Cyclic Glycine-Proline Improves Memory and Reduces Amyloid Plaque Load in APP/PS1 Transgenic Mouse Model of Alzheimer’s Disease

Figure 1

cGP improves memory in APP/PS1 mice. cGP treatment was given to wild-type (WT) and APP/PS1 mice. (a) Escape latency during the 8 days of training and during the long-term memory (LTM) test ( in all groups). There were significant differences in escape latency between APP/PS1 mice and WT mice day 4 onwards during the course of training and also during the LTM test. cGP-treated APP/PS1 (cGP-APP/PS1) mice showed significantly reduced escape latency compared to APP/PS1 mice day 4 onwards during the training and during the LTM test. Escape latencies of WT mice and cGP-treated wild-type (cGP-WT) mice were similar throughout the training and during the LTM test. (b) Time spent in different quadrants during the probe trial (LTM test in (a)). APP/PS1 mice spent significantly less amount of time in platform quadrant (Q4) than the WT mice. cGP-APP/PS1 mice spent significantly more time in the platform quadrant compared to untreated APP/PS1 mice. cGP-WT mice and WT mice spent similar amount of time in the platform quadrant. (c) Number of annulus crossings during the probe trial (LTM test in (a)). APP/PS1 mice displayed significantly reduced number of annulus crossings compared to WT mice. cGP-APP/PS1 mice showed significantly increased number of annulus crossings compared to untreated APP/PS1 mice. WT mice and cGP-WT mice showed similar number of annulus crossings. (d) The representative track plots during the probe trial (LTM test in (a)). Asterisks denote significant difference () between the WT and APP/PS1 groups, and # denotes significant difference between the APP/PS1 and cGP-APP/PS1 groups.

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