Enhancing Neuroplasticity and Frontal Lobe Function in Patients With Mild Alzheimer's Disease

PAS simulates in humans the induction of long-term potentiation (LTP), a prototype of synaptic neuroplasticity. PAS involves the repetitive pairing of electrical stimulation of the median nerve with - 25 ms later - transcranial magnetic stimulation (TMS) of the contralateral DLPFC. As such, these two stimulations arrive simultaneously in the DLPFC and result in potentiation of TMS induced cortical evoked potential, analogous to in vitro LTP.

PAS-C is a control PAS paradigm in which TMS to the left DLPFC follows the electrical stimulation of the right median nerve by 100 ms, and, thus, does not result in contemporaneous occurrence of the two stimulations in the cortex and consequently no LTP.