A neuropeptide; structurally similar to somatostatin-28; expressed in the human brain and in interneurons of the rat hippocampus and cerebral cortex; binds to SST receptors (IC50s = 2.8, 7.1, 0.2, 3, and 13.7 nm for SST1-5, respectively); found at similar levels as cortistatin-14 in mouse AtT20 cells but secreted at a lower level