Exam 2 Material: Quiz 4: Specifically Basal Ganglia

Question 1

SNc

Answer 1

substantia nigra pars compacta
dopamine!!
- without it, no voluntary movement

Question 2

SNr

Answer 2

substantia nigra pars reticulata

GABA

Question 3

GPe

Answer 3

globus pallidus external segment

GABA

Question 4

GPi

Answer 4

globus pallidus internal segment

GABA

Question 5

STN

Answer 5

subthalamic nucleus

Glutamate

Question 6

D1

Answer 6

dopamine D1 receptor (excitatory)

Question 7

D2

Answer 7

dopamine D2 receptor (inhibitory)

Question 8

GABA

Answer 8

inhibitory

Question 9

Glutamate

Answer 9

excitatory

Question 10

direct pathways involve what receptor?

Answer 10

D1

Question 11

indirect pathways involve what receptor?

Answer 11

D2

Question 12

Voluntary Movement: Direct Pathway Summary

Answer 12

D1 and D2 pathways converge at the thalamus and both pathways agree to movement

Question 13

Steps of Voluntary Movement: Direct Pathway

Answer 13

1. motor plan from the substantia nigra and motor cortex
2. SNc releases dopamine that binds to D1 receptors on GABA
3. GABA released into DNr and GPi
4. GABA will be off so no GABA will go to thalamus
5. thalamus disinhibited and glutamate is released to the motor cortex
6. basa ganglia approves the plan, goes to spinal cord, Ach released, movement!

Question 14

what neurotransmitter drives voluntary movement?

Answer 14

dopamine

Question 15

what neurotransmitter drives involuntary movement?

Answer 15

glutamate

Question 16

all direct pathways involve

Answer 16

GPi and SNr

Question 17

all indirect pathways involve

Answer 17

GPe, STN, GPi

Question 18

Steps of Voluntary Movement: Indirect Pathway

Answer 18

1. SNc sending Dopamine to the D2 receptor on the GABA neuron
2. D2 not releasing GABA to GPe, so GPe is disinhibited and turned on
3. GPe releases GABA to STN, inhibiting STN
4. STN not sending glutamate to GPi
5. GPi turned off and can not send glutamate to the thalamus
6. thalamus disinhibited, turned on, glutamae to motor cortex, Ach release, movement

Question 19

Steps of NO initiated movement: direct pathway

Answer 19

1. D1 receptors turned on on GABA neurons
2. GABA released, inhibiting SNr and GPi so they can not send GABA to thalamus
3. thalamus disinhibited, turns on and send glutamate to motor cortex
4. signal spinal cord and release Ach, get little movement

Question 20

Steps of NO initiated movement: indirect pathway

Answer 20

1. D2 releases GABA which inhibits GPe
2. GPe can not send to STN, so STN is disinhibited and turned on
3. STN sends glutamate to GPi which releases GABA to the thalamus
4. this inhibits the thalamus, so it can not release glutamate to motor cortex
5. NO movement

Question 21

ultimately motor behavior determined by…

Answer 21

balance between direct/indirect striatal outputs

Question 22

2 diseases that directly influence the basal ganglia

Answer 22

huntington’s and parkinson’s disease

Question 23

basal ganglia smooth movements before or during the movement?

Answer 23

before

Question 24

cerebellum smooth movements before or during the movement?

Answer 24

during