TABLE 5 Effect of cocaine on [3H]DA accumulation
[3H]DA uptake was assessed at various time points in the absence and presence of the indicated concentrations of cocaine. The combined data from all three experiments (Fig. 7A) (180 data points) were fit to the equation described in Table 4. The time course data for each drug condition were separately applied to the above equation, each of which differed only in the names of the corresponding parameters: Emax1, Emax2, Emax3, Emax4, and Emax5 and t1/2-1, t1/2-2, t1/2-3, t1/2-4, and t1/2-5. Thus, the unconstrained fit led to the reported parameter values. The data were then fit with the constraint that the Emax values were all equal. This resulted in a significant increase in the sum-of-squares (F = 6.34, P < 0.001). Fitting the data with the constraint that the t1/2 values were equal led to a highly significantly increased sum-of-squares (F = 89, P = 0). Constraining the Emax values to equal 100% also led to a modestly significant increase in sum-of-squares (F = 4.19, P = 0.003).