The invention relates to novel peptides, polypeptides or proteins which specifically bind to cells of the brain and/or the spinal cord. The peptides, polypeptides or proteins can be part of a viral capsid, and they can be used for guiding a recombinant viral vector selectively to the brain and/or spinal cord after systemic administration to a subject, where it provides for a tissue-specific expression of one or more transgenes. The invention therefore also relates to a recombinant viral vector, preferably an AAV vector, comprising a capsid containing at least one of the peptides, polypeptides or proteins of the invention and at least one transgene which is packaged within the capsid. The viral vector is particularly suitable for the therapeutic treatment of a disease or functional disorder of the brain and/or the spinal cord. The invention further relates to cells and pharmaceutical compositions comprising the viral vector of the invention.