Abstract
CNS effects have been demonstrated for many peptides initially isolated for other purposes from hypothalamic tissue. These effects do not require the mediation of the pituitary or other endocrine organs and, therefore, can be loosely considered as “extra-endocrine”. Although found in locations of the brain inside the blood-brain barrier, peptides can exert significant alterations in the CNS after peripheral injections. The CNS changes persist long after most of the peptide has left the blood stream. In many cases results of studies performed with these peptides in laboratory animals have been extended to clinical investigations. Already there are indications of beneficial effects of peptides found in the hypothalamus in such disorders as parkinsonism, mental depression, and mental retardation. It is reasonable to anticipate that other neurological and mental disorders may be alleviated and performance optimized by brain peptides.