On the other hand, their studies show that high levels of alcohol decrease the ability of new brain cells to develop and mature. This can instead cause an impairment of memory except at times of heightened emotion, when memory is increased.
The study carried out by researchers Dr Maggie Kalev and Professor Matthew During was published in the Journal of Neuroscience.
"Low levels of alcohol promoted neutral memories, such as remembering objects," says Dr Kalev of the Faculty of Medical and Health Sciences. "However, contrary to popular belief, we also found that excessive levels of alcohol enhanced memories of highly emotional stimuli, meaning the concept of "drinking to forget" is unlikely to be true.
"Our work suggests that heavy drinking actually reinforces negative memories", she added.
The study was also able to pin down the mechanism by which low doses of alcohol improve memory. A very important brain receptor, called NMDA receptor is needed for this process. When rats that did not produce sufficient NMDA receptors were given alcohol, memory improvements were not observed. On the other hand, rats with increased numbers of NMDA receptors mimicked effects of low dose alcohol.
The authors were quoted: "Pathways by which memory is laid down are unclear, but NMDA receptor is critical in this process. Building on this knowledge may help in the treatment of memory disorders, such as Alzheimer's disease and other dementias. Furthermore, it could assist in designing novel strategies to enhance brain functions in other disease contexts."