Behavioural tests. Histograms of behavioural tests in the control group and three groups of hydrocephalic rats. a: Vertical movements measured as number of open field rearings, b: horizontal movements measured as number of open field transitions, c: forelimb muscular strength measured in the forelimb grip strength test as the length of time the rats remain suspended and d: learning and memory in the Morris water maze (MWM). Movements and forelimb strength were gradually reduced as ventricular size increased. For the MWM, the time to reach the platform was tested before and after the rats had been through the training program. Learning was impaired in hydrocephalic rats. * p<0.05, ** p<0.01, *** p<0.001 vs control. Data are means ± SEM.