Word: rna
(lookup in dictionary)
(lookup stats)
Dates: during 1960-1969
Sort By: most recent first
(reverse)
...have on its surface as many as 10,000 points of contact (synaptic knobs) with other neurons (see chart). But by means of exquisitely delicate instrumentation and an electron microscope, Dr. Hydén has discovered that when human neurons are stimulated, some of the millions of ribonucleicacid (RNA) molecules inside them give orders to the glial cells to manufacture new proteins. The nature and pattern of these proteins contain an imprint of something that has been perceived, and may become a part of a memory...
...reaction is more readily observable in animals, Hydén reported. When a normally lefthanded rat was forced to learn to use his right paw to get food out of a tube, cells in the most highly developed part of the brain (the cortex) produced a special kind of RNA as well as proteins. A similar thing happened in goldfish that were forced to learn a new kind of swimming by having buoyant plastic foam stuck under their chins by Dr. Victor Shashoua of M.I.T. Fish that Dr. Shashoua made work just as hard swimming against a current, but without...
...cells, said Hydén, seldom divide and replace themselves as do most other cells in the body. The neurons that a child has at six years must last him a lifetime. As he ages, some of them become damaged or die, so the brain's output of RNA in learning situations is decreased...
Finally, the researchers took reovirus-3, a common cause of respiratory and intestinal infections in man and remark able because its RNA core is normally double-stranded. Unlike the whole vi rus, the purified RNA extracted from it did not cause infections, but it stimulated interferon production within an hour in cells grown in the test tube. The process usually requires five hours with the whole virus...
...species is of little or no use in another, so there was no chance of "growing" it in animals for later use in man. But now it seems virtu ally certain that man can be stimulated to produce it by a periodic intake of a harmless form of RNA, either injected or even more convenient, by means of an inhaler. Though the maximum effect may last only two or three weeks, that would be long enough to protect other members of a family when one of them starts spreading cold germs around the house. And interferon might be still more...