FIGURE 4.

Possible therapeutic mechanisms of action of deep brain stimulation. High-frequency stimulation is thought to inhibit local cell body activity and possibly stimulate orthodromic action potentials, antidromically activate afferent neuronal inputs, and stimulate neurons passing near the electrode. Local glial cell activity may also be modulated. Modulation of neurochemical efflux, including neurotransmitters, neuropeptides, and retrograde messengers, may occur both locally and distally. In addition to these short-term changes, long-term adaptations likely occur, including the formation of new synapses and/or regulation of receptor expression.