Probing Brain’s Depth, Trying to Aid Memory | NYTimes

By Benedict Carey

PHILADELPHIA — The man in the hospital bed was playing video games on a laptop, absorbed and relaxed despite the bustle of scientists on all sides and the electrodes threaded through his skull and deep into his brain.

The man, Ralph, a health care worker who asked that his last name be omitted for privacy, has severe epilepsy; and the operation to find the source of his seizures had provided researchers an exquisite opportunity to study the biology of memory.

The Department of Defense on Tuesday announced a $40 million investment in what has become the fastest-moving branch of neuroscience: direct brain recording. Two centers, one at the University of Pennsylvania and the other at the University of California, Los Angeles, won contracts to develop brain implants for memory deficits.

Their aim is to develop new treatments for traumatic brain injury, the signature wound of the wars in Iraq and in Afghanistan. Its most devastating symptom is the blunting of memory and reasoning. Scientists have found in preliminary studies that they can sharpen some kinds of memory by directly recording, and stimulating, circuits deep in the brain.

Unlike brain imaging, direct brain recording allows scientists to conduct experiments while listening to the brain’s internal dialogue in real time, using epilepsy patients like Ralph or people with Parkinson’s disease as active collaborators.

The technique has provided the clearest picture yet of how neural circuits function, and raised hopes of new therapies for depression and anxiety as well as cognitive problems. But experts also worry about the possible side effects of directly tampering with memory.

“A decade ago, only a handful of centers had the expertise to perform such real-time experiments in the context of first-rate surgery,” said Michael Kahana, a neuroscientist at the University of Pennsylvania and the recipient of one of the new contracts granted by the Defense Advanced Research Projects Agency, or Darpa. “Today, there are dozens of them, and more on the way; this area is suddenly hot.”

Ralph was edgy on the way to the hospital. He knew that the “diagnostic evaluation” his doctor here at Thomas Jefferson University had recommended was no quick office procedure. It was a fishing expedition of sorts — in the depths of his own brain.

Epilepsy is one of medicine’s great mysteries. The seizures that characterize the disorder are caused by electrical storms in the brain that are as hard to predict as squalls on the open sea. They can erupt early in life, for reasons that may be partly genetic, and they are common after head injuries. But scientists cannot identify an exact cause.

What they do know is that many patients’ brains have a “hot spot” where the seizures originate — and that removing that pinch of tissue can reduce the symptoms, often drastically. The challenge: finding that spot in each person.

Since the 1950s, surgeons worked by instinct and experience, stimulating points on the brain’s surface, guided by the patient. Yet in people like Ralph, they need not only to map the brain’s surface but to sound its depths. They made punctures in the top of his skull and threaded 11 probes deep into his medial temporal lobes, near an area called the hippocampus, about level with the ear.

That wait can take two to three weeks, and surgeons are using this period to study patients who are awake and responsive with electrodes smack dab in areas of the brain that are most important for learning and memory.

The hippocampus is the very seat of memory formation, and its importance emerged from the study of an epilepsy patient whose procedure went famously awry. Henry Molaison, known worldwide as H.M., had severe seizures until a surgeon removed the hippocampus from both hemispheres of his brain in 1953. In a series of experiments, Brenda Milner of the Montreal Neurological Institute and McGill University showed that, without those seahorse-shaped organs, H.M. could form no new memories for facts, figures or faces. This finding, the most important in modern brain science, opened the way for direct-recording experiments.

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My comment on the Times site:

Rima NYT Comment SmallAs the parent of a teen with Autism and intractable Epilepsy that is treated through a very restricted diet and a Vagal Nerve Stimulator implant (VNS), I am very grateful to the volunteers and doctors involved in this research. While her current treatment has been successful, it is difficult to implement.

Maybe one day, thanks to them, she and others in her situation will be able to decide whether or not to undergo treatment that will end the need to treat her epilepsy as it is being treated now.


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