Fig. 6.

Dose-related effects of donepezil on performance of a spontaneous novel object recognition task by young Wistar rats. In these experiments, donepezil (or vehicle) was administered by intraperitoneal injection 30 minutes before the training trial. Mean (± S.E.M.) exploration times of the familiar and novel objects after 48-hour delays (A/B retention sessions) are illustrated in the main figure. The inset illustrates the mean (± S.E.M.) discrimination (d2) ratios. d2 ratio = (novel − familiar)/(novel + familiar). ⁺⁺⁺P < 0.001, novel versus familiar object; *P < 0.05 versus vehicle. N = 8–9 for each group.