D1 dopamine receptors distribution following photothrombotic stroke in rat cerebral cortex.

The effect of focal photothrombotic stroke on the distribution of D1 dopamine receptor (D1R) sites was examined in different cortical areas of rat brain with quantitative receptor autoradiography using [3H]SCH23390 as a ligand. Unilateral cortical stroke was located in the primary somatosensory cortex. After different survival times (1, 7 and 28 days) D1R binding levels were determined in the lesion core, penumbra, frontoparietal motor (FrPaM) and somatosensory (FrPaSS) areas as well as in homotopic regions in the contralateral hemisphere. One day after stroke, D1R density decreased by 36% (P < 0.01) in the lesion core relative to sham-operated controls. At 7th day binding density was further reduced by 56% (P < 0.002). Twenty-eight days after infarction, D1R binding returned to control level. No alterations in D1R binding levels were found in penumbra and other investigated regions. We suggest that the return of D1R binding to control level in the area initially corresponding to the infarct results from the shrinkage of the lesion volume.