Ameliorating effects of idebenone and indeloxazine hydrochloride on impairment of radial maze learning in cerebral embolized rats

The ameliorating effects of idebenone and indeloxazine hydrochloride on the impairment of memory and learning were studied in cerebral embolized rats. The embolized rats had impaired memory and learning ability in the radial maze task; these were demonstrated by a decrease in correct responses and an increase in total errors. In particular, the rats showed severe impairment of working memory, as shown by a marked increase in the numbers of re-entries into the arm that had been already visited. Idebenone (30 mg/kg, p.o.) exerted marked ameliorating effects on the impairment in the embolized rats: the drug significantly increased the correct responses and decreased the errors. Indeloxazine hydrochloride also improved the memory impairment in the embolized rats, as shown by a reduction of the errors. The ameliorating effects of these drugs may be due mainly to improvement of hypofunctions of the central nervous system. These results confirm that idebenone and indeloxazine hydrochloride may have ameliorating actions on impairment of memory and learning induced by brain hypofunction, and they suggest that the action of idebenone is more potent than that of indeloxazine hydrochloride.