Basal Ganglia

Question 1

What does the basal ganglia do?

Answer 1

It regulates the extrapyramidal motor system which plays an important role in regulating voluntary movement on a subconscious level. Ex: arm swinging while walking

Question 2

Describe the direct pathway for facilitating voluntary movement

Answer 2

Cortex- (glu)>Striatum (gaba)->Globus pallidus-internal (gaba)–>thalamus (glu) –> cortex

dopamine from the SN activates D1 receptors

Question 3

Describe the indirect pathway for filtering involuntary movement

Answer 3

Cortex (glu) –>striatum (gaba) –>globus pallidus-external (gaba)–>subthalamic nucleus (glu)–>globus pallidus-internal (gaba)–>thalamus (glu)–>cortex

dopamine via SN activates the D2

Question 4

Basal ganglia dysfunction can lead to what kind of disorders?

Answer 4

both too much movement and too little movement

Question 5

What are symptoms of too much movement (hyperkinetic symptoms)?

Answer 5

tremors- often absent or mild at rest
hemiballismus-violent flinging movements of the arms and legs, almost always from lesion of contralateral subthalamic nucleus usually due to vascular causes such as hemorrhage or stroke
chorea-random and purposeless involuntary mvoements
dystonia-involuntary sustained muscle contractions
tics-repetitive, sterotyped, purposeless movement