title: Immunohistochemical distribution of pro-somatostatin-related peptides in cerebral cortex.
abstract: Mammalian brain contains 3 peptides related to the pro-somatostatin molecule: somatostatin-14 (SS14), the form originally identified from hypothalamic extracts, somatostatin-28 (SS28) and somatostatin 28 (1-12) (SS28 (1-12)). By using antibodies which selectively recognize one or more of these 3 somatostatin-related peptides, we have characterized their immunohistochemical distribution in neocortex. These somatostatin-related peptides have a specific laminar distribution in cortex and are differentially distributed such that SS28 is largely restricted to cell bodies, whereas SS28 (1-12) is preferentially localized in neuronal processes and terminals in a density which far exceeds that revealed by SS-14 immunoreactivity. These data suggest that there may be an intraneuronal transformation from a SS28-like peptide to a SS28 (1-12)-like peptide. In addition, the enriched distribution of nerve fibers containing the antigenic determinant, SS28 (1-12), strongly implies that somatostatin-related peptides constitute a major neurotransmitter system in neocortex. The morphological characteristics of this system are homologous with long projection pathways such as the cortico-cortical specific intrinsic systems as well as projections.
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007395:Interneurons / Q000378:metabolism; D009434:Neural Pathways / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D013003:Somatosensory Cortex / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism*; D053561:Somatostatin-28; D009435:Synaptic Transmission
chemical_list: D010455:Peptides; C029993:somatostatin-like peptides; D013004:Somatostatin; D053561:Somatostatin-28