Basal Ganglia Flashcards
What are the components that make up the cerebellum?
- Caudate
- Putamen
- Globus Pallidus
- Internus (GPi)
- Externus (GPe) - Substantia nigra
- Pars compacta (SNpc)
- Pars reticularis (SNpr) - Subthalamic Nuclei
What 2 components make up the striatum?
Caudate and putamen
What makes up the lenticulate nucleus?
Putamen and Globus Pallidus internus and externus
What are the 2 brainstem components of the basal ganglia?
Substantia nigra and subthalamic nuclei
Where is the subthalamic nuclei located?
In the midbrain-diencephalic junction
What is the function of the basal ganglia?
Motor control!
What are the 3 ways the basal ganglia helps with motor contol?
- Initiation and execution of movement.
- Helps with regulation of muscle contraction, muscle force, multi-joint movement, and sequencing of movement. - Prevention of unwanted movements through inhibitory control.
- Direct and indirect pathways that work together to help create desired movement.
What structure receives all input for the basal ganglia?
The striatum
Where does the caudate receive input from?
- Heteromodal association cortices
2. Motor areas of frontal lobe involved in eye movements.
Where does the putamen receive input from?
- 1 and 2 order sensory cortices in prietal lobe
- Higher order visual cortices in occipital and temporal lobes
- Premotor cortex and PriMC
- Auditory association cortices temporal lobe.
What are 3 other structures that send input to the striatum?
- SNpc
- Intralaminar nuclei of thalamus
- Subcortical structures about modulatory input from NT systems.
What are the 2 cortices that DO NOT send input to the basal ganglia?
The primary visual and primary auditory cortices.
What are the two structures in charge on basal ganglia output?
The globus pallidus internus and the stubstantia nigra pars reticularis.
What locations do the ventral lateral and ventral anterior nuclei project output from the basal ganglia?
Project on to the entire frontal lobe –> PriMC, premotor area, and supplementary motor area.
What does the intralaminar nuclei of the thalamus send output for from the basal ganglia?
It projects for additional motor relay.
What does the mediodorsal nucleus project output for?
For the limbic basal ganglia loop.
What does the superior colliculus receive output information for?
For the eye movement basal ganglia loop.
What does the direct pathway of the basal ganglia control?
Controls the start/initiation of movement.
What does the indirect pathway of the basal ganglia control?
Controls the inhibition of movement.
What region of the basal ganglia regulates the direct and indirect pathways by releasing dopamine?
The substantia nigra pars compacta.
What is the function of the Substantia Nigra Pars Compacta? What type if input is it for both pathways?
Modulates striatum activity through dopamine release to impact the direct and indirect pathways.
Excitatory to striatum in direct pathway.
Inhibitory to striatum in indirect pathway.
Effect = powerful decrease in suppression of thalamus by basal ganglia.
What is the action of acetylcholine in the basal ganglia?
Inhibits dopamine when appropriate and can quickly interrupt ongoing motor behavior in response to salient environmental stimuli.
What are the 2 neurotransmitters involved in the direct and indirect pathways?
GABA and Glutamate
What does the oculomotor loop of the basal ganglia control?
Higher control of eye movements.
Aids in spatial attention; initiates fast eye movements toward an object (saccadic movement)
What are the pre-frontal loops of the basal ganglia and what do they control?
- Goal-directed behavior loop = via GPi = decision making; goal directed behavior; planning; action selection; learning
- Social behavior loop = via SNpr = recognizes social cues; regulate self control; evaluates what information is relevant and irrelevant.
What is the limbic/emotion loop of the basal ganglia control?
Links emotions to cognitive and motor systems; reward seeking; outcome predictions
*receives dopaminergic input from the ventral tegmental area.
