5,7-Dihydroxytryptamine--a selective marker of dopaminergic or serotonergic neurons?
The aim of the present study was to investigate whether 5,7-dihydroxytryptamine (5,7-DHT), an autofluorescent serotonin derivative, can be used as a specific marker for serotonergic or dopaminergic neurons in rat mesencephalic cultures. To this end, primary cultures were prepared from the ventral brain stem of 14-day-old Wistar rat foetuses and kept in culture for 10 days (DIV10). At DIV10, the cultures were characterized immunocytochemically with antibodies raised against tyrosine hydroxylase (TH; a marker for catecholaminergic/ dopaminergic neurons) and serotonin (5-HT). 5,7-DHT labelling of the neurons was investigated after incubation with 25 microM of the serotonin derivative (plus 0.005% ascorbic acid) for 60 min at 37 degrees C, followed by incubation with primary antibodies against TH or serotonin and a fluorescence (Cy3)-labelled secondary antibody. Using confocal laser scanning microscopy, this double immunofluorescence approach demonstrated that all cells which had accumulated 5,7-DHT additionally displayed anti-5-HT immunoreactivity, whereas no evidence was found for 5,7-DHT labelling of TH immunoreactive cells. Preincubation with the selective serotonin reuptake inhibitor fluvoxamine maleate (10 microM) prevented the loading of the 5-HT-positive cells with 5,7-DHT. In conclusion, the present data indicate that 5,7-DHT specifically labels serotonergic cells in rat midbrain cultures. Thus, 5,7-DHT can be used for the identification of living serotonergic neurons even in the presence of dopaminergic neurons.
Franke
Heike
H
Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Härtelstrasse 16-18, 04107 Leipzig, Germany. frah@medizin.uni-leipzig.de
Grosche
Jens
J
Illes
Peter
P
Allgaier
Clemens
C
D015116:5,7-Dihydroxytryptamine / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D001933:Brain Stem / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D002478:Cells, Cultured; D004298:Dopamine / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D005333:Fetus; D009474:Neurons / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000032:analysis / Q000378:metabolism / Q000502:physiology*
D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D004298:Dopamine