Basal Ganglia Flashcards
What structure does the putamen coincide with?
insula
What structure is found on the lateral walls of the lateral ventricle?
caudate nucleus (head)
What does the anterior limb of the internal capsule separate?
caudate and lenticular nucleus (putamen and globus pallidus)
What are the major functions of the basal ganglia?
motor control, mediated by interactions with motor cortex & other structures
involved in most other cortical functions as well
circuit include multiple, parallel loops that modulate cortical output
What does the striatum consist of?
caudate nucleus, nucleus accumbens, putamen
What is the input for the basal ganglia?
cortical afferents to striatum (& subthalamus)
What is the output for the basal ganglia?
globus pallidus interna (GPi), substantia nigra reticular (SNr)
What do the excitatory connections of the basal ganglia use?
glutamate
What do the inhibitory connections of the basal ganglia use?
GABA
T/F: Basal Ganglia influence motor cortex directly.
False. BG influences descending motor pathway by affecting activity in cortical motor areas
What is the striatum divided into?
striosomes
What is the net result of the direct pathway?
more cortical ouput
How does the direct pathway work?
- excitatory input from cerebral cortex goes to striatum
- striatum sends inhibitory input to GPi
- GPi fails to inhibit thalamus, which sends excitatory input to the cortex
What structure degenerates in Huntington’s Disease?
degeneration of striatum (caduate > putamen)
What is the net results of the indirect pathway?
decreased cortical output
