THC affects cells by binding to cannabinoid receptors. This process leads to an increase of synthesis and release of dopamine. Through looking at changes of the cerebral blood flow and glucose metabolism, functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) can indirectly evaluate dopaminergic function. For humans, acute THC administration is associated with increased activity of the frontal and subcortical region . Since the CB1 receptor concentration rate is highest in these areas , rather than dopaminergic-mediation, endocannabinoid might be the effect on the result.