title: On the origin of dynorphin A and alpha-neo-endorphin in the substantia nigra.
abstract: The substantia nigra contains among the highest dynorphin A (Dyn A) and alpha-neo-endorphin (alpha-Neo) concentrations in the central nervous system. No dynorphin positive cell bodies are found there, only a dense network of nerve fibers and terminals. The present study provides evidence that the Dyn A and alpha-Neo in the substantia nigra are in neural processes arising from cells located in the head of the caudate nucleus. This neuronal system has been characterized by assaying Dyn A and alpha-Neo in the substantia nigra after a number of surgical transections of neuronal pathways in the rat forebrain and midbrain. Fibers containing dynorphins and neo-endorphins seem to pass through the internal capsule, ansa lenticularis, and medial forebrain bundle on their way from the striatum to the substantia nigra.
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D004399:Dynorphins; D004723:Endorphins / Q000096:biosynthesis*; D008297:Male; D009928:Organ Specificity; D010446:Peptide Fragments / Q000096:biosynthesis*; D011498:Protein Precursors / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013238:Stereotaxic Techniques; D013378:Substantia Nigra / Q000166:cytology / Q000378:metabolism*
chemical_list: D004723:Endorphins; D010446:Peptide Fragments; D011498:Protein Precursors; C025681:alpha-neoendorphin; D004399:Dynorphins