Flashcards in Basal Ganglia Deck (14):
What are the 4 nuclei of the basal ganglia?
1- striatum (caudate nucleus + putamen).
2- globus pallidus.
3- subthalamic nucleus.
4- substantia nigra.
Form the motor loop.
Basal ganglia, cortex, and thalamus
There are two pathways from the striatum to the thalamus.
Striatum ==> internal pallidum ==> thalamus.
Striatum ==> external pallidum ==> subthalamus ==> internal pallidum ==> thalamus.
Has a net facilitatory effect on cortex (positive feedback loop).
Has a net inhibitory effect on the cortex (negative feedback loop).
Dopamine inhibit the .............. pathway and facilitate the ...............
- Inhibit the indirect (through D2).
- facilitate the direct (through D1)
Reduce inhibition of thalamocortical neurons and facilitate the cortically initiated movements.
The dopaminergic projection from the SN to the striatum
What are the motor functions of the basal ganglia?
- motor planning.
- facilitate automatic performance of learned motor acts.
- prevent unwanted involuntary movements.
- tone and posture.
What are the cognitive/limbic functions of the basal ganglia?
Motivation - emotion - memory
Underactivity of the indirect pathway (dyskinesia + hypotonia)
Overactivity of the indirect pathway (akinesia + bradykinesia)
What are the four primary motor symptoms of Parkinson’s disease?
1- tremor (resting).
4- postural instability.
Non-motor symptoms of Parkinson’s disease.
- autonomic dysfunction.
- cognitive and neurobehavioral problems.
- sensory and sleep difficulties.