Photothrombotic infarct impairs experience-dependent plasticity in neighboring cortex.

Spontaneous restorative plasticity is reported frequently after stroke. To test whether conditions in perinfarct cortex facilitate plastic changes, we examined experience-dependent plasticity of cortical functional representation of vibrissae in rat brain after focal photothrombotic stroke. Cortical activation was visualized with [C]2-deoxyglucose. To induce plasticity, four rows of whiskers were trimmed on one side of the snout for a month, whereas one row was spared. This deprivation was started immediately after the stroke. In control rats, cortical representation of the spared row whiskers was significantly enlarged compared with undeprived controls. In rats with infarct posterior to the barrel cortex, no plastic change of the spared row representation was observed. We conclude that early after stroke, use-dependent plasticity is impaired in the perinfarct cortex.