New role discovered for brain nucleus

HOUSTON, Sept. 24 (UPI) -- U.S. researchers who intensively studied a woman with an unusual brain lesion have discovered a new role for an important area of the brain's thalamus.

The ventrolateral nucleus of the thalamus -- an area long known as being critical for movement -- has now been discovered to play a role in the reorganization of sensory neurons after a brain injury.

Researchers led by Tony Ro of Rice University studied a woman for six years after she experienced an unusual type of stroke that damaged only her brain's right ventrolateral nucleus, leaving the corresponding left nucleus unaffected.

Immediately after her stroke, the woman reported sensory changes, such as decreased sensations on her left side, but was otherwise normal. However, during the subsequent six years she developed highly unusual sensory experiences called synesthesias, in which stimuli cause unusual sensations. For example, the woman reported tingling feelings when she heard certain sounds.

The researchers believe the synesthesia might have been the result of neural reorganization following the stroke.

The study that also included Alessandro Farne, Ruth Johnson, Van Wedeen, Zili Chu, Zhiyue Wang, Jill Hunter and Michael Beauchamp appears in the current issue of the journal Annals of Neurology.

Copyright 2007 by United Press International

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