LONDON, (Reuters) -- Scientists in the United States said on Wednesday they had rewired the visual input of young animals to a part of the brain normally used for hearing, demonstrating a versatility of function that might some day lead to treatments for brain damage and blindness.

The researchers connected inputs from the eye to a part of the brain called the auditory cortex to enable ferrets to respond to visual signals.

``What our work demonstrates is the tremendous capacity for vision to be mediated by new areas of the brain,'' Professor Mriganka Sur of the Massachusetts Institute of Technology (MIT) told Reuters in a telephone interview.

``So if there is blindness that is due to loss of the cortex that is visual, in principle but not in practice, other areas of the cortex can take over the function of the visual cortex. That is what our work suggests,'' he added.

Damaged brain cells cannot be repaired or replaced, but the MIT research shows that if brain damage is detected early other cells might be brought into play to fill the gap.

Sur is head of MIT's department of brain and cognitive sciences. His research is limited to animals but he said it is not inconceivable that, many years in the future, rewiring brain circuitry could be used to restore brain functions in humans.

``We are far from understanding how to, at will, direct fibres from the eye which carry visual information to new cortical areas. That has to be resolved. Our work shows that new cortical areas can do new and interesting things,'' he said.

Sur and his colleagues, whose research is reported in the latest edition of the journal Nature, said the auditory cortex of his rewired ferrets interpreted input from the eyes but it didn't do the job as well as the visual cortex would have.

``The brain is a wonder of development that involves molecules, cells and inputs being in the right place at the right time. Connections between cells are the key to brain function. By altering the input to the tissue, the connections changed as a result, and we think the very molecules changed as well,'' Sur explained.

Research has shown that in people who are blind from birth the visual cortex can be used for other functions, such as increased sense of touch for Braille reading or a heightened sense of hearing.

``There is not an intrinsic genetic specification of the cortex to do one and only one thing. Inputs can change the function of the cortex,'' said Sur.

http://dailynews.yahoo.com/htx/nm/20000420/hl/rsa_68.html