SPONTANEOUS RECOGNITION OF OBJECT CONFIGURATIONS IN RATS - EFFECTS OFFORNIX LESIONS

The effects of fornix lesions were examined in an object recognition m emory test based on spontaneous exploration. In the standard condition an object (A) was presented in the sample phase and then presented ag ain in the test phase alongside a new object (B). Both fornix-transect ed (Fx) and control (Co) rats spent more time exploring the new object than the familiar object after retention delays of 1 min and 15 min. In two configural conditions designed to test sensitivity to reconfigu red stimuli, the original sample (A) was now either re-presented along side its rearranged version (For All), or the re-arranged version itse lf (For All) was presented with a new object (B). In the first configu ral condition, both the Co and Fx rats spent more time exploring the r econfigured sample (For All) than the original version of the sample ( A) following a delay of 1 min, but not 15 min. In the second configura l condition, both Co and Fx rats spent more time exploring the new obj ect (B) than the reconfigured version of the sample (For All) followin g a delay of 15 min but not 1 min. These present results do not suppor t Sutherland and Rudy's hypothesis on hippocampal function; however, t hey demonstrate that memory of objects as well as memory of reconfigur ed objects could easily be examined in a test based on spontaneous exp loratory behaviour.