Basal Ganglia

Question 1

Functions of basal ganglia

Answer 1

1. Control muscle tone
2. Subconscious movements
3. Conscious + Voluntary movements
4. Arousal (consciousness)
5. Automated Associated movements

Question 2

Which 2 neurotransmitters used by basal ganglia are inhibitory?

Answer 2

GABA and Dopamine

Question 3

Corpus striatum communicates with the thalamus via two opposing pathways. State them and name which one is inhibitory and which one is excitatory.

Answer 3

Direct pathway is excitatory

Indirect pathway is inhibitory

Question 4

Describe the organization of basal ganglia.

Answer 4

Basal ganglia = Corpus striatum + Amygdala
Corpus striatum = Striatum + Globus pallidus
Striatum = Dorsal striatum (caudate nucleus + putamen) + Ventral striatum
Globus pallidus = Ventral Pallidus + GPi and GPe
Lentiform nucleus = globus pallidus + putamen

Question 5

Which cells in substantia nigra release dopamine?

Answer 5

Those in pars compacta

Question 6

Explain mechanism of Drug-Induced Parkinsonism

Answer 6

Hypertensive drugs strip dopamine from the basal ganglia

Question 7

Explain mechanism of Parkinsonism

Answer 7

Loss of dopamine means substantia nigra can’t communicate with Caudate nucleus and Putamen
loss of dopamine = overactivity of indirect pathway = excessive inhibition of movement

symptoms: festinant gait, hypertonic muscles