MAPT and Alzheimer disease: Importantly, synaptic dysfunction and neurotransmitter imbalances, and primarily acetylcholine, dopamine, noradrenaline, serotonin, glutamate, and gamma-aminobutyric acid (GABA) are critically involved in the pathophysiology of NPS in AD, highlighting their potential role in MBI possibly via the amyloid- and tau-related pathways [99].