Co-localization of tyrosine hydroxylase and glutamate decarboxylase in a subpopulation of single nigrotectal projection neurons.
The neurotransmitter phenotype(s) of nigral neurons innervating the superior colliculus (SC) in the rat was examined using a combination of immunohistochemical techniques and fluorescent retrograde tracing. After double-immunofluorescent histochemistry for tyrosine hydroxylase (TH) and glutamate decarboxylase (GAD), single cells in the rostral ventrolateral portion of the substantia nigra pars reticulata (SNr) and to a lesser extent the substantia nigra pars lateralis (SN1) displayed immunoreactivity to both antigens. Furthermore, following True blue (TB) injections into the SC and incubation for both TH and GAD immunoreactivity, a considerable number of cells in the SNr retrogradely labeled with TB (approximately 10%) were also immunopositive for both synthetic enzymes. The present study provides evidence for the coexistence of TH and GAD and thus, the coexistence of dopamine and GABA in a subpopulation of single nigrotectal projection cells.
Department of Anatomy, University of Toronto, Ont., Canada.
K J
KJ
Campbell
M
M
Takada
T
T
Hattori
D000818:Animals; D004298:Dopamine / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D007150:Immunohistochemistry; D009434:Neural Pathways / Q000166:cytology; D009474:Neurons / Q000201:enzymology*; D010641:Phenotype; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000033:anatomy & histology / Q000166:cytology / Q000201:enzymology*; D013477:Superior Colliculi / Q000166:cytology / Q000201:enzymology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005456:Fluorescent Dyes; D005680:gamma-Aminobutyric Acid; D014446:Tyrosine 3-Monooxygenase; D005968:Glutamate Decarboxylase; D004298:Dopamine