Pre-infusion of MPEP or CID755673 prevented impairments of spatial memory induced by DHPG infusion.

<p>Bar graphs in <b>A</b>, <b>B</b>, <b>C</b> and <b>D</b> show the summary data (mean ± SEM) of the averaged swimming speed, latency, and percentage values of the swim distance and time in the goal quadrant versus the total swimming distance and time of rats in the MWM test. Bar graphs in <b>E</b> and <b>F</b> show the summary data (mean ± SEM) of the percentage values of the swimming time spent in the goal quadrant, and the number of times crossing the location of the platform in the probe test. Rats received two infusions of chemicals through implanted cannulas in the bilateral CA1 areas as indicated. The second infusion was conducted 10 min after the completion of the first one. The MWM test was performed 5 min after the second infusion. ACSF+ACSF: receiving two infusions of ACSF; ACSF+DHPG: receiving infusions of ACSF followed by DHPG (50 μmol); ACSF+CID: receiving infusions of ACSF followed by CID755673 (182 nmol); MPEP+DHPG: receiving infusions of MPEP (10 μmol) followed by DHPG (50 μmol); CID+DHPG: receiving infusions of CID755673 (182 nmol) followed by DHPG (50 μmol). **: <i>p</i> < 0.01, ****: <i>p</i> < 0.0001 (paired <i>t</i>-test) in comparison with that before the pre-infusion; #: <i>p</i> < 0.05, ###: <i>p</i> < 0.0001 (unpaired <i>t</i>-test) in comparison with rats received ACSF+ACSF. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195095#pone.0195095.s004" target="_blank">S3 Table</a> for statistical details; Values in brackets indicate number of animals tested.