RESEARCH HIGHLIGHTS - CASES OF PLANT-INDUCED ALZHEIMER'S OFFER NEW INSIGHTS INTO THE DISEASE
Parkinson's and Alzheimer's-like diseases are as much a part of the island of Guam as its sandy beaches, emerald sea ... and palm-like trees called cycads. Only recently did scientists discover that the seeds of the cycads, a favorite food of the locals, contain BMAA, a nonprotein amino acid which triggers neurological damages in mammals.
In a joint project with New York University and the University of Cape Town, Dr. Dennis Wm. Stevenson, Director of the Harding & Lieberman Laboratories at The New York Botanical Garden and the world's leading expert on cycads, is currently studying BMAA's mechanism in the brain which causes Parkinson's and Alzheimer's diseases. This study will offer a rare insight into these human neurological disorders which still remain, for the most part, mysteries.
Now endangered, the cycads can boast the title of the living fossils of the plant world, with a 290-million-year lineage which makes them contemporaries of the dinosaurs. But unlike the dinosaurs, the cycads knew how to play the survival game. In an effort to ward off predators, cycads produce diverse carcinogens and BMAA, which blocks the glutamate receptors responsible for neurons' activation in the mammalian brain. This blockage prevents the transfer of information in the brain and results in neurological disorders in mammals and Parkinson's-like diseases or premature Alzheimer's in humans. The incubation period in humans can span decades.
In a related finding, while each cycad species has its own species of pollinating weevil, none of these weevils is harmed by BMAA. Dr. Stevenson's team discovered that BMAA is produced and retained in specialized cells called gold cells because of their color. When pollinating the cycad, the weevils eat the cycad tissue, but their digestive system does not break down the gold cells. Instead, the gold cells are excreted intact as components of the weevils' cocoons, which, with the gold cells built into them, are toxic to weevil predators.
Principal Investigator: Dr. Dennis Wm. Stevenson,
Director, Harding & Lieberman Laboratories
Public Relations:
Annick Sullivan
718-817-8815
Research Highlights is a series of glimpses into the botanical research of NYBG scientists. (11/97)
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