Basal Ganglia Lecture Notes

A collection of flashcards covering key concepts about the Basal Ganglia, their structure, function, pathways, disorders, and treatments.

What are the main components of the Basal Ganglia?

Striatum (caudate nucleus + putamen), Globus pallidus (internal and external), Substantia nigra, Subthalamic nucleus.

What is the main input structure of the Basal Ganglia?

The Striatum, which receives input from the cortex and brainstem.

How is the output from the Basal Ganglia primarily characterized?

The output is primarily inhibitory and tonically active, preventing unintended movements.

What are the two groups of projection neurons in the Striatum?

Direct pathway (Striatum → GPi → thalamus) and Indirect pathway (Striatum → GPe → STN → GPi → thalamus).

What is the role of medium spiny neurons in the Basal Ganglia?

They are the main output neurons of the Striatum, projecting to the globus pallidus and substantia nigra.

What is the effect of dopamine on the direct pathway of the Basal Ganglia?

Dopamine activates D1 receptors, enhancing the direct pathway, which facilitates movement.

What is the function of acetylcholine in the Basal Ganglia?

Acetylcholine inhibits striatal neurons of the direct pathway and excites striatal neurons of the indirect pathway, modulating motor activity.

What are the primary disorders associated with the Basal Ganglia?

Hyperkinesia (e.g., Huntington’s disease) and Hypokinesia (e.g., Parkinson’s disease).

What causes Parkinson’s disease?

Degeneration of dopaminergic neurons in the substantia nigra pars compacta.

How does L-Dopa treatment aid in Parkinson’s disease?

It increases the amount of dopamine in surviving dopaminergic neurons, alleviating symptoms.