Evidence for a morphologically distinct subpopulation of striatipetal axons following injections of WGA-HRP into the ventral tegmental area in the rat.
Following injections of small volumes (10-30 nl) of WGA-HRP (1-2%) into the ventral tegmental area, axonal transport of the lectin-peroxidase conjugate to ventral striatum was evaluated by light microscopy after TMB histochemistry and by electron microscopy following stabilization of the TMB reaction product with DAB and H2O2. Label was distributed more or less evenly in ventral striatum, with only slight patchiness observable in the boundary zone between the nucleus accumbens and ventromedial caudate-putamen. The electron microscope revealed that labeled axons contained markedly flattened vesicles and dense axoplasm and contacted perikarya, dendrites and dendritic spines of short (0.2-0.3 microns) symmetric appositions. Boutons with a similar triad of morphological features were observed in preparations processed for conventional electron microscopy and for tyrosine hydroxylase immunocytochemistry, suggesting that the characteristic morphological features observed are not an epiphenomenon related to histochemical processing.
Zahm
D S
DS
Department of Anatomy and Neurobiology, St. Louis University School of Medicine, MO 63104.
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D003342:Corpus Striatum / Q000166:cytology* / Q000648:ultrastructure; D006735:Horseradish Peroxidase; D008854:Microscopy, Electron; D009411:Nerve Endings / Q000648:ultrastructure; D009434:Neural Pathways / Q000033:anatomy & histology; D051381:Rats; D011919:Rats, Inbred Strains; D013681:Tegmentum Mesencephali / Q000166:cytology* / Q000648:ultrastructure; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase