Basal Ganglia

Question 1

What are the general functions of the basal nuclei?

Answer 1

Control of voluntary movement
- initiation of movement
- control of patterns of movement (timing and scaling of movements)
- programming and correcting movement while in progress

Control of posture
- righting reflex
- automatic associated movement

Control of muscle tone
- reticulospinal
- vestibulospinal

Reflexive muscular activity and eye movements

Control of other non motor functions
- consciousness, emotions and behaviour

Question 2

List the different basal ganglia

Answer 2

Caudate nucleus
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra
Thalamus

Question 3

Which structures does the stratium comprise of?

Answer 3

Caudate nuclues and putamen

Question 4

Which structures does the lentiform nucleus comprise of?

Answer 4

Putamen and globus pallidus

Question 5

What is the function of the substantial nigra?

Answer 5

It is a modulator of basal nuclei function

Question 6

Which substance is the substantia nigra have high levels of?

Answer 6

Neuromelanin

Question 7

What are the two functionally distinct regions of the substantia nigra and where are they positioned?

Answer 7

Pars compacta - dorsomedial (dopaminergic)
Pars reticulata - ventrolateral (GABAergic)

Question 8

What are the pathways in which the substantia nigra modulates motor movement through?

Answer 8

Direct pathway - facilitates the desired movements

Indirect pathway - inhibits undesired completing movements

Question 9

What is a common disorder of the substantia nigra? And how does this occur?

Answer 9

Parkinson’s disease
- loss of dopaminergic neurons of the substantia nigra

Question 10

What are primary motor symptoms and non motor symptoms of Parkinson’s disease?

Answer 10

Primary motor
- tremors (involuntary muscle contraction)
- akinesia/bradykinesia (lack of slowed movements)
- rigidity (stiff inflexible muscles)
- postural instability (stooped posture, loss of balance, falls
- gait (walking) difficulties (short shuffling and freezing gait)

Non motor symptoms
- sleep disturbances
- neurocognitive decline
- depression and anxiety
- anosmia or hyposmia