Autoradiography with [3H]-imipramine, a selective serotonin transporter (SERT) inhibitor, revealed reduced binding in the putamen and frontal, temporal, and cingulate cortex, indicating the loss of presynaptic 5-HT terminals.191, 192, 193 Decreased SERT binding was also observed in different brain areas, including the cortical, limbic, sensory, and motor regions in patients with mild cognitive impairment using magnetic resonance (MR) imaging and PET, which correlated with impaired auditory-verbal and visual-spatial memory in these patients.194. Here, SLC6A4 is linked to Cognitive impairment.