The present invention provides methods and compositions for enhancing the effect of a neurotrophin on a cell expressing a neurotrophin receptor. The effect is preferably neurotrophin-mediated growth and/or survival, such as neurite growth. The invention employees amphipathic compounds having a hydrophobic membrane-associating face and a hydrophilic face opposed thereto, which preferably mimic the amphipathic domain of the common neurotrophin receptor p75 from amino acid residue 367 to residue 379. Such compounds have charged moieties, polar moieties or combinations that mimic the charged and polar group relationships of p75.sup.NTR 367-379, and include but are not limited to peptide analogues thereof. The hydrophobic membrane-associating face can interact with a membrane-bound neurotrophin receptor, such as TrkA, and the opposing hydrophillic face can interact with a DNA binding protein, such as nuclear transcription factor NFkB.