Stimulating key junctions in brain strengthens memory, says researchers

New Delhi, Feb 9: Memory in human patients can be improved by stimulating certain key junctions in the brain, a new research report conducted at University of California, Los Angeles (UCLA) states this.

According to neuroscientists at UCLA who conducted this research over on the seven epilepsy patients who already had electrodes implanted in their brains to pinpoint the origin of their seizures, ‘when the nerve fibers in the patients' entorhinal cortex are stimulated during learning they later recognized landmarks and navigated the routes more quickly’.

This new finding can pave the way for new methods of strengthening memory in patients in the early stage of Alzheimer's disease, researchers believe.

A research team of neurologists and neurosurgens led by Dr. Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at UCLA stated, ‘during their study, the UCLA team studied a brain site called the entorhinal cortex. Entorhinal cortex is instrumental in converting day-to-day experiences into lasting memories.’

The team also focused on the entrance to the hippocampus, which plays a role in forming and storing memories.

"The entorhinal cortex is the golden gate to the brain's memory mainframe," said Dr. Itzhak Fried.

"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," he added.

For this study the researchers used a video game consisting a taxicab, virtual passengers and a cyber city. And the patients were asked to play the role of cab drivers, who had to pick passengers and drive across town to deliver them to one of six requested shops.

The team monitored the electrodes to record neuron activity while memories were being formed. The team observed whether deep-brain stimulation of the entorhinal cortex or the hippocampus changed recall.

"When we stimulated the nerve fibers in the patients' entorhinal cortex during learning, they later recognized landmarks and navigated the routes more quickly," Dr. Fried said.

"They even learned to take shortcuts, reflecting improved spatial memory,” he said.

"Critically, it was the stimulation at the gateway into the hippocampus - and not the hippocampus itself - that proved effective," he said further.

Fried said that the use of stimulation only in the learning phase indicates that incessant stimulation is not required to boost the memory and it is only needed while learning new things.

This finding can facilitate the way to neuro-prosthetic devices that can be switched-on during specific stages of information processing or daily tasks.

"Losing our ability to remember recent events and form new memories is one of the most dreaded afflictions of the human condition," research team leader said.

"Our preliminary results provide evidence supporting a possible mechanism for enhancing memory, particularly as people age or suffer from early dementia. At the same time, we studied a small sample of patients, so our results should be interpreted with caution," he added.

The report is scheduled to publish February 09th edition of New England Journal of Medicine.

--With inputs from ANI