Fingerprinting of psychoactive drugs in zebrafish anxiety-like behaviors.

A major hindrance for the development of psychiatric drugs is the prediction of how treatments can alter complex behaviors in assays which have good throughput and physiological complexity. Here we report the development of a medium-throughput screen for drugs which alter anxiety-like behavior in adult zebrafish. The observed phenotypes were clustered according to shared behavioral effects. This barcoding procedure revealed conserved functions of anxiolytic, anxiogenic and psychomotor stimulating drugs and predicted effects of poorly characterized compounds on anxiety. Moreover, anxiolytic drugs all decreased, while anxiogenic drugs increased, serotonin turnover. These results underscore the power of behavioral profiling in adult zebrafish as an approach which combines throughput and physiological complexity in the pharmacological dissection of complex behaviors

A3 adenosine receptors modulate behavior and serotonergic system in zebrafish: Mediation by the nitric oxide pathway

<p>Extracellular serotonin (5-HT) levels in the brain are thought to mediate many different behavioral functions, including anxiety and stress; the main mechanism to regulate extracellular 5-HT levels is through reuptake, which are regulated by a plethora of mechanisms. Here, we demonstrate that activation of A3 adenosine receptors by IB-MECA decreases scototaxis, geotaxis, neophobia and arousal in zebrafish in vivo, increases extracellular brain 5-HT levels ex vivo, and increases 5-HT uptake in vitro. The effects of IB-MECA on 5-HT uptake, on extracellular 5-HT concentrations and on scototaxis are dependent on L-type calcium channels, nitric oxide synthase, and serotonin transporters; the effects of IB-MECA on geotaxis, on the other hand, are dependent on nitric oxide synthase, but not on serotonin transporters or calcium channels. These results underline a potential target to control 5-HT uptake and its behavioral consequences.</p

Effects of (A) buspirone, (B) diazepam and (C) caffeine on time on white (upper left), risk assessment (upper right), thigmotaxis (lower left), and freezing (lower right).

<p>Bars represent standard error of the mean, and whiskers represent the 2.5 and 97.5 percentile. *, p<0.05; **, p<0.01; ***, p<0.001.</p

Effects of (A) caffeine, (B) ethanol, (C) bupropion and (D) verapamil on time on white (top) and entries on white (bottom).

<p>Bars represent standard error of the mean, and whiskers represent the 2.5 and 97.5 percentile. *, p<0.05; **, p<0.01; ***, p<0.001.</p

Behavioral fingerprint of selected drugs on the scototaxis test.

<p>Pharmacological manipulations were hierarchically clustered to link compounds to behaviors. In the clustergram, each cell represents the Maximum Predictive Value (red – higher than controls; green – lower than controls).</p

Drugs which cluster on the 'anxiolytic' group decrease 5-HT turnover in the brain.

<p>(A) Turnover rates, as measured by 5-HIAA:5-HT ratios, normalized to the values of vehicle-treated animals, for the following drugs: fluoxetine (FLX; chronic treatment with 10 mg/kg); chlordiazepoxide (CDZ; 0.02 mg/kg); clonazepam (CLZ; 0.05 mg/kg); diazepam (DZP; 1.25 mg/kg); buspirone (BUS; 50 mg/kg); ethanol (EtOH, 2.5%); dizocilpine (MK; 0.005 mg/kg); verapamil (VER; 5 mg/kg); WAY 100,635 (WAY; 0.03 mg/kg); and SB 224,289 (SB; 2.5 mg/kg). Asterisks mark statistically significant differences in relation to vehicle-treated animals (F_{10, 43} = 45.99, p<0.0001, one-way ANOVA followed by Dunnett's Multiple Comparison test). Bars represent mean (B) Correlation between turnover rates (<i>Y</i>-axis) and time spent in the white compartment (<i>X</i>-axis) for vehicle- and drug-treated animals (<i>n</i> = 4 for each point). Points represent means and error bars represent standard errors. A negative correlation is found between the decrease in serotonin turnover and the increase in time on white produced by a drug (r² = 0.5688, p = 0.0073).</p