Discovery of new brain passage may help predict Alzheimer’s early

WASHINGTON - For decades, scientists have struggled to locate the tiny passage, which is believed to deteriorate gradually as part of normal aging and far more quickly due to Alzheimer’s disease. Now, UC Irvine researchers have identified for the first time in humans a long-hidden part of the brain called the perforant path.

“The nice thing about this is we may be able to predict Alzheimer’s very early,” said Craig Stark, UCI associate professor of neurobiology and behavior.

That’s what prompted Diana Burns of Anaheim to participate in the study.

In late 2008, when she forgot yet again where she’d put her purse, and then couldn’t remember why she was in the laundry room, Burns decided she had to know: Was she, like her aging mother, going to be a victim of the debilitating loss of brain function known as Alzheimer’s disease?

“When you’re a caregiver for somebody with Alzheimer’s, you always wonder if it’s going to happen to you,” said Burns, who had quit her job to stay home the day her mother was found unconscious and bleeding half a mile from their house, with no idea how she got there. “I was becoming concerned because I myself was forgetting things, so I thought, ‘Now is the time to find out.’”

Burns, 64, searched online for human clinical trials and found UCI’s Center for the Neurobiology of Learning and Memory. Soon Stark, the center’s interim director, and his staff had her ensconced in their big MRI machine.

The UCI researchers developed and used a new ultrahigh-resolution technique to electronically peer through dense matter near the brain’s hippocampus in search of the perforant path.

The passageway is basically a bundle of nerve fibers, lined up like straws, connecting a region called the entorhinal cortex to the seahorse-shaped hippocampus.

By monitoring the brains of Burns and others via their ultrahigh-resolution technique - know as diffusion tensor imaging - the UCI team was able to detect water molecules moving in the exact area where they knew the passage had to be.

The scientists then painstakingly tracked the progress of the molecules along the length of the fiber bundle, thereby identifying the perforant path.

The UCI team is now examining people with mild cognitive impairment - often the first stage of Alzheimer’s. They expect to see far faster deterioration of the perforant path. Such a finding could aid the testing of new medicines.

The study has been published June 28 in the Proceedings of the National Academy of Sciences. (ANI)