Parkinson's drug 'helps' the elderly think younger and reap the rewards from the choices they make
As you age you start to lose the
ability to learn from experiencesSo are less
able to predict the chance of getting a reward from choices madeDrug could help the elderly think in a younger mannerResearchers found that older people who took the drug could make decisions in the same way as those in their twenties
Daily Mail Reporter
00:50 GMT, 25 March 2013
08:12 GMT, 25 March 2013
A drug used to treat Parkinson’s Disease could help older people make better decisions, say researchers.
As you get older you begin to lose the ability to learn from experiences, meaning you are less likely to be able to predict the chance of getting a reward from choices made.
This part of the brain, called the nucleus accumbens, is responsible for interpreting the difference between expected reward and actual reward.
As you get older it can be harder to predict the chance of getting a reward with choices you make (stock photo)
These predictors, which come from a brain chemical called dopamine, helps us learn from our actions and in turn make better decisions in the future.
However, a drug widely used on Parkinson’s sufferers could help reverse this process helping older people think as they did when they were younger, according to a new study published in journal Nature Neuroscience.
Dr Rumana Chowdhury, who led the study at the Wellcome Trust Centre for Neuroimaging at University College London, said: 'We know that dopamine decline is part of the normal aging process so we wanted to see whether it had any effect on reward-based decision making.
'We found that when we treated older people who were particularly bad at making decisions with a drug that increases dopamine in the brain, their ability to learn from rewards improved to a level comparable to somebody in their twenties and enabled them to make better decisions.'
Researchers found that the drug helped older people make more rewarding decisions (stock photo)
Researchers used behavioural testing and brain imaging techniques, to investigate the decision-making process in 32 healthy volunteers aged in their early seventies compared with 22 volunteers in their mid-twenties.
Older participants were tested on and off L-DOPA, a drug that increases levels of dopamine in the brain known as Levodopa, widely used to treat Parkinson’s.
The participants were asked to complete a behavioural learning task called the two-arm bandit, which mimics the decisions that gamblers make while playing slot machines. Players were shown two images and had to choose the one that they thought would give them the biggest reward.
Their performance before and after drug treatment was assessed by the amount of money they won in the task.
Dr Chowdhury said: 'Older volunteers who were less able to predict the likelihood of a reward from their decisions, and so performed worst in the task, showed a significant improvement following drug treatment'.
Researchers also looked at brain activity as particpantsn played the game using functional Magnetic Resonance Imaging (MRI).
They measured connections between areas of the brain that are involved in reward prediction using a technique called Diffusor Tensor Imaging (DTI).
The findings reveal that the older adults who performed best in the gambling game before drug treatment had greater integrity of their dopamine pathways. Older adults who performed poorly before drug treatment were not able to adequately signal reward expectation in the brain – this was corrected by L-DOPA and their performance improved on the drug.
Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said: 'This careful investigation into the subtle cognitive changes that take place as we age offers important insights into what may happen at both a functional and anatomical level in older people who have problems with making decisions.
'That the team were able to reverse these changes by manipulating dopamine levels offers the hope of therapeutic approaches that could allow older people to function more effectively in the wider community.'