Identification of L-dopa immunoreactivity in some neurons in the human mesencephalic region: a novel dopa neuron group?
The presence of L-3,4-dihydroxyphenylalanine (L-DOPA) immunoreactivity is reported for the first time in some neurons in the human mesencephalic region, using an immunohistochemical method with a newly raised, highly specific anti-L-DOPA antiserum. We have found many L-DOPA-positive/dopamine (DA)-positive and a few L-DOPA-positive/DA-negative cell bodies in dopaminergic regions in the midbrain. The present results suggest the existence of more than one neuronal group of L-DOPA in the human mesencephalon. L-DOPA in one group is an intermediate metabolite for decarboxylation to DA and in another group may exist as an end-product. L-DOPA in the latter neurons could be a neuromodulator and/or neurotransmitter. Thus, we suggest that L-DOPA plays an important role besides being an intermediate of DA in the human mesencephalon.
Komori
K
K
Department of Psychiatry, School of Medicine, Fujita Health University, Toyoake, Japan.
Uesaka
S
S
Yamaoka
H
H
Fujita
K
K
Yamaoka
K
K
Naitoh
H
H
Kuroda
M
M
Karasawa
N
N
Ito
T
T
Kasahara
Y
Y
D004298:Dopamine / Q000276:immunology / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007980:Levodopa / Q000276:immunology / Q000378:metabolism*; D008636:Mesencephalon / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D013378:Substantia Nigra / Q000166:cytology / Q000378:metabolism; D017557:Ventral Tegmental Area / Q000166:cytology / Q000378:metabolism
D007980:Levodopa; D004298:Dopamine