Basal Ganglia

Question 1

Basal ganglia functions

Answer 1

Regulate movement
Process info related to emotion, motivation, cognition

Question 2

How does the basal ganglia regulate movement

Answer 2

Role in initiation
Switching motor programmes
Inhibit antagonistic and unnecessary movements
Regulate force

Question 3

What makes up the dorsal striatum

Answer 3

Caudate nucleus + putamen

Question 4

What makes up the lentiform nucleus

Answer 4

Putamen + globus pallidus

Question 5

What separates the putamen and thalamus

Answer 5

Internal capsule

Question 6

Are the basal ganglia grey matter or white matter

Answer 6

Grey

Question 7

What shape is the caudate nucleus and what lobes if it in

Answer 7

C shape
Head in frontal, tail in temporal

Question 8

What shape are the putamen nuclei

Answer 8

Round

Question 9

2 parts of the globus pallidus and their functions

Answer 9

External - relay information between other basal ganglia nuclei and internal globus pallidus
Internal - sends output to thalamus

Question 10

Internal capsule

Answer 10

White matter structure separating lentiform nucleus and mandate nucleus from thalamus

Question 11

Internal capsule function

Answer 11

Carries info past basal ganglia

Question 12

What basal ganglia function involves the subthalamic nucleus and substantia nigra

Answer 12

Motor function

Question 13

Main blood supply of basal ganglia

Answer 13

Lenticulostriate arteries - body of caudate + putamen
Anterior cerebral artery - head of caudate + putamen + globus pallidus
Anterior choroidal artery - int globus pallidus
Posterior cerebral artery - substantia nigra, subthalamic nucleus

Question 14

Where do the lenticulostriate arteries branch from

Answer 14

Middle cerebral artery

Question 15

What structure receives all inputs to the basal ganglia

Answer 15

Dorsal striatum

Question 16

What brain structures send inputs to the basal ganglia

Answer 16

Cerebral cortex
Substantia nigra pars compacta

Question 17

What pathway brings inputs from the cerebral cortex to the basal ganglia

Answer 17

Corticostriatal pathway

Question 18

What pathway brings dopaminergic inputs

Answer 18

Nigrostriatal pathway

Question 19

What are the most abundant type of neurones in the dorsal striatum

Answer 19

Medium spiny neurones

Question 20

Why do medium spiny neurons have large dendritic trees

Answer 20

Receive a lot of info from different brain regions

Question 21

What types of convergent inputs go to the medium spiny neurons

Answer 21

Glutamergic
Dopaminergic
GABAergic

Question 22

Where are the medium spiny neurones

Answer 22

Striatum

Question 23

Output zone of basal ganglia

Answer 23

Globus pallidus ext and int
Substantia nigra pars reticula

Question 24

Where do the basal ganglia output zones project to

Answer 24

GPe -> subthalamic nucleus
GPi -> ventral anterior/ ventrolateral thalamic nuclear complex
SNr -> superior colliculus

Question 25

Are inputs to the basal ganglia convergent or divergent

Answer 25

Convergent

Question 26

3 loops between the cortex, basal ganglia, and thalamus

Answer 26

Motor loop Associative loop Limbic loop

Question 27

Where are the upper motor neurones influenced by the GPi and SNr

Answer 27

GPi - frontal cortex (via thalamus) SNr - superior colliculus

Question 28

Disinhibition

Answer 28

Excitation by double inhibition

Question 29

Are glutamate and GABA excitatory or inhibitory

Answer 29

Glutamate excitatory GABA inhibitory

Question 30

Are inputs and outputs of the striatum excitatory or inhibitory

Answer 30

Inputs excitatory Outputs inhibitory -> disinhibition of thalamus

Question 31

When the striatum is excited, are the GP, VA/VL complex of the thalamus, and UMNs in the cortex excited or inhibited in the direct pathway

Answer 31

GP inhibited VA/VL of thalamus disinhibited (excited) UMNs excited

Question 32

Direct pathway effect on thalamus

Answer 32

Excites motor thalamus by removing tonic inhibition from GPi

Question 33

Direct pathway

Answer 33

Sensory+assoc cornices -> dorsal striatum -> GPi -> motor thalamus -> supplementary motor cortex