A team at the Institute of Science Tokyo has developed a drug candidate that may extend the period during which motor functions lost due to a stroke can be recovered, currently limited to about two months, by suppressing a type of protein.

People who lose the ability to speak or to move their hands or feet after the death of nerve cells in the brain due to a cerebral infarction can regain these functions to a certain extent through rehabilitation.

This recovery is possible because surviving nerve cells repair the neuron networks, with microglia — cells in charge of brain immunity — helping the restoration process by secreting a protein called insulin-like growth factor 1 (IGF1).

Takashi Shichita, a professor at the institute's Medical Research Laboratory, and other members of the team conducted research on mice involving genetic manipulation. The team discovered that microglia stopped secreting IGF1 after a while following a stroke due to the function of another protein, ZFP384.…