Fig. 11.

Effects of LLI on functional improvements against Aβ toxicity as measured in Barnes maze task and novel object recognition test. (A) The Barnes maze task was performed to test the spatial learning and memory ability of the indicated animals. Representative escaping traces of normal control rats (a) and rats at day 14 after infusion with Aβ (b: without LLI; c: with LLI) are shown in the up panel. The escape latency to find the black hidden box at day 12, 13, and 14 after Aβ infusion is shown in (d). Escape velocity was recorded, and statistical data are shown in (e). (B) Probe trials in the Barnes maze task were performed on day 15 and 18 after Aβ infusion, 1 day and 4 days after the last maze trials, respectively. Representative traces are presented from probe trials on day 15 (a–c) and day 18 (d–f) for the indicated animals in each group. Relative radial-quadrant occupancy (the time spent in the target radial-quadrant) was recorded and statistically analyzed. Note that Aβ-treated animals with LLI spent significantly less time to find the escape box (A, a–d) and more time in the target radial-quadrant (B, a–g) than LLI-untreated Aβ animals. (C) Five-minute novel object recognition tests at 17 and 18 days after Aβ infusion were performed to monitor the long-term recognition memory (a). Representative traces of the indicated groups to explore the familiar object and a novel object on day 18 are shown (b–d). The time spent exploring each object and the discrimination index percentage were analyzed (e and f). All the data are expressed as means ± standard error from 7 to 8 animals in each group. ^*p < 0.05 versus control group or between groups (C: e), ^#p <0.05 versus LLI-untreated Aβ group. Abbreviations: Aβ, beta amyloid; LLI, low-level laser irradiation.