A compound is provided that has the formula
NH.sub.2CH.sub.2CH.sub.2CH.sub.2C(O)N--R (I) where R is a moiety capable
of crossing the blood brain barrier and is as a free compound serotonin,
dopamine blood brain barrier (BBB) peptide, membrane translocating
protein, TAT peptides, bradykinin, beta-endorphin, bombesin, calcitonin,
cholecystokinin, an enkephalin, dynorphin, insulin, gastrin, substance P,
neurotensin, glucagon, secretin, somatostatin, motilin, vasopressin,
oxytocin, prolactin, thyrotropin, an angiotensin, galanin, neuropeptide
Y, thyrotropin-releasing hormone, gonadotropnin-releasing hormone, growth
hormone-releasing hormone, luteinizing hormone, vasoactive intestinal
peptidetransferrin, glucosylamnine, amino saccharin, lactylamine,
leucine, tryptophan, glutamate and amino cholines.