Midterm 2 - Unit 5 Lecture 2

Question 1

function of Basal Ganglia

Answer 1

Used in the planning and control of complex movements
Organizes sequencing of movements

Question 2

does the Basal Ganglia act directly or indirectly to lower motor neurons

Answer 2

indirectly

Question 3

is the Basal ganglia involved with the SMA or PMA

Answer 3

SMA
Programs self-initiated movements
Self-initiated movement rather than stimulus triggered movement
Control of habitual, skill-based behaviours

Question 4

The basal ganglia selectively activates some movements while suppressing others. true or false

Answer 4

True

Question 5

the basal ganglia inhibits unwanted movements and releases this inhibition to trigger movement. True or false

Answer 5

true

Question 6

what are the Group of nuclei at ‘base’ of cerebral cortex:

Answer 6

Caudate
Putamen
Globus Pallidus
Substantia Nigra
Subthalamic Nucleus

Question 7

what makes up the striatum

Answer 7

Caudate and Putamen

Question 8

what makes up the lenticular nucleus

Answer 8

Globus pallidus and putamen

Question 9

what is the shape/structure of the caudate

Answer 9

C shaped structure

Question 10

how is the caudate divided

Answer 10

Divided into three parts:
Head, body and tail

Question 11

What part of the brain is the putamen in?

Answer 11

The putamen is a round structure located at the base of the forebrain (telencephalon)

Question 12

how are the putamen and caudate connected

Answer 12

Cellular bridges to caudate nucleus

Question 13

what are the two segments of the Globus Pallidus

Answer 13

Internal, medial component; GPi
External, lateral component; GPe

Question 14

GPi is one of the major outputs of the basal ganglia. true or false

Answer 14

true

Question 15

the Subthalamic Nucleus is inferior to which structure

Answer 15

thalamus

Question 16

what is the shape of the Subthalamic Nucleus

Answer 16

‘Spindle’ or ‘lens’ shaped

Question 17

the Subthalamic Nucleus communicates with the

Answer 17

Globus Pallidus

Question 18

what are the two segments of the Substantia Nigra

Answer 18

Pars compacta: more dorsal, contains darkly pigmented dopaminergic neurons

Pars reticulata: more ventral, involved in output, inhibits thalamus

Question 19

what is the input nuclei associated with the Basal ganglia

Answer 19

Striatum: Putamen and Caudate

Question 20

the basal ganglia receive Inputs from widespread areas of Cerebral Cortex including

Answer 20

Sensory areas
Motor areas
Association areas
thalamus

Question 21

what is the output nuclei associated with the Basal ganglia

Answer 21

Globus pallidus internal segment
Substantia nigra pars reticulata

Question 22

does the Basal Ganglia Output have an inhibitory or an excitatory effect

Answer 22

inhibitory, GABA

Question 23

where does the Basal Ganglia output to

Answer 23

Thalamus
Superior colliculus

Question 24

The basal ganglia output nuclei have inhibitory projections to ______________

Answer 24

thalamus

Question 25

BG modulates this tonic inhibitory output through two main pathways:

Answer 25

Direct and Indirect

Question 26

At rest we know the Globus Pallidus internal has an _____________output and it talks to the ____________

Answer 26

inhibitory, thalamus

Question 27

what happens at rest in the Basal Ganglia Pathways

Answer 27

At rest GPi and SNpr they are ticking away at some resting discharge rate And this inhibition is causing the thalamus which has an excitatory connection with the cortex, its being inhibited = less excitatory effect

Question 28

what is the direct pathway of Basal Ganglia

Answer 28

circuit best known for its hypothesized role in movement

Question 29

The direct pathway, its net outcome is to

Answer 29

increase that thalamus output

Question 30

how does the direct pathway increase that thalamus output

Answer 30

by reducing the Globus Pallidus internal segment doing so reduces its inhibitory effect

Question 31

The direct pathway starts with the ______________ and produces an ____________ output

Answer 31

cortex, excitatory

Question 32

(Direct pathway) From the cortex, the ______________which is the main input nuclei, has an _______________effect on the ____________________

Answer 32

striatum, inhibitory effect, GPi

Question 33

how does the striatum inhibiting the GPi reduce the inhibitory effects on the thalamus

Answer 33

because we know the GPi inhibits the thalamus, so because we’re inhibiting the GPi, we’re having less inhibitory effect on the thalamus

Question 34

what is disinhibition

Answer 34

removing the inhibition on the thalamus

Question 35

what happens when you take away that inhibition on the thalamus

Answer 35

you can increase the excitatory effect on the cortex, which will increase the descending drive

Question 36

does the basal ganglia have indirect or direct effect on lower motor neurons

Answer 36

indirect

Question 37

the direct pathway is all about ______________the lower motor neuron activity

Answer 37

increasing

Question 38

The indirect pathway is all about ____________

Answer 38

decreasing thalamus output

Question 39

how does the indirect pathway decrease thalamus output

Answer 39

when we increase that GPi, this effect is stronger, there is more inhibition on that thalamus 1.cortex excites striatum 2.striatum inhibits the GPe 3. GPe has an inhibitory effect on the STN(subthalamic nucleus) 4. the STN has an excitatory connection on the GPi, 6. GPi and has an inhibitory connection on the thalamus which is being strengthened

Question 40

what does a greater inhibition on the Thalamus do

Answer 40

means we can’t excite the cortex as much It eventually leads to a decreased descending drive

Question 41

what are the Effect of Dopamine on these pathways

Answer 41

Dopamine allows you to produce the movement that’s desired, turning down the brake and turning up the gas

Question 42

name a Basal Ganglia Dysfunction

Answer 42

Parkinson disease

Question 43

what causes parkinson disease

Answer 43

Caused by neuron death in substantia nigra loss of dopamine

Question 44

What happens to the basal ganglia in Parkinson's?

Answer 44

Disrupts normal modulation of BG output So all of a sudden you can’t turn off the gas and theres too much break

Question 45

what are the Classic Symptoms of Parkinson’s Disease

Answer 45

Akinesia and Bradykinesia Difficulty initiating movement and slow small movements Resting tremor Rhythmic oscillation in distal limbs (usually hand or upper extremity) Rigidity Increased muscle tone and stiffness: “Lead pipe” or “cog-wheel” rigidity Postural instability Leading to unsteady gait

Question 46

Other Symptoms of Parkinson’s Disease (Posture and gait related)

Answer 46

Stooped posture Shuffling gait with freezing and difficulty turning Diminished arm swing while walking

Question 47

Other Symptoms of Parkinson’s Disease

Answer 47

Micrographia and Hypophonia Diminished facial expressions

Question 48

what is another Basal Ganglia Disorder that we learned

Answer 48

Huntington’s Disease

Question 49

what is Huntington’s Disease

Answer 49

Hyperkinestic movement disorder Degeneration of striatal neurons in caudate and putamen Neurons of indirect pathway more severely affected Not enough inhibition (for the unwanted movements)

Question 50

symptoms of Huntington’s Disease

Answer 50

Hyperkinetic movements: Chorea and dystonia