Figure 5. The data indicate no evidence of caffeine dependence. Animals received increasing acute intravenous injections of 1-10 mg caffeine/kg body wt 15 min before the onset of the [¹⁴C] 2-deoxyglucose procedure. LCMR_glc was measured in selected regions of the mesolimbic dopaminergic system that are involved in addiction and reward: ventral tegmental area (VTA); nucleus accumbens, shell (ACCSH); nucleus accumbens, core (ACCCO); and medial prefrontal cortex (MPFCX). *p < 0.05 and **p < 0.01, significantly different from controls, as determined by Dunnett's t-test for multiple comparisons.