Conditioned place avoidance (CPA) in wild-type young (A) and middle-aged (B) zebrafish.

<div><p>Y-axis: % time spent in the red zone of the test tank at Baseline (BL), during Conditioning and Extinction phases of the study.</p> <p>Conditioning phase: * p<0.00001 for main group and training day effects; no significant difference between age groups.</p> <p>Extinction phase: between group comparison: p<0.0003, <0.0001 and <0.0001 for day 4, 5 and 6, respectively; within middle-aged group comparison, relative to Baseline, p<0.01, NS and NS for day 4, 5 and 6 respectively; within young group, p<0.0001, NS and <0.02 for day 4, 5 and 6, respectively.</p>