THE surprising discovery that the deadly neurological disease Huntington鈥檚 improves ability at some cognitive tests is helping us to understand the illness.
from the Leibniz Research Centre for Working Environment and Human Factors in Dortmund, Germany, and his colleagues asked 13 people with Huntington鈥檚 and 25 apparently healthy controls, half of whom had a gene for Huntington鈥檚 but no symptoms, to judge whether tones played in a series were long or short. Huntington鈥檚 worsens ability at most cognitive tests, but in this one the people with Huntington鈥檚 performed better: they had an average reaction time of 0.5 seconds, compared with 0.64 seconds for the controls. They also made fewer errors (The Journal of Neuroscience, ).
Beste has an idea why this is so. How Huntington鈥檚 damages the brain is a mystery, but one explanation is that neurons become abnormally sensitive to the neurotransmitter glutamate, and eventually die off as a result. As glutamate is vital for sensory discrimination, Beste says this extra sensitivity could explain the improvements his team found. He says the finding strengthens the glutamate theory and suggests the cognitive task be used as a test for drugs that block the glutamate response.
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of the Medical College of Georgia in Augusta says the study shows that drug designers should take care to preserve brain functions that work despite disease.
