Ethanol and retrograde amnesia : can rats have blackouts and does caffeine help?

The work in this dissertation aims to describe a simple new test for odor-recognition memory in rats that can be readily performed and results in an easily observable and lasting form of memory. This test has allowed for the demonstration of ethanol-induced retrograde memory impairments in rats when ethanol is administered during both the consolidation and reconsolidation phases of memory encoding. The observation that a high-dose of ethanol can cause retrograde memory impairments when administered immediately or within hours after learning has taken place is an original finding that may have implications for understanding human blackouts. Furthermore, the finding that ethanol can disrupt the reconsolidation of a previously consolidated memory has not been previously established. It is also demonstrated that caffeine can prevent ethanol’s memory impairing effects, a result that contributes a new piece of evidence for caffeine’s effects on the learning and memory process. This effect has been further investigated mechanistically and attributed to caffeine’s dual role as a phosphodiesterase type 5 inhibitor and adenosine A2A antagonist. Neither of these mechanisms alone appear to be sufficient enough to prevent the retrograde memory impairments seen with ethanol. It is hoped that this test and our findings will prove useful for future investigations into the effects of ethanol on learning and memory and the human phenomenon of alcohol-induced blackouts.