Abstract: A method is disclosed for delivering biologically active agents to a mammalian brain by administering a complex of the biologically active agent with a polycationic carrier coupled to 2-20 eicosapentaenoic acid or docosahexaenoic acid moieties and additional eicosapentaenoic acid or docosahexaenoic acid moieties. The polycationic carrier is poly-lysine, poly-arginine or poly-ornithine of 5-50 amino acid residues. The addition of a targeting moiety selected from tetanus toxin C fragrant, .alpha.-bungarotoxin and nerve growth factor to the complex facilitates delivery of the biologically active agent to glial tissue, or to cortical, cholinergic and adrenergic neurons.