Expression of polysialylated neural cell adhesion molecule in rat brain after transient middle cerebral artery occlusion

The highly polysialylated form of neural cell adhesion molecule (PSA-NCAM) is important for neurite outgrowth. With this molecule as a marker of plast ic change in neurons, we investigated its temporal expression in rat brain after transient middle cerebral artery (MCA) occlusion. In sham-control bra in, only subependymal neurons showed a positive immunoreactivity for PSA-NC AM. After 90 min of transient MCA occlusion. neurons in the piriform cortex began to be positively stained at 1 h. while neurons in the cortex and cau date of the MCA territory became positive after 8 h. The stainings persiste d for 1 and 3 days after reperfusion. The present results indicate that neu rons in the cerebral cortex and caudate have the capability of plastic chan ge in the adult brain, and that those in the piriform cortex rapidly underg o plastic change probably in response to transneuronal injury. (C) 2001 Pub lished by Elsevier Science B.V.