mRNA expression of nAChR subunits in the zebrafish brain portions that contain reward pathway related structures.

The primers designed (see table 1) were used in a standard RT-PCR to determine if zebrafish brain expressed specific subunits of nAChR. PCR products were separated in a 2% agarose gel. Lanes 1: DNA marker; 2: no RT; 3: β-actin; 4: α6; 5: β2; 6: α4 and 7: α7.

Levels of pCREB protein in the zebrafish brain following nicotine-CPP.

a) Western blot of pCREB in control and nicotine-paired zebrafish (CPP positive) that were euthanized 1.5 or 3 h following CPP test. b) Quantitative densitometry analysis of the positive band obtained in (a) expressed as a ratio relative to control zebrafish euthanized 1.5 h following CPP test. N = 6 per group, **p<0.01 Dunnett’s test after ANOVA.