Neuregulin expression after focal stroke in the rat.

Upregulation of neuregulin has been demonstrated in traumatic brain injury, but a role for neuregulin in ischemic brain injury has not been investigated. Therefore, we used a rat permanent middle cerebral artery occlusion model to examine the distribution of neuregulin after the onset of ischemic stroke. We found an increase in immunohistochemical staining for neuregulin in the penumbral regions of the cortex. The increase in neuregulin appeared to be neuronal. There was no neuregulin co-localization with astrocytes or macrophages. These results demonstrate that neuregulin is induced in neurons following ischemic stroke and may be involved in neuroprotection and repair.