CVL

Newsroom

  • The Center mourns the loss of a dear friend and tireless CVL supporter. click here

  • CVL councilmember and benefactor’s life remembered in the Dallas Morning News.click here

  • Aging-themed issue of Nautilus Magazine explores cognitive benefits of learning a new game such as chess, cites CVL.click here

  • ‘Fitizen’ group at the Jewish Community Center of Dallas learns about research at CVL. click here

  • CVL research published in JoN finds that some memories persist in the face of strong interference. click here

  • Dr. Sara Festini’s research probes busyness levels and cognitive performance.click here

international University down arrow

CVl Annual Review


CVl Annual Review

Charting Our Progress is CVL’s annual review, with archives available

here
Logo cvl Logo dallas

Study Probes Amyloid Accumulation & Aberrant Hippocampal Activity

zhuangsongheadshot

DALLAS – August 24, 2016 – The hippocampus is part of the brain that plays a major role in the memory of objects, space and events in general. Damage and impaired function in the hippocampus is a key sign of Alzheimer’s Disease.

A recent study has found that amyloid proteins associated with Alzheimer’s Disease can be found in the brains of healthy adults and that the presence of amyloid is associated with lowered evoked activity in the hippocampus when new memories are formed.

Interestingly, the decreased activity was observed in adults aged 60 to 74 but not in the oldest adults aged 75 to 89. These findings were reported in a recently published paper by Dr. Zhuang Song and colleagues at UT Dallas’ Center for Vital Longevity.

The combination of amyloid plaque accumulation and aberrant hippocampal activity could be a strong indicator of pre-clinical Alzheimer’s, Dr. Song said. The more neocortical amyloid plaques, the less detectable task-evoked activity there was in the hippocampus – where another major Alzheimer’s pathology, namely tau tangles, likely forms in adjacent medial temporal regions as amyloid begins depositing on the outer, grey matter areas of the brain.

The findings were reported online in the most recent edition of NeuroImage: Clinical.

A number of neuroimaging studies have investigated this possible relationship in early Alzheimer’s, however, past findings have been mixed, particularly because of the relatively subtle and hard-to-measure fMRI signal of typical task-evoked hippocampal activity in humans.

Taking on these technical challenges, this study is the first to look critically at age as a variable (among the elderly) that may influence how brain amyloid deposition is related to hippocampal activity in an incidental memory encoding task. “Age has usually been considered a ‘nuisance’ variable in previous studies of older adults,” Dr. Song said. “Age hasn’t been factored into studies in a meticulous way and our study is an attempt to change that.”

The study sample consisted of 82 cognitively normal elderly participants aged 60 to 89 years who participated in CVL’s Dallas Lifespan Brain Study, and underwent a battery of cognitive tests, as well as fMRI and PET scanning. All participants undertook an incidental memory-encoding task during an event-related fMRI scan, during which participants viewed pictures of outdoor scenes that were compared to baseline readings obtained while staring at a fixation cross on a screen.

“We found an interaction between cortical amyloid deposition and age, even among the elderly, and that the effects of amyloid on hippocampal activity can be measured,” Dr. Song said. “These effects may lead to memory impairment later in life, as the disease progresses.”

The other study authors are Drs. Ian M. McDonough, now at the Univ. of Alabama, Peiying Liu, Hanzhang Lu, both at Johns Hopkins University, and Denise C. Park, Director of the Dallas Lifespan Brain Study. Dr. Song is a research scientist, working on this project at the Center for Vital Longevity.

The research was supported by the National Institutes of Health, as well as Avid Radiopharmaceuticals, a division of Eli Lilly.

– Alex Lyda