Neurotoxicity assessment using zebrafish.
BACKGROUND
Transparency is a unique attribute of zebrafish that permits direct assessment of drug effects on the nervous system using whole mount antibody immunostaining and histochemistry.


METHODS
To assess pharmacological effects of drugs on the optic nerves, motor neurons, and dopaminergic neurons, we performed whole mount immunostaining and visualized different neuronal cell types in vivo. In addition, we assessed neuronal apoptosis, proliferation, oxidation and the integrity of the myelin sheath using TUNEL staining, immunostaining and in situ hybridization. The number of dopaminergic neurons was examined and morphometric analysis was performed to quantify the staining signals for myelin basic protein and apoptosis.


RESULTS
We showed that compounds that induce neurotoxicity in humans caused similar neurotoxicity in zebrafish. For example, ethanol induced defects in optic nerves and motor neurons and affected neuronal proliferation; 6-hydroxydopamine caused neuronal oxidation and dopaminergic neuron loss; acrylamide induced demyelination; taxol, neomycin, TCDD and retinoic acid induced neuronal apoptosis.


CONCLUSIONS
Effects of drug treatment on different neurons can easily be visually assessed and quantified in intact animals. These results support the use of zebrafish as a predictive model for assessing neurotoxicity.
Parng
Chuenlei
C
Phylonix Pharmaceuticals, Inc., 100 Inman St., Cambridge, MA 02139, USA. Chuenlei@phylonix.com
Roy
Nicole Marie
NM
Ton
Christopher
C
Lin
Yingxin
Y
McGrath
Patricia
P
D020106:Acrylamide / Q000633:toxicity; D000818:Animals; D000873:Anthracenes / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000187:drug effects; D000431:Ethanol / Q000633:toxicity; D005977:Glutarates / Q000633:toxicity; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D009046:Motor Neurons / Q000187:drug effects; D009186:Myelin Sheath / Q000187:drug effects; D009355:Neomycin / Q000633:toxicity; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D009498:Neurotoxins / Q000633:toxicity*; D009900:Optic Nerve / Q000187:drug effects; D016627:Oxidopamine / Q000633:toxicity; D017239:Paclitaxel / Q000633:toxicity; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D018675:Toxicity Tests / Q000379:methods*; D014212:Tretinoin / Q000633:toxicity; D015027:Zebrafish
D000873:Anthracenes; D005977:Glutarates; D009498:Neurotoxins; D000072317:Polychlorinated Dibenzodioxins; C432165:pyrazolanthrone; D020106:Acrylamide; C019417:alpha-hydroxyglutarate; D000431:Ethanol; D014212:Tretinoin; D016627:Oxidopamine; D009355:Neomycin; D017239:Paclitaxel