Basal ganglia

Question 1

What is the basal ganglia comprised of three structures?

Answer 1

Striatum: caudate nucleus putamen
Globus pallidus

Question 2

What is the important input output loop in the BG?

Answer 2

Motor cortex and all four lobes of the cortex and thalamic nuclei sends INPUT through the striatum

Output is usually through the Globus Pallidus and goes out to the thalamus / cortex amd cortical motor areas in the frontal lobe

Hence, a loop

Question 3

What are the functions of BG? How are they related to Parkinson’s disease and Huntington’s chorea?

Answer 3

• Movement: there is hypokinesia in Parkinson’s, reduced voluntary movements e.g. trembling while adding sugar to coffee
• Initiation of voluntary movement (what we want eg typing and not reflexes): hyperkinesia, e.g. jerky moments of dance

=> abnormality in dopamine production in BG