Evaluation of inhibitory actions of antidepressants on muscarinic receptors assessed by a binding assay in the mouse cerebral neocortex

We investigated the inhibitory effects of 32 antidepressants on [³H]N-methylscopolamine ([³H]NMS)-specific binding in the mouse cerebral neocortex to determine which antidepressants should be recommended for patients with Alzheimer's disease (AD). Of those tested, nine antidepressants (10⁻⁴ M) exhibited less inhibitory effect on [³H]NMS-specific binding (<35%): tianeptine (a tricyclic); trazodone (a serotonin 5-HT_2A blocker); sulpiride (a dopamine D₂ blocker); fluvoxamine (a selective serotonin reuptake inhibitor (RI)); milnacipran, levomilnacipran, venlafaxine, and desvenlafaxine (serotonin and noradrenaline RIs); and bupropion (a noradrenaline and dopamine RI). Therefore, these antidepressants show little anticholinergic effect in the brain and are recommended for use in patients with AD.