Jobs
Careers at NINDS
Why Work at NINDS

Training
Training and Career
   Development
Office of Minority
   Health & Research

Student Programs
Temporary Employment

Summer Program

Contact Us
My Privacy

NINDS is part of the
National Institutes of
Health

Download Adobe Reader

  Print-friendly version

   Email this page

Background: Zebrafish (Danio rerio) have gained acceptance as a valuable model in developmental biology and genetics. The zebrafish genome is extensively known, the animals reproduce abundantly and controllably, and as embryos and larvae they are transparent. Catecholamine-producing cells, identified by expression of tyrosine hydroxylase and dopamine-beta-hydroxylase, are seen as early as 2 days post fertilization; however, the time course of development of catecholamine systems, measured by whole fish or segmental concentrations of catecholamines, has not been studied. We assayed tissue concentrations of the catecholamine precursor, l-3,4-dihydroxyphenylalanine, dopamine (DA), norepinephrine (NE), and epinephrine (EPI) in whole fish and segments, in larvae, juveniles, and adults.

Methods: Tissues were collected at 4, 5, 6, 7, 8, 10, 15, 35, and more than 60 days of age. Whole fish or segments were homogenized and the catechol contents assayed by liquid chromatography with electrochemical detection after batch alumina extraction.

Results: In larvae, DOPA was the main catechol detected, and concentrations of catecholamines were low. Subsequently, DOPA concentrations decreased to a plateau, while catecholamine concentrations increased exponentially in adults. In all tissues of adults, including the brain, heart, and gut, NE was the main catecholamine detected. Gut tissue had higher concentrations of catecholamines than did the brain.

Discussion: In zebrafish, catecholamine systems develop long after larval expression of the genes for the synthetic enzymes. Zebrafish may prove valuable for elucidating mechanisms by which genetic predispositions interact with environmental exposures to produce degeneration of catecholamine systems in adults, as in Parkinson disease.

Last updated September 04, 2008