lecture 9: motor control

Question 1

function of the thalamus:

Answer 1

relay center for nervous system

Question 2

nuclei of the thalamus:
- anterior nucleus:
- ventral anterior:
- ventral lateral:
- centromedian:
- dorsal medial nucleus:

Answer 2

• limbic lobe (memory formation, emotional processing)
• supplementary motor area and frontal lobe (executive functioning)
• input from substantia nigra (controls body movements)
• gate keeper of thalamus
• role in limbic system and emotional processing

Question 3

what parts of the basal ganglia make up the striatum? lentiform?

Answer 3

• caudate, nucleus accumbens, putamen
• putamen & globus pallidus (external & internal segments)

Question 4

pars compacta is located in _______ region of substantia nigra.
pars reticulata is located in ________ region of substantia nigra

Answer 4

posterior
anterior

Question 5

what are general functions of the basal nuclei?

Answer 5

psychomotor functions (planning, coordination, execution)
cognition
emotion

Question 6

what are the nuclei that project in aka afferent pathway to basal nuclei system?

Answer 6

cerebral cortex
thalamus
substantia nigra, pars compacta (however, NOT strictly afferent)

Question 7

what are the nuclei that project out aka efferent pathway to basal nuclei system?

Answer 7

globus pallidus, internal segment to the thalamus for body motor functions

substantia nigra, pars reticulata to superior colliculus for eye movement

Question 8

_______ _________ is the basic pattern for neural circuit function

Answer 8

spatiotemporal innervation

Question 9

what is the gate keeper of the basal nuclei system? where is it mainly located?

Answer 9

medium spiny neuron
in striatum of basal nuclei

Question 10

Substantia Nigra Pars Compacta:

Functions: Involved in ________ both direct and indirect pathways.

Answer 10

modulating

Question 11

Efferent Pathways:

Globus Pallidus Internus (GPI): Receives signals from both pathways, playing a role in ________ thalamic activity.

Pars Reticulata (SNpr):
Functions: Sends inhibitory signals to _________, affecting overall motor output.

Answer 11

inhibiting
thalamus

Question 12

Direct Pathway
Goal: Activating _______ programs.
Convergence Projection: _______ medium spiny neurons —> single neuron in GPI

Analogy: Team effort—multiple players (MSNs) working together to initiate a specific movement.

Answer 12

“wanted”; multiple

Question 13

Indirect Pathway

Goal: Inhibiting _________ programs.
Divergence Projection: _________ medium spiny neuron -> Multiple neurons in GPI

Analogy: One player (MSN) saying, “Hold on, let’s not do that,” influencing others to stop certain movements.

Answer 13

“unwanted”; single

Question 14

cerebral cortex directly activate subthalamic nucleus is known as _________ pathway

Answer 14

hyper-direct

Question 15

parafasicular nucleus directly activate subthalamic uncles is known as _______ pathway

Answer 15

super-direct pathway

Question 16

Both the hyper-direct and super-direct pathways are major _____ excitatory input.

Answer 16

subthalamic

Question 17

________ Inhibition by GPI
Continuous, steady inhibition. Acts as a “brake” on thalamic activity for fine-tuning motor control.

Answer 17

Tonic

Question 18

Inhibition from Left Prefrontal Cortex
Essential for _______ Execution. Crucial for preventing _______ movements.

Answer 18

Functional; unwanted

Question 19

Parkinson’s Disease Pathophysiology is caused by 3 things:

total effect: Difficulty to Initiate _________ activities with extra ________ activities.

Answer 19

1. Death of Dopaminergic Neurons in SNpc
2. Decreased Excitatory Effects on Direct Pathway
3. Decreased Inhibitory Effects on Indirect Pathway

“Wanted”; Unwanted

Question 20

How does the decreased activation of the direct pathway impact intentional movements in hypokinetic disorders (parkinson’s)?

Akinesia is ______, rigidity is _______ and _______ to limb movement, and bradykinesia is ________ _of movement.

Answer 20

inhibits “wanted” programs (decreased/inhibited) , leading to difficulty initiating and executing purposeful movements.

no movement at all, stiffness/resistance and slowness.

Question 21

How does the decreased activation of the indirect pathway impact intentional movements in hyperkinetic disorders (huntingtons)?

Dyskinesia: unique _____ tremor (pill rolling)

Answer 21

inhibits “unwanted” program (increased/activated)

resting *movement not coordinated

Question 22

clinical management of Parkinson’s disease?

answer:
1. ________ therapy
2. ______ treatment
-drug?
3. _______ management: ______/_____ removal: unexpectedly ______. Deep brain _______

What is the most affective:

Answer 22

physical
medical; L-dopa (increases dopamine levels)
surgical; VA/VL; effective
stimulation

combination

Question 23

Which neurons are the ONES in charge of efferent functions in cerebral cortex cerebellar cortex, and striatum of basal nuclei?

Answer 23

GPI, SNpr

Question 24

Huntington’s disease = enlarged _______ ventricle and entirely lost ________ .
Starts to show around at what age? Indirect pathway lost at?

Answer 24

lateral; caudate
30-50 yrs. old
GPe

Question 25

Damage to subthalamic nucleus is known as ______. Unilateral or bilateral affects of the body?

Answer 25

hemiballismus