Dynamically Coupled, High-Frequency Reentrant, Non-linear Oscillators Embedded in Scale-Free Basal Ganglia-Thalamic-Cortical Networks Mediating Function and Deep Brain Stimulation Effects

  • Erwin B. Montgomery Jr.


The remarkable success of deep brain stimulation (DBS) for treating neurological disorders has increased interest in the physiology and pathophysiology of the basal ganglia (BG) and has forced re-evaluation of present theories of brain function. Recent studies of BG neuronal physiology suggest that the BG form reentrant closed-loop networks with the cortex (Ctx) and thalamus (Th), generating non-linear oscillators. Further, these oscillators are dynamically coupled to form networks with unique local properties that have been described for coupled oscillators and larger-scale properties that have been described for scalefree networks. Here, I integrate results of neurophysiological studies with those of mathematical and computational studies of non-linear oscillators and scale-free networks and propose a new theory of BG-Th-Ctx function. I contrast the new theory with present theories, not only regarding BG-Th-Ctx function but also how function or behavior is represented in brain activity in general. A corollary to the new theory is that function is determined by the network and not by distinct anatomical structures. This notion contrasts with the current modulist explanation of normal function and disease pathophysiology.