Caffeine and diphenyl diselenide improve long-term memory impaired in middle-aged rats

The aim of the present study was to evaluate the effects of diphenyl diselenide (PhSe)(2) supplemented diet (10 ppm) associated to the administration of caffeine (15 mg/kg; i.g.) for 30 days on the novel object recognition memory in middle-aged rats. The present findings showed that (PhSe)(2)-supplemented diet enhanced short-term memory, but not long-term memory, of middle-aged rats in the novel object recognition task. The (PhSe)(2) supplemented diet associated with caffeine administration improved long-term memory, but did not alter short-term memory, impaired in middle-aged rats. Daily caffeine administration to middle-aged rats had no effect on the memory tasks. Diet supplemented with (PhSe)(2) plus caffeine administration increased the number of crossings and rearings reduced in middle-aged rats. Caffeine administration plus (PhSe)(2) diets were effective in increasing the number of rearings and crossings, respectively, in middle-aged rats, [H-3] glutamate uptake was reduced in hippocampal slices of rats from (PhSe)(2) and caffeine plus (PhSe)(2) groups. In addition, animals supplemented with (PhSe)(2) showed an increase in the pCREB/CREB ratio whereas pAkt/Akt ratio was not modified. These results suggest that the effects of (PhSe)(2) on the short-term memory may be related to its ability to decrease the uptake of glutamate, influencing the increase of CREB phosphorylation. (PhSe)(2)-supplemented diet associated to the administration of caffeine improved long-term memory impaired in middle-aged rats, an effect independent of CREB and Akt phosphorylation. (C) 2014 Elsevier Inc. All rights reserved.