Researchers at Stanford and at the Pierre and Marie Curie University in France had targeted neurons in the mouse brain's cortex and thalamus known to be overactive during seizures.

WSJ: Scientists Cast Light Onto Roots of Illness Deep in the Brain

Medications that relax the bladder can be effective for relieving symptoms of overactive bladder and reducing episodes of urge incontinence.

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If children also have a genetic predisposition to an overactive immune system, they could be at higher risk for cancer.

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It might be able to selectively turn off brain cells that are overactive, as in epilepsy.

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