Basal ganglia and Cerebellum.

Question 1

Basal Ganglia consists of several nuclei. 3 in the Striatum and 2 in Globus Pallidus. What are they?

Answer 1

Striatum - Dorsal part - Caudate nucleus and putamen. Ventral part - nucleus acumbens.
Globus Pallidus - Internal and external.

Question 2

Name two related structures and they’re parts to the basal ganglia.

Answer 2

Substantia Nigra - pars compacta and pars reticula.

Subthalamic nucleus.

Question 3

Substantia nigra has two receptors. What are they and which is excitatory/inhibitory?

Answer 3

D1 -excitatory.

D2 - inhibitory.

Question 4

What are the 4 pathways in the basal ganglia?

Answer 4

Oculomotor, limbic, cognitive, motor.

Question 5

Are projections from the thalamus and subthalamic nucleus excitatory or inhibitory?

Answer 5

Excitatory.

Question 6

Are projections from the striatum and globus pallidus excitatory or inhibitory?

Answer 6

Inhibitory.

Question 7

There are two types of motor pathways, what are they? What are their jobs and what dopamine receptor is associated with each? Draw them out.

Answer 7

Direct - increases motor activity. D1 receptor activated on striatum.
Indirect - decreases motor activity. D2 receptor activated on the striatum.

Question 8

Cerebellum is divided into what 3 lobes?

Answer 8

Anterior, posterior and flocculondular lobe.

Question 9

There are 3 main cerebellar pathways. What are they?Describe each.

Answer 9

VESTIBULOCEREBELLUM - flocculondular lobe receives input from the vestibular nuclei and transmits info back and forth controlling the vestibulospinal tract. Controls reflexes, balance and stabiltiy.
CEREBROCEREBELLUM - lateral hemispheres receive input via pontine nuclei and transmit info back through dentate nucleus and thalamus to cortex. Controls planning and timing movements.
SPINOCEREBELLUM - vermis and intermediate zones receives input from the spinal cord and assist in movement control via projections to the fastigal nucleus and interposed nucleus. Integrates sensory input with motor commands to produce adaptive motor coordination.

Question 10

What is the role of the cerebellum?

Answer 10

Does not generate motor signals but modifies them to refine and correct movement via the 3 pathways.

Question 11

Injury results in what?

Answer 11

Less precise, uncontrolled and incorrectly timed movements. Problems with posture and balance on the side ipsilateral to the damage.