Basal Ganglia and Cerebellum

Question 1

Name 3 brain structures which receives widespread input from cortex and outputs back to cortex.

Answer 1

1. basal ganglia
2. cerebellum
3. hippocampus

Question 2

Which of the following is NOT a function of the cerebellum?

a) postural adjustments
b) representation of space
c) timing/cross muscle coordination

Answer 2

b) representation of space

Question 3

Which of the following disorders is not associated with basal ganglia damage?

a) Parkinson’s disease
b) Drug addiction
c) Obsessive compulsive disorders
d) Sleep Disorders

Answer 3

Sleep disorders

Question 4

Caudate and putamen together are called ________

Answer 4

striatum

Question 5

Substantia nigra has two sets of neurons with respect to the NT they are associated with:
________
________

Answer 5

DA, GABA

Question 6

There are 3 pathways from cortex to the internal segment of the globus pallidus: ________ , _________ , and ______

Answer 6

direct, hyperdirect, indirect

Question 7

The indirect pathway from cortex to the internal segment of the GP is mediated by which ganglial structure?

Answer 7

External segment of the globus pallidus (GPe)

Question 8

Which of the following structures are not involved in the cortex-basal ganglia-cortex network?

a) GPi
b) GPe
c) Cerebellum
d) Substantia Nigra
e) c and d

Answer 8

c) cerebellum

Question 9

What are the three cerebellar nuclei?

Answer 9

1. fastigial nucleus
2. interpositus nucleus
3. dentate nucleus

Question 10

What neuronal movements is the fastigial nucleus involved with?

Answer 10

eye mvmts./walking

Question 11

What localized inactivation is the fastigial nucleus associated with?

Answer 11

posture and gait instability

Question 12

What is the function of the fastigial nucleus?

Answer 12

postural adjustments

Question 13

What is the neuronal activity of the interpositus nucleus?

Answer 13

perpetuation of limb/body from holding position

Question 14

What is the localized inactivation of the interpositus nucleus?

Answer 14

tremor

Question 15

What is the function of the interpositus nucleus?

Answer 15

balance of agonist/antagonist muscles

Question 16

What is the neuronal activity of the dentate nucleus?

Answer 16

auditory and vision triggered movements

Question 17

What is the localized inactivation of the dentate nucleus?

Answer 17

reaction time delays; poor endpoint control

Question 18

What is the function of the dentate nucleus?

Answer 18

timing/cross muscle coordination

Question 19

The basal ganglia, hippocampus, and cerebellum all have ______ when information is flowing into them and then ________ when they are sending out output

Answer 19

convergence, divergence

Question 20

If you are trying to shoot a pigeon, you are using what part of the cerebellum? Why?

Answer 20

Dentate nucleus…because you need to coordinate the time and anticipation of where the pigeon will be so you can shoot it

Question 21

What is the cortex cerebellum cortex loop?

Answer 21

cerebral cortex -> pontine nuclie -> granule cells -> Purkinge cells -> cerebellar nuclei -> ventrolateral thalamus -> motor cortex

Question 22

What 2 parts of the cortex cerebellum cortex loop is inhibitory?

Answer 22

purkinje cells -> cerebellar nuclei

and

inferior olive -> purkinje cells

Question 23

Which dopamine receptor (D1 or D2) is associated with the direct pathway?

Answer 23

D1

Question 24

What does the D1 receptor do in the direct pathway?

Answer 24

opens up the gates and make neurons much more likely to excite

Question 25

What pathway is the D2 receptor associated with?

Answer 25

indirect pathway

Question 26

How does Parkinson’s start?

Answer 26

-lack DA input to straitum

Question 27

What does D2 do?

Answer 27

-depresses the neuron, input gets “cut off” so that the neuron’s depolarization is not as strong

Question 28

What are medium spiny neurons?

Answer 28

• a special type of GABA-ergic inhibitory cell representing 90-95% (depending upon species) of the neurons within the corpus striatum of the basal ganglia
• play a key role in initiating and controlling movements of the body, limbs, and eyes
• have D1 and D2 type dopamine receptors

Question 29

Purkinje cell dendrites are ____ and stacked like sheets of paper

Answer 29

2D

Question 30

Purkinje cells are _____

Answer 30

inhibitory

Question 31

Granule cells project ________ going through the sheets of Purkinje cells

Answer 31

perpendicularly

Question 32

Granule cells are _______

Answer 32

excitatory

Question 33

What do inferior olive neurons do?

Answer 33

fire strongly to unexpected outcome that deviates from a prepared muscle/action plan

Question 34

What does the inferior olive neuron do with the Purkinje cell?

Answer 34

• wraps inhibitory synapses around the Purkinje cells

- stops granule cells inputs when something unexpected happens

Question 35

Purkinje cells are _____ergic making them ______

Answer 35

GABAergic, inhibitory

Question 36

Lesioning the interpositus nucleus leads to posture instability. (TRUE/FALSE)

Answer 36

False.

It’s actually the fastigial nucleus

Question 37

Medium spiny neurons release dopamine. (TRUE/FALSE)

Answer 37

False, have DA receptors

Question 38

The cortex (excites/inhibits) the striatum, which (excites/inhibits) the globus pallidus external, which (excites/inhibits) the globus pallidus internal, which (excites/inhibits) the thalamus, which (excites/inhibits) the cortex.

Answer 38

The cortex EXCITES the striatum, which INHIBITS the globus pallidus external, which INHIBITS the globus pallidus internal, which INHIBITS the thalamus, which EXCITES the cortex.

Question 39

Explain briefly how the location of a dopamine synapse on a dendritic spine relative to a glutamate synapse may allow for modulation.

Answer 39

Glutamate is on the tip of the in the dendritic spine while Dopamine is at the base, leaving room for neuromodulation and mediation.