A method of identifying a modulator Nogo function, the method comprising: (i) providing (a) a BACE polypeptide; (b) a Nogo polypeptide; (c) a test agent under conditions that would permit binding of a BACE polypeptide (a) to a Nogo polypeptide (b) in the absence of the test agent (c) wherein said BACE polypeptide (a) is BACE or a variant thereof or a fragment of either thereof capable of binding Nogo; and polypeptide (b) is Nogo or a variant thereof or a fragment of either thereof capable of binding BACE; (ii) monitoring Nogo mediated activity; and (iii) determining thereby whether the test agent is a modulator of Nogo activity. Modulators identified by a method of the invention and use of such modulators in the manufacture of a medicament for the treatment of disorders responsive to the modulation of Nogo activity such as acute neuronal injury.