Ultrastructural organization of GABA-like immunoreactive profiles in the weaver substantia nigra.
GABA-like immunoreactivity (GABA-LI) in the substantia nigra pars compacta (SNc) of mutant weaver mice was investigated at the electron microscope level. Eight-week-old homozygous mutant weaver mice, paired with wildtype littermates as controls, were perfused with a buffered paraformadehyde/acrolein solution. Sections containing the SN were immunocytochemically reacted with an antiserum to GABA using the peroxidase-antiperoxidase (PAP) procedure. Ultrastructural examination revealed that profiles of GABA-LI dendrites were decreased in number while profiles of labeled axonal processes were increased. In addition, there were an increased number of GABA-LI terminals in contact with similarly labeled GABA-LI dendrites. Double-labeling experiments using the antibodies to GABA and dopamine D(2) receptors showed that a small number of GABA-LI profiles exhibited D(2)-like immunoreactivity in both controls and weavers. These results suggest that the GABA-LI synaptic connections are altered as a result of the loss of DA neurons in the SNc of the weaver mice.
Smith
Diane E
DE
Department of Cell Biology & Anatomy, LSU Medical School-New Orleans, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA. desmi@lsuhsc.edu
Xu
Shu-Guang
SG
D000818:Animals; D003712:Dendrites / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D004195:Disease Models, Animal; D004298:Dopamine / Q000172:deficiency; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008818:Mice, Neurologic Mutants; D008854:Microscopy, Electron; D009410:Nerve Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009422:Nervous System Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009434:Neural Pathways / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000235:genetics; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D017448:Receptors, Dopamine D2; D005680:gamma-Aminobutyric Acid; D004298:Dopamine