0.05, **: <i>p</i> < 0.01. ***: <i>p</i> < 0.001, ****: <i>p</i> < 0.0001 (paired <i>t</i>-test) in comparisons with that before the infusion at day 5 in the ACSF or DHPG group, or with that of the first performance of MWM at day 5 in non-operated rats; #: <i>p</i> < 0.05, ##: <i>p</i> < 0.01, ####: <i>p</i> < 0.0001 (Bonferroni post hoc test in repeated measures two-way ANOVA) in comparison with those of the non-operated group; $: <i>p</i> < 0.05, $ $: <i>p</i> < 0.01, $ $ $: <i>p</i> < 0.001, $ $ $ $: <i>p</i> < 0.0001 (Bonferroni post hoc test in repeated measures two-way ANOVA) in comparison with those of the ACSF group. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195095#pone.0195095.s002" target="_blank">S1 Table</a> for statistical details; Values in the brackets indicate the number of rats tested.