Fig. 2

Effect of THP on learning and memory in SD rats after 6 months of treatment. a Three- and 9-month-old rats were tested in the MWM. b THP/NS effects on MWM platform acquisition measured by escape latency (in seconds). The effect on platform escape latency was measured for 7 days at the beginning of every month over 6 months of MWM testing. c THP/NS effect on swimming speed when searching for the MWM platform. d THP/NS effect on number of platform crosses during the three-probe trial time period after MWM acquisition. e THP/NS effect on time spent in the MWM platform quadrant during the three-probe trial time period after MWM acquisition. The THP (0.5 mg/kg) group spent significantly more time in the MWM platform quadrant. For this and subsequent analyses, histogram values represent mean ± SD (n = 10). *P < 0.05, **P < 0.01, ***P < 0.001