Parenteral antioxidant treatment preserves temporal discrimination following intrahippocampal aggregated Aβ_(1-42) injections

There is evidence that oxidative stress may play a role in the neuropathology of Alzheimer's disease (AD). This study used an aggregated beta-amyloid (Aβ) injection model of AD in the rat, and a recycling conjunctive schedule of food reinforcement to examine the effects of bilateral intrahippocampal injections of aggregated Aβ_(1-42) (5.0 μl/side) on temporal discrimination, and the efficacy of the antioxidant α-tocopherol (150 mg/kg daily p.o.) in alleviating these effects. The results indicated that bilateral intrahippocampal injections of aggregated Aβ_(1-42) detrimentally affected temporal discrimination from five-day block 31-35 post-injections until the end of the study (90 days post-injections). Daily treatment with α-tocopherol improved temporal discrimination under the recycling conjunctive schedule following aggregated Aβ_(1-42) injections from the five-day block 61-65 days until the end of the study.