Forming New Memories
According to scientists at the University of Sheffield in the UK, their studies demonstrate that neurons that give off the neurotransmitter dopamine deep inside the brain may be some of the first brain cells to malfunction when Alzheimer’s disease begins.1 Although known as a factor in Parkinson’s disease, dopamine has not been a focus of dementia research until now. This is new, and it looks to be important. The Sheffield scientists think that when dopamine-producing cells start to go wrong, the part of the brain that organizes the formation of new memories becomes less effective and goes on the blink. They add that focusing on these dopamine-releasing cells could potentially “revolutionize” testing for early Alzheimer’s. It could also change the way brain scans are performed and analyzed. The Sheffield analyses involved 3 Tesla magnetic resonance imaging (MRI) brain scans (more powerful than ordinary MRI scans) performed on people whose brains were in different states of cognitive decline. Some had mild cognitive impairment (MCI) while other participants suffered with full-blown Alzheimer’s disease. The scientists then compared these scans to those of people whose brains performed normally.Main Memory Center Needs Dopamine
The tests show that a small section of the brain known as the ventral tegmental area has to produce the right amount of dopamine to enable the hippocampus – an important memory center – to lay down new memories. According to researcher Annalena Venneri, when the supply of dopamine drops, the hippocampus “will not work efficiently. The (study) results point at a change which happens very early on, which might trigger Alzheimer’s disease.” Dr. Venneri says that focusing on these dopamine-producing neurons “could potentially lead to a new way of screening the elderly population for early signs of Alzheimer's disease, changing the way brain scans are acquired and interpreted and using different memory tests. Another possible benefit is that it might lead to a different treatment option with the potential to change or halt the course of the disease very early, before major symptoms manifest.”Remember Better with Dopamine
At the same time, research at Cedars Sinai in Los Angeles shows that dopamine neurons play a central part in forming episodic memory – the memory involved in recalling things like where you parked the car last night and what you had for dinner yesterday. When these types of neurons in a part of the brain called the substania nigra lose their function it leads to Parkinson’s disease.2 This study supports what the researchers at Sheffield are finding, that dopamine plays a more important role in memory than scientists used to think. "Dopamine neurons degrade in neurodegenerative diseases such as Parkinson's, which in addition to motor symptoms is often also accompanied by cognitive issues such as memory problems," says researcher Ueli Rutishauser. And while these types of studies are revealing the importance of dopamine for memory, investigations at the University of Pennsylvania suggests that compounds found in Indian snakeroot, a plant used in traditional Indian medicine for thousands of years for fever, stomach aches, dysentery, malaria, paranoia and schizophrenia,3 may be useful for promoting better dopamine function in the brain. This research shows that snakeroot contains a substance called ajmalicine that influences mitochondria (organelles that produce energy in neurons and other cells) in ways that can help benefit dopamine activity.4 As this is written, it is too soon to confirm whether snakeroot is a safe and effective supplement. It’s important to remember that all of this cutting-edge research is so new right now, no scientist who wants to keep his job will say it’s ready for prime time -- or even predict when it will be. But I have a strong feeling we’re going to see some more impressive progress related to dopamine in the near future. And it might be a game changer.