Published on November 9, 2012 at 1:44 AM
In the test after two hours there was no significant difference between participants who had taken Levodopa and those who had consumed a placebo. However, after six hours memory performance changed. Test subjects with Levodopa recognised up to 20 per cent more photos than the members of the comparison group. The ratio between the amount of Levodopa taken and the body weight of the test subjects proved to be decisive for an optimal dose. "This confirms our assumption that dopamine contributes to anchoring memories in the brain on a permanent basis. You might say it improves the survival chances of memory content," D-zel indicates. "Our study also shows that the survival of memories can be regulated, regardless of how strong these were originally encoded. This is a new finding."
But why did the effect emerge only after six hours? D-zel sees the cause in the way in which the brain stores memories. "When memories are encoded, certain changes take place at the nerve endings, the so-called synapses," he explains. "This activation is however only temporary, and afterwards the state of synapses change back again. This is unless dopamine is available so that newly formed synapses can be stabilised over a long period of time." The test after two hours must still have taken place during the period of short-term synaptic activation, according to the neuroscientist. Both test subject groups therefore had similarly good results. However, at the later time the memories of the test participants with the placebo had already started to fade. Now, the influence of the dopamine was noticeable for the other test subjects.
In this study participants had taken the dopamine precursor before memorizing. The finding that the persistence of memories can be influenced - independent of whether memory encoding was weak or strong - might open the way to further investigation. "It is conceivable that participants might receive the supplement at a later stage," D-zel says. "The idea is that they learn something, then take dopamine afterwards and still don't forget what they have learnt."
In addition, the study gives food for thought for the treatment of Alzheimer's dementia. "The episodic memory suffers substantially when affected by Alzheimer's. Our results show that in addition to current forms of treatment, which chiefly target certain protein deposits in the brain, other aspects should also be taken into consideration", D-zel says. "Here dopamine and the so-called neuromodulatory systems, which release chemical messengers into the brain are of particular importance. But so far, research into this topic is still in its infancy."
Source: Helmholtz Association of German Research Centres