Fig. 6

Effects of dopamine receptor antagonists on nicotine-induced behavioral responses in wild-type and neu1-knockout zebrafish. WT and neu1-KO zebrafish were pretreated with risperidone (300 µg/L) or haloperidol (2.5 µM) by waterborne exposure for 30 min prior to behavioral testing, followed by transfer to the experimental tank containing Nco (2.5 mg/L). Swimming behavior was recorded for 10 min. A Representative swimming trajectories in WT and neu1-KO zebrafish exposed to Nco alone or Nco plus haloperidol. B–E Quantitative analysis of swimming behavior in WT zebrafish treated with Nco alone or Nco plus haloperidol. B Total swimming distance. C Swimming distance in the upper layer. D Time spent swimming in the upper layer. E Duration of excited swimming behavior. F Representative swimming trajectories in WT and neu1-KO zebrafish exposed to Nco alone or Nco plus risperidone. G–J Quantitative analysis of swimming behavior in WT and neu1-KO zebrafish treated with Nco alone or Nco plus risperidone. G Total swimming distance. H Swimming distance in the upper layer. I Time spent swimming in the upper layer. J Duration of excited swimming behavior. Different letters indicate statistically significant differences between the groups. n.s., not significant. n = 6