| Popis: |
The signaling molecular mechanisms in zebrafish response to electricity are unknown, so here we asked if changes to dopaminergic signaling pathways can affect their electrically-evoked locomotion. To answer this question, the effects of multiple selective and non-selective dopamine compounds on the electric response of zebrafish larvae is investigated. A microfluidic device with enhanced control of experimentation with multiple larvae is used, which features a novel design to immobilize four zebrafish larvae in parallel and expose them to electric current that induces tail locomotion. In 6 days post-fertilization zebrafish larvae, the electric induced locomotor response is quantified in terms of the tail movement duration and beating frequency to discern the effect of non-lethal concentrations of dopaminergic agonists (apomorphine, SKF-81297, and quinpirole), and antagonists (butaclamol, SCH-23390, and haloperidol). All dopamine antagonists decrease locomotor activity, while dopamine agonists do not induce similar behaviours in larvae. The D2- like selective dopamine agonist quinpirole enhances movement. However, exposure to non-selective and D1-selective dopamine agonists apomorphine and SKF-81297 cause no significant change in the electric response. Exposing larvae that were pre-treated with butaclamol and haloperidol to apomorphine and quinpirole, respectively, restores electric locomotion. The results demonstrate a correlation between electric response and the dopamine signalling pathway. We propose that the electrofluidic assay has profound application potential as a chemical screening method when investigating biological pathways, behaviors, and brain disorders. |
