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Medicine: Worms, Men & Memory

3 minute read

The research subjects ranged from cannibalistic flatworms to elderly patients in a Canadian psychiatric hospital. But both the psychiatrists and the flatworm fanciers were working with the same basic stuff: ribonucleic acid (RNA), which seems to be the chemical paper that carries the imprint of animal and human memories. Learned reports on the widely varied projects last week contained startling but strangely similar suggestions for the future. Some day, said the worm workers, students may be able to take their lessons in tablet form. Some day, said the psychiatrists, an old man’s failing memory may be rejuvenated in much the same way.

A Boost from Yeast. Dr. D. Ewen Cameron, imaginative and resourceful head of Montreal’s famed Allan Memorial Institute, was impressed by the fact that as his patients grew older, the amount of RNA in their cells decreased. Although the plausible theory that the imprint of memory is reflected in changes in RNA molecules (TIME, Feb. 10, 1961) has not yet been proved, Dr. Cameron wondered whether patients with memory defects might be helped by booster doses of RNA.

Human RNA was not available, so Dr. Cameron settled for a similar chemical: RNA extracted from a yeast. Repeated massive, intravenous doses gave the patients stomach upsets and cramps, which required additional medical treatment. But patients suffering from hardening of the brain’s arteries and a group classed as presenile showed marked improvement in their memory of recent events. More advanced cases (listed as senile) got no better, Dr. Cameron told the Society of Biological Psychiatry, but he and his researchers are encouraged. They are working on ways to reduce RNA’s undesirable side effects and are trying a tablet form. Because his investigations called for far more liberties than can be taken with human subjects, the University of Michigan’s Psychologist James V. McConnell, 36, turned to flatworms (Planaria), regarded as the most primitive creatures capable of true “learning.” In 150 to 250 lessons, the worms learned that the flashing on of an electric light meant that they should contract and brace themselves for an electric shock. With this Pavlovian conditional reflex, high-IQ flatworms heeded the light warning and contracted 23 times out of 25.

From Tail to Head. When a flatworm is cut into two or more pieces, each piece grows into a whole new flatworm. Dr. McConnell and colleagues found that the cut-off part of an educated flatworm passes on much of its learning to the whole worm into which it grows. More surprising, the tails showed as much memory retention as the heads—often more.

This suggested a chemical change, and Dr. McConnell reasoned that it ought to be possible to educate preschool flatworms by feeding them the proper memory chemicals. He and Assistant Barbara Humphries chopped up some well-trained worms and fed the pieces by hand to unschooled animals. The cannibals learned by eating: when they went to light-and-shock school, they proved to be flatworm prodigies; they learned twice as fast as cannibal worms fed on uneducated meat.

McConnell and colleagues are now try ing to extract RNA and capture the flat-worm’s tail-end chemical memory. They feel sure that if they succeed, some enterprising drug company will be able to synthesize the modified RNA. “If transfer of memory should be valid for man as well as worm,” said Dr. McConnell as he indulged in a flight of fancy at a San Francisco conference, “why should we waste all the knowledge a distinguished professor has accumulated, simply be cause he’s reached retirement age?”

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