Effects of schwann cell suspension grafts on axon regeneration in subacute and chronic CNS traumatic injuries.

In a previous study, we have shown that microtransplanted Schwann cell suspensions foster structural recovery of the acutely transected postcommissural fornix. The emphasis of the present study was to examine whether subacutely and chronically injured axons also demonstrate significant responsiveness to implanted Schwann cells. Microinjected suspensions of cultured Schwann cells i) elicited a growth response and attracted axons in a subacute and chronic traumatic lesion but ii) failed to stimulate regrowth of the postcommissural fornix projection at any nonacute postlesion stage. In conclusion, the single intervention strategy of Schwann cell microimplantation is not sufficient to ensure regeneration of the subacutally or chronically transected postcommissural fornix. The use of Schwann cells as stimulators of axon regrowth depends on the neuronal cell type and the appropriate postinjury time point. Copyright 1999 Wiley-Liss, Inc.