Scientists may have finally found a drug candidate for reducing the mental retardation caused by Down syndrome. After as little as two weeks on the drug, mice with a genetic impairment similar to the syndrome performed as well as normal animals did on learning tests.
The learning and memory problems characteristic of Down syndrome may occur because its sufferers’ brain cells are unable to form new synaptic connections with neighboring neurons. This inhibition could be the result of overactive GABAA receptors—tiny ion channels on neurons. The drug the researchers tested, pentylenetetrazole (PTZ), interferes with the GABAA receptors, allowing new synapses to be formed at a normal rate.