Browsing by Author "Enckell, Louise"

VMAT2 is an integral membrane protein with a crucial role in the monoaminergic system. It transports cytosolic dopamine and other neurotransmitters into synaptic vesicles for storage and later exocytotic release. VMAT2 has been found to have a neuroprotective effect, for instance by preventing oxidation of free cytosolic dopamine. Research has suggested that increased VMAT2 expression or function could have a protective effect against Parkinson’s disease. Rapid embryonic development, transparency during larval stage, and high homology with the human genome are some of the factors that makes the zebrafish a popular model organism. The aim of this research was to optimize the protocol for immunohistochemistry with an anti-dopamine antibody, and to find out how the absence of a functioning vmat2 gene in zebrafish mutants (vmat2-/-) affects dopamine immunostaining, compared to embryos with normal vmat2 function (vmat2+/+). Zebrafish larvae were fixed in a fixation agent, whereafter brains were dissected and immunostaining was performed. Individual methods in the protocol were adjusted for each experiment until the result of the dopamine staining was considered optimal. We found that the choice of fixative affected dopamine staining strongly. A clear reduction in dopamine immunoreactive cells was observed in zebrafish larvae lacking a functioning vmat2 gene compared to zebrafish with normal vmat2 function. The results also suggested that the localization of dopamine-storing cells in zebrafish larvae resembles more tyrosine hydroxylase 2 than tyrosine hydroxylase 1 expression pattern, especially in the hypothalamus. Vmat2-/- zebrafish could be useful when investigating how monoamine transport affects different diseases and their pharmacological treatment.