The brain cells function by electrically encoding, processing and transmitting information. Deep brain stimulation affects the electrical functions of neurons, but the mechanism by which it alters those functions, are unknown. According to some hypothesis, the reduction of the effects of an abnormal neuronal activity occurs because of inhibition, depolarization blockade or the adjustment of neuronal activity to a constant rate.
The depolarization of axons terminating in target structure by deep brain stimulation causes these terminals to discharge and release neurotransmitters. DBS may cause a flood of inhibitory neurotransmitters that effectively shuts down neurons in the target structures.
If a neuron is constantly depolarized but below the threshold need to produce an action potential, the threshold for producing an action potential increases. Consequently, neurons find it more difficult to fire because the threshold increases.
Altering erratic neuronal activity:
DBS alters the abnormal discharge activity that results from the disease. It has been suggested that irregular or chaotic firing of neurons may be more disruptive of normal function than a constant and regular pattern of activity. It is possible that DBS drives the abnormally discharging neurons into a pattern of more regular firing that is less deleterious.