Basal Ganglia

Question 1

BG is Embryologically derived mainly from the_______. Components of it are also derived from the

Answer 1

telencephalon

diencephalon and the mesencephalon.

Question 2

Location of BG

Answer 2

Located beneath the cerebral cortex and lateral to the dorsal thalamus

Question 3

Striatum or neostriatum is composed of

Answer 3

• Caudate nucleus

* Putamen

Question 4

Globus pallidus or paleostriatum made of;

Answer 4

• external or lateral segment (GPe)

* internal or medial segment (GPi)

Question 5

Putamen and Globus Pallidus together are also known as the

Answer 5

lentiform or lenticular nucleus

Question 6

Substantia nigra (in the midbrain) has two parts:

Answer 6

• pars compacta (SNc; dorsal): dopaminergic

* pars reticulata (SNr; ventral): GABAergic

Question 7

pars compacta (SNc; dorsal) is

Answer 7

dopaminergic

Question 8

pars reticulata (SNr; ventral) is

Answer 8

GABAergic

Question 9

Nucleus accumbens is also the

Answer 9

Ventral striatum

Question 10

Arterial supply of BG
Anterior cerebral artery–>
Middle cerebral artery–>
Posterior communicating artery

Answer 10

ACA–>medial staite artery

MIddle cerebral artery–> lateral striate and anterior choriodal artery

Question 11

The Cortex NT

Answer 11

glutamate

Question 12

The straitum (caudate and putamen) have these NTs

Answer 12

Ach, GABA, substance P, enkephalin

Question 13

DIRECT PATHWAY:

Answer 13

The Striatum inhibits the inhibitory output from GPi and SNr to the Thalamus. Thus, the Thalamus is disinhibited (released from the inhibitory influence of GPi and SNr, i.e., excited), so it can excite the Cortex. Thus, MOVEMENT IS FACILITATED.

Question 14

Direct Pathway: The Striatum_______ the inhibitory output from GPi and SNr to the Thalamus. Thus, the Thalamus is______ (released from the inhibitory influence of GPi and SNr, i.e., excited), so it can_____ the Cortex. Thus, MOVEMENT IS________.

Answer 14

inhibits
disinhibited
excite
FACILITATED

Question 15

INDIRECT PATHWAY:

Answer 15

This pathway involves GPe and the Subthalamic nucleus (hence, Indirect). The Striatum inhibits the inhibitory output from GPe to the Subthalamic nucleus. The Subthalamic nucleus (released from the inhibitory influence of GPe) can excite the GPi and SNr to INHIBIT the Thalamus. The inhibited Thalamus is less able to excite the Cortex, so MOVEMENT IS INHIBITED

Question 16

This pathway involves _________(hence, Indirect). The Striatum_______ the inhibitory output from GPe to the Subthalamic nucleus. The Subthalamic nucleus (released from the inhibitory influence of GPe) can_____ the GPi and SNr to________ the Thalamus. The inhibited Thalamus is less able to excite the Cortex, so _________

Answer 16

GPe and the Subthalamic nucleus 
 inhibits
excite
INHIBIT
MOVEMENT IS INHIBITED

Question 17

Nigrostriatal pathway:
NT?
facilitates movement by acting on

Answer 17

dopaminergic;

both direct and indirect pathways.

Question 18

Dopamine affects

Answer 18

2 different types of output neurons in the striatum:

Question 19

Neurons with D1 dopamine receptors:

Answer 19

• Involved in exciting the Direct Pathway

* Hence, facilitate movement

Question 20

• Involved in exciting the Direct Pathway

* Hence, facilitate movement

Answer 20

D1 dopamine receptors

Question 21

Neurons with D2 dopamine receptors:

Answer 21

• Involved in inhibiting the Indirect Pathway (which inhibits movement) i.e., inhibiting the inhibitory pathway
• Inhibiting the inhibitory pathway leads to disinhibition of the thalamus
• Facilitate movement

Question 22

• Involved in inhibiting the Indirect Pathway (which inhibits movement) i.e., inhibiting the inhibitory pathway
• Inhibiting the inhibitory pathway leads to disinhibition of the thalamus
• Facilitate movement

Answer 22

D2 dopamine receptors

Question 23

D2 dopamine
• Involved in______ the Indirect Pathway (which inhibits movement) i.e., inhibiting the inhibitory pathway
• Inhibiting the inhibitory pathway leads to________ of the thalamus
•________ movement

Answer 23

inhibiting
disinhibition
Facilitate

Question 24

end result of dopamine on both the Direct and Indirect pathways is the

Answer 24

FACILITATION OF MOVEMENT.

Question 25

_______is the neurotransmitter of intrinsic neurons in the striatum.

Answer 25

Acetylcholine

Question 26

Do cholingergic neurons project outside of the striatum

Answer 26

nope

Question 27

They inhibit striatal neurons of the Direct Pathway

Answer 27

cholinergic neurons in striatum

Question 28

Affect of cholinergic neurons in striatum on Indirect pathway

Answer 28

They excite striatal neurons of the Indirect Pathway

Question 29

effects result in the INHIBITION OF MOVEMENT.

Answer 29

Aceytycholine

Question 30

Cholinergic neurons in the striatum: effects result in the

Answer 30

INHIBITION OF MOVEMENT

Question 31

Extrinsic inputs to the basal ganglia terminate mainly in the

Answer 31

striatum.

Question 32

Where do extrinsic inputs to BG come from

Answer 32

``` cerebral cortex (motor, sensory, association and limbic)~ topologically organized Intralaminar nuclei of the thalamus: also topographically organized ```

Question 33

Extrinsic outputs from the basal ganglia arise mainly from

Answer 33

globus pallidus and substantia nigra, pars reticulate (SNr).

Question 34

Extrinsic outputs from the basal ganglia arise mainly from the globus pallidus and substantia nigra, pars reticulate (SNr). Both of them are_____.

Answer 34

GABAergic

Question 35

Extrinsic outputs from the basal ganglia arise mainly from the globus pallidus and substantia nigra, pars reticulate (SNr). Both of them are GABAergic. They project to:

Answer 35

* Motor nuclei of the thalamus | * Superior colliculus of the midbrain

Question 36

3 connection within the BG

Answer 36

Striatum (caudate and putamen) Subthalmic nucuels substantia niagra

Question 37

How is the Basal ganglia involved in regulation of movement

Answer 37

Involved in the regulation of movement: through direct and indirect connections with the cerebral cortex, the basal ganglia influence descending motor systems

Question 38

What role does the BG have in the extrapyramidal motor system?

Answer 38

Forms the major component of the extrapyramidal motor system; however, there is extensive interconnections and cooperation between the extrapyramidal and the pyramidal systems in the control of movement.

Question 39

Three general functions of the BG?

Answer 39

Involved in the control of eye movements and in the memory of orientation in space. Contributes to cognition. Related to limbic functions.

Question 40

Disorders of the basal ganglia is usually a disruption of

Answer 40

transmitter metabolism

Question 41

Abnormal movements are commonly caused by a release of the system from

Answer 41

inhibition

Question 42

Symptoms of BG dysfunction

Answer 42

Involuntary movements: tremor at rest, athetosis, chorea, ballism, and dystonia Akinesia and bradykinesia Changes in posture and muscle tone Muscle rigidity

Question 43

Degeneration of dopaminergic cells in SNc | • Tremor at rest, rigidity, and bradykinesia

Answer 43

Parkinsons Diseaese

Question 44

Parkinsons is degeneration of __________ in the __________

Answer 44

dopaminergic | SNc

Question 45

Degeneration of cholinergic and GABAergic neurons in the striatum

Answer 45

Huntingtons

Question 46

Genetics of Huntingtons

Answer 46

inherited; mutation in chromosome 4 causes numerous CAG repeats (encodes for glutamine)

Question 47

symptoms of Huntingtons

Answer 47

Chorea, athetosis, and dystonia

Question 48

Tardive dyskinesia:

Answer 48

* Results from long term use of antipsychotic agents, which block dopamine transmission * Involuntary movements, especially of the face and tongue

Question 49

long term use of anti-psychotics that block dopamine transmission can cause

Answer 49

tardive dyskenesia

Question 50

Tardive dyskinesia usually affects

Answer 50

face and tongue (get involuntary movements)

Question 51

Hemiballismus:

Answer 51

* Lesion of the subthalamic nucleus | * Violent “ball-throwing” movements of the contralateral arm

Question 52

Lesion of the subthalamic nucleus

Answer 52

Hemiballismus

Question 53

* Lesion of the subthalamic nucleus | * Violent “ball-throwing” movements of the contralateral arm

Answer 53

Hemiballismus

Question 54

Cerebellum has______ input from the spinal cord | BG has -_____

Answer 54

Direct | None

Question 55

Cerebellum and BG have ______direct output to the spinal cord

Answer 55

no

Question 56

Connections with the brain stem

Answer 56

Cerebellum

Question 57

- Connects with and part of it is in the brain stem

Answer 57

BG

Question 58

Cerebellum has _____ Input from the cortex | BG has _____ _input from the cortex

Answer 58

indirect | Direct

Question 59

Both Cerebellum and BG projects via______ to the cortex

Answer 59

thalamus

Question 60

Output from cerebellum is ________ | Output from BG is _______

Answer 60

Excitatory | inhibitory

Question 61

Coordinates execution of movements: compares intended with executed

Answer 61

cerebellum

Question 62

Planning and execution of complex motor strategies: amplitude & velocity of movements

Answer 62

BG

Question 63

Cerebellar Lesion:______ symptoms | BG Lesion:

Answer 63

ipsilateral often contralateral symptoms, but can be bilateral

Question 64

Symptoms associated with Cerebellar lesion:

Answer 64

Ataxia, impaired balance, intentional tremor

Question 65

Symptoms associated with BG lesion

Answer 65

Too much or too little movements, tremor at rest