February 10, 2012
Brain Stimulation Could Boost Memory In Alzheimer’s Patients
Neuroscientists at UCLA have found a way to help improve a human's memory by stimulating a part of the brain.
The research, published in the New England Journal of Medicine, could lead to a new method for boosting memory in Alzheimer's patients.The team focused on a brain site known as the entorhinal cortex during their study, which is an area considered to be the doorway to an area that helps form and store memories.
"The entorhinal cortex is the golden gate to the brain's memory mainframe," senior author Dr. Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at UCLA, said in a press release. "Every visual and sensory experience that we eventually commit to memory funnels through that doorway to the hippocampus. Our brain cells must send signals through this hub in order to form memories that we can later consciously recall."
The researchers followed seven epilepsy patients who had electrodes implanted in their brains to help pinpoint the origin of their seizures.
They monitored the electrodes to record neuron activity as memories were being formed in the patients' brains.
They then tested whether deep-brain stimulation of the entorhinal cortex or the hippocampus altered recall.
Using a video game featuring a taxi cab, patients played the role of cab drivers who picked up passengers and travelled across town.
"When we stimulated the nerve fibers in the patients' entorhinal cortex during learning, they later recognized landmarks and navigated the routes more quickly," Fried said in a press release. "They even learned to take shortcuts, reflecting improved spatial memory.
"Critically, it was the stimulation at the gateway into the hippocampus — and not the hippocampus itself — that proved effective," he added.
He said the use of stimulation during the learning phase suggests that patients do not need to undergo continuous stimulation to boost their memory, but only when they are learning something important.
This technique may lead the way to neuro-prosthetic devices that can switch on during specific stages of information processing or daily tasks.
"Our preliminary results provide evidence supporting a possible mechanism for enhancing memory, particularly as people age or suffer from early dementia," Fried said in a press release. "At the same time, we studied a small sample of patients, so our results should be interpreted with caution."
Future studies will determine whether deep-brain stimulation enhances other types of recall, like verbal and autobiographical memories.
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