Effect of SPAR AS infusion on memory retention after water maze acquisition. (A) After training for three consecutive days in the water maze, animals received an infusion of PBS (n=10), SPAR AS (n=13), or MS (n=11) on day 4, followed by probe tests on days 6 and 7. (B) In the two blocks of the third training day, the escape latencies for animals to find the platform were similar in all three groups before infusion. (C) SPAR knockdown mice spent less time around the former location of the platform during the probe tests compared with controls. (D) There was no significant difference in the performance of the visual acuity test in all three groups. (E) Representative swim paths during a 60-s probe test carried out with the animals are shown in (C). ΔP<0.05; *** P<0.001. AS, antisense; MS, missense.