Figure 5. Effects of clonidine treatment during novel object recognition (NOR) memory test in mice.

A, Recognition Index. The CLO-treated group (CLO) presents no increase in the Recognition Index [T_B/(T_A+T_B)] for the short-term retention test (STM) and the long-term one (LTM), compared with the increase normally observed in control subjects. B, Total contacts with both objects. The CLO-treated group presents, during the training session (T), a significantly reduced object exploration. There is no reduction of object exploration in the short-term memory test for this group, but there is for the long-term memory test. C, Escape attempt. During training and short-term memory tests, the CLO-treated group presents almost no tendency to escape as compared with controls. This activity is increased in the long-term memory test, but results are significantly reduced as compared with the control group. Results are presented as means±S.E.M. The statistically significant difference between the two groups is represented by the symbol *, while the symbol # is used to compare the different tests—short- and long-term retention—with training. N = 40∶40.