WK 6 - Basal ganglia and Cerebellum

5 ganglia

caudate, putamen, globus pallidus, substantia nigra, subthalamic nucleus

corpus striatum

caudate, putamen, and globus pallidus

neostriatum

cuadate and putamen

paleostriatum

globus pallidus

functions

voluntary motor control, procedural learning, eye movements, and cognitive, emotional functions

direct pathway

cortex (stimulates) > striatum (inhibits) > SNr-GPi complex (less inhibition of thalamus) > thalamus (stimulates) > cortex (stimulates) > muscles, etc. > hyperkinetic states

indirect pathway

cortex (stimulates) > striatum (inhibits) > GPe (less inhibition of STN) > STN (stimulates) > SNr-GPi complex (inhibits) > thalamus (stimulating less) > cortex (stimulating less) > muscles, etc. > hypokinetic states

sensory-motor loop

prepare muscles to action, prior to actual muscular activity beginning

association loop

helps with spatial awareness and the cognitive aspects of focused attention on a task

oculomotor loop

coordinate eye movements, particularly saccadic movements and tracking of moving objects

limbic loop

influences emotional responses to event, draws from memories of events, and includes motivation and the emotional aspects of focused attention

feedforward processing

the cerebellum cannot generate self-sustaining patterns of neural actiivty

divergence and convergence

the cerebellar network receives inputs, processes them extensively, and sends out the results through a limited number of output cells

modularity

module consists of small clusters of neurons that appear to function independently

plasticity

cells are susceptible to modification of their strength

cerebellar nuclei

dentate, fastigial, emboliform, globose

superior peduncle

major pathway for output of the cerebellum to other structures; efferent

middle peduncle

compromised of afferent fibers projecting into the cerebellum from the sensory and motor regions of the cerebral cortex

inferior peduncle

carries both afferent and efferent fibers involved with integrating proprioceptive information

vestibulocerebellum

involved with eye movements and balance reactions

spinocerebellum

involved with the control of the trunk and proximal muscles of arms and legs

pontocerebellum

involved with grading of movements and adjusting movements to meet the task demands