Basal Ganglia Flashcards
Basal Ganglia
Four interconnected subcortical nuclei, involved in voluntary movement, cognition and emotion
Curvy thing
Caudate nucleus
Go memorize the different images of coronal brain cuts
Internal capsule separates…
Caudate from Putamen, globus pallidus
Loop
Basal Ganglia-> Thalamus -> Cortex -> Basal ganglia - > thalamus -> cortex
Caudal nucleus is…
very big in rostral section
Whats right under/side of the internal capsule?
Putamen and globus pallidus
Lateral walls of lateral ventricles…
Caudate nucleus
Ventral anterior and ventral lateral nuclei
Specific relay nuclei that connect the cerebellum and basal ganglia w motor cortex
Direct pathway of basal ganglia’s modulation of activity of thalamic neurons
Facilitates movement
Indirect pathway of basal ganglia’s modulation of activity of thalamic neurons
Inhibits movement
Putamen and Caudate nucleus
Inputs for Basal ganglia
Caudate nucleus
Mostly involved in cognition
Putamen
Mostly movement
Thalamus to cortex? Inhibitory or excitatory?
Excitatory
Cortex to putamen
Excitatory
Almost all connections of basal ganglia are..
inhibitory
Globus pallidus is…
Output structure of Basal Ganglia
There is internal and external segment
Internal segment is output back to the thalamus
If you are not moving then the inhibitory neurons in the globus palidus internal segment…
Are firing like crazy
therefore less excitation of cortex
Cortex excites neurons in putamen
Putamens inhibitory neurons inhibit the GP so now thalamus is not inhibited and can excited the cortex
Indirect pathway
STN subthalamic nucleus neurons are excitatory and activate GP inhibitory firing which inhibits thalamus
Substantia niagra
Dopamine neurons
Project to caudate nucleus and Putamen
Dopamine effect on pathways
Excites direct pathway
Inhibits indirect pathway
Action selection
Selecting appropriate movements
Inhibits incorrect movements