Microfluidic Devices for Investigation of Zebrafish Larvaes Electrotaxis and their Applications to Dopamine System Studies

Zebrafish (Danio rerio) have been used as a model organism for behavioral screening assays due to their high genetic homology with humans. However, research on zebrafish sensory-motor responses to electrical stimuli, called electrotaxis, has been overlooked. We demonstrated the larvae could orient and swim towards the anode and increasing the electrical strength resulted in a stronger electrotaxis. Also, the zebrafish tended to exhibit a lower electrotaxis during the night than the daytime. We showed that electrotaxis is modulated by their D2-like dopamine receptors. Moreover, we examined the tail-beat frequency (TBF) and response duration of zebrafish electrotaxis. We observed that the highest TBF occurs at the lowest current while the response duration was longest at the intermediate currents. We also explored the role of Pannexin1 protein membrane (Panx1) in the zebrafish. It was shown that Panx1 might play an effective role in modulating electrotaxis at lower currents.