Increased synaptic plasticity in the surround of visual cortex lesions in rats

Lesion-induced functional loss is reduced when new synaptic connections are established in the surround of a cortical lesion. For this, long-term synaptic plasticity can play a key role. We studied long-term potentiation (LTP) and long-term depression (LTD) in slices of rat visual cortex with small cortical lesions. Surprisingly, the normal balance between LTP and LTD was significantly altered in the first week following cortical injury. Theta-burst induced LTP was increased, whereas LTD evoked by low frequency stimulation was not affected. The increased potentiation of subcortical inputs after cortical lesions opens a window for facilitated early functional reorganization by repetitive visual training.