Transcript Slide ()

Scheme of the main cortico-BG projections and intra BG nuclei circuitry. The principal network is based on a series of disynaptic and trisynaptic
bidirectional connections. The striatum and STN are excited by the cortical projections and they project to the GPe and GPi in both inhibitory and excitatory
manner, respectively. The central location of the GPe plays a key role in the modulation of BG output projections, either directly via the GPi or indirectly via
the STN and eventually the striatum. Neuronal firing activity related to a simple movement is schematically depicted. Following a “go” signal, the motor
areas become phasically activated and dispatch a simultaneous volley to the motor striatum and STN. Note that GPe receives activity of opposite
functional (excitatory or inhibitory) sign by disynaptic connections and it is in a central position to modulate GPi output activity. BG, basal ganglia; SNc,
Source: Chapter 5. Pathophysiology of the Basal Ganglia and Movement Disorders, Movement Disorders, 3e
substantia nigra pars compacta; GPe, globus pallidus pars externa; Gpi, globus pallidus pars interna; STN, subthalamic nucleus; STR, striatum.
Citation: Watts RL, Standaert DG, Obeso JA. Movement Disorders, 3e; 2012 Available at: http://mhmedical.com/ Accessed: April 04, 2017
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