The present invention relates to biologically active peptides derived from the neurite outgrowth-promoting domain of laminin-1, i.e. the .gamma.1-chain of laminin-1. These peptides include the decapeptide RDIAEIIKDI (SEQ ID NO: 1) and the truncated peptides derived therefrom comprising the biologically active domain thereof, the tripeptide KDI. The invention is directed to the biologically active tripeptide motif KDI, and to its use in promoting regeneration of neuronal or non-neuronal tissues and, in specific, to its use in the treatment of spinal cord injuries.