In vivo electrochemical measurements of exogenously applied dopamine in Drosophila melanogaster.
Anal Chem
; 81(5): 1848-54, 2009 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-19192966
ABSTRACT
Carbon-fiber microelectrodes coupled with electrochemical detection have been used extensively for the analysis of biogenic amines. In order to determine the functional role of these amines, in vivo studies have primarily used rats and mice as model organisms. Here, we report on the development of these microanalytical techniques for in vivo electrochemical detection of dopamine in the adult Drosophila melanogaster central nervous system (CNS). A triple-barrel micropipet injector was used to exogenously apply three different concentrations of dopamine, and a cylindrical carbon-fiber microelectrode was placed in the protocerebral anterior medial brain area where dopamine neurons are densely populated. Background-subtracted fast-scan cyclic voltammetry was used to measure dopamine concentration in the fly CNS. Distinct differences are shown for the clearance of exogenously applied dopamine in the brains of wild type flies versus fumin (fmn) mutants lacking a functional dopamine transporter. The current response due to oxidation of dopamine increased significantly from baseline for wild type flies following cocaine incubation. Interestingly, the current remained unchanged for mutant flies under the same conditions. These data confirm the accepted theory that cocaine blocks dopamine transporter function and validates the use of in vivo electrochemical methods to monitor dopamine uptake in Drosophila. Furthermore, after incubation with tetrodotoxin (TTX), a sodium channel blocker, there was a significant increase in peak oxidation current in the wild type flies; however, the current did not significantly change in the fmn mutant. These data suggest that factors that affect neuronal activity via ion channels such as TTX also influence the function of the dopamine transporter in Drosophila.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Dopamina
/
Sistema Nervoso Central
/
Drosophila melanogaster
/
Técnicas Eletroquímicas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Anal Chem
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos