Fig. 2.

Chronic fluoxetine (FLX), but not exercise, reverses spatial learning and memory in poststroke depression (PSD) mice. Spatial learning and memory were tested in the PSD mice treated with vehicle (PSD), FLX (PSD/FLX), or running wheel (RW) vs sham control (sham ctrl), with fixed wheel or vehicle as controls, using the Morris water maze (MWM; timeline, as in Fig. 1A). (A) Acquisition: the latency to reach the hidden platform was measured each test day. Compared with sham, the PSD and PSD/RW mice showed a nearly complete inability to locate the platform with the 60-s test, whereas the PSD/FLX mice showed a significantly reduced latency to reach the platform from days 2 to 10, which was reduced compared with sham from days 2 to 4, suggesting enhanced spatial learning. (B) Probe test tracking: the search strategy taken by single mouse per experimental group in the probe test [arrow indicates the correct (upper) quadrant]. (C) Probe test. Compared with sham, PSD mice showed reduced duration in the target quadrant, and this was reversed in the PSD/FLX group but not in the PSD/RW mice. Data represent mean ± SEM in n = 8 per group, *p <0.05, **p <0.01, ***p <0.001 vs. day 1, ^p <0.05, ^^p <0.01, ^^^p <0.001 vs sham ctrl