Fig. 4.

Determining the need to quench NicA2 activity in brain tissue. Brains from the Repeated Nicotine Dose experiment (see Fig. 7 for main result) were split so that one hemisphere was homogenized in MeOH prior to extraction and processing while the other half was not. In animals pretreated with BSA, homogenization in MeOH did not affect the measured nicotine concentrations. In rats pretreated with NicA2, the hemispheres that were not homogenized in MeOH had significantly lower nicotine concentrations, confirming the need to include this step when processing brain tissue. Percentages above bars are the difference between unquenched and quenched groups. * p < 0.05, two-tailed paired t tests. Mean ± SD, n = 5/group