Immunolocalization of catecholamine enzymes, serotonin, dopamine and L-dopa in the brain of Dicentrarchus labrax (Teleostei).
Antisera to serotonin (5-HT), dopamine, and L-dopa, and to the catecholamine synthesizing enzymes, tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyl transferase (PNMT), were used to localize monoamine containing neurones in the brain of Dicentrarchus labrax (sea bass). In the brain stem, 5-HT-immunoreactive (ir) neurones were recognized in the ventrolateral medulla, vagal motor area, medullary, and mesencephalic raphe nuclei and in the dorsolateral isthmal tegmentum. In the hypothalamus, liquor-contacting 5-HT neurones were seen in various regions of the paraventricular organ. Virtually all regions of the brain contained a dense innervation by 5-HT fibres and terminals. DBH-ir neurones were restricted to three brain stem areas: the locus coeruleus, the area postrema, and the reticular formation of the lower medulla. Neurones in these three groups also displayed TH-ir, and in the latter area, PNMT-ir in addition. In the locus coeruleus and area postrema, TH-ir neurones outnumbered DBH-ir neurones, an observation substantiated by the presence of dopamine-ir neurones. In the forebrain, dopamine- and TH-ir neurones were found in the olfactory bulb, ventral/central telencephalon, periventricular preoptic, and suprachiasmatic areas, dorsolateral and ventromedial thalamus, and posterior tuberal nucleus. In the paraventricular organ, the distribution and morphology of dopamine-ir neurones was similar to that observed with anti-5-HT, but the vast majority of cells were not TH-ir, suggesting accumulation of dopamine by uptake from the ventricle, rather than by synthesis. L-dopa-ir neurones were found only in the central telencephalon, preoptic recess, and dorsolateral thalamus. Fibres and terminals immunoreactive for dopamine, TH, and DBH showed a broadly similar distribution. The results are discussed in relation to the monoaminergic systems previously reported in other teleostean species and the mammalian brain.
Batten
T F
TF
Department of Clinical Medicine, University of Leeds, UK.
Berry
P A
PA
Maqbool
A
A
Moons
L
L
Vandesande
F
F
D000818:Animals; D000918:Antibody Specificity; D001492:Bass / Q000378:metabolism*; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology* / Q000276:immunology; D002395:Catecholamines / Q000378:metabolism*; D003429:Cross Reactions; D004298:Dopamine / Q000276:immunology / Q000378:metabolism*; D004299:Dopamine beta-Hydroxylase / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D007980:Levodopa / Q000276:immunology / Q000378:metabolism*; D010625:Phenylethanolamine N-Methyltransferase / Q000276:immunology / Q000378:metabolism; D012701:Serotonin / Q000276:immunology / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000276:immunology / Q000378:metabolism
D002395:Catecholamines; D012701:Serotonin; D007980:Levodopa; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D010625:Phenylethanolamine N-Methyltransferase; D004298:Dopamine