Voluntary Motion and Basal Ganglia

Question 1

Areas of the cortex needed for voluntary motion: (5)

Answer 1

Primary motor cortex
Supplementary motor cortex
Pre-motor cortex
Pre-frontal cortex
Parietal cortex

Question 2

Dorsal visual pathway

Answer 2

Axons from occipital cortex travel to parietal/frontal cortex.
Allows us to complete motor acts on visual input.

Question 3

What areas of the parietal cortex is info from the visual cortex related? (4)

Answer 3

V6A
PEc
MIP
VIP

Question 4

Role of VIP

Answer 4

To create a rough map of space around you and your target.

Question 5

From the VIP (parietal cortex) where is info sent?

What does this area do?

Answer 5

F4.

Creates a detailed map of the space around you. It’s neurons are more excited by proximity.

Question 6

From F4 to:

What is this area’s role? Where is it?

Answer 6

F2.

Receives visual info about where your arm is in space. It is in the pre-motor cortex.

Question 7

From occipital lobe to F2 in the reaching phase: (4)

Answer 7

Occipital lobe –> parietal cortex (VIP) –> F4 –> F2

Question 8

Role of the anterior intraparietal area and PFG

Answer 8

Has neurons that respond to seeing an object to grasp (visually dominant) and grasping the object (motor dominant) and both together (visuomotor dominant).

Question 9

Where do anterior intraparietal area and PFG relay info?

What is this area’s role?

Answer 9

F5.

It’s neurons fire with the goal of action (to drink, to carry, etc, NOT necessarily the grip, but the goal).

Question 10

What is the grasping pathway? (2 steps)

Answer 10

AIP and PFG to F5.

Question 11

Roles of pre-motor cortex (4)

Answer 11

Receives sensory info required to move and applies the rules that determine whether it is OK to move.
Identifies the intent of the motion and decides what motion to produce.

Question 12

2 divisions of the supplementary motor cortex and their jobs

SMC 3 main roles:

Answer 12

Supplementary motor area - postural control.

Pre-supplementary area - plans the motor program needed to make action occur.

SMC is involved in organizing, acquiring and executive control of motor skills.

Question 13

Role of primary motor cortex

Answer 13

Control specific, fine motor movements and is arranged in columns.

Question 14

Stimulation of an area in PMC that controls a fine motion may cause:

Answer 14

Contraction of a single muscle.

Question 15

Stimulation of an area in PMC that controls a more general motion may cause:

Answer 15

Contraction of a group of muscles.

Question 16

Which layer of the PMC receives sensory input?

Which layer becomes output for the corticospinal pathway?

Answer 16

Layer 4.

Layer 5.

Question 17

Why is there 2 sets of neurons in each column of the PMC?

Answer 17

One is needed to start the motion and another to maintain it.

Question 18

Neighboring columns in PMC control:

Answer 18

Related motions, not neighboring muscles.

Question 19

2 kinds of columns in PMC

Answer 19

On/off for agonist muscle.

On/off for antagonist muscle.

Question 20

Roles of cerebellum in motion (4)

Answer 20

Sequence of complex actions.
Correct force/direction.
Balance and eye movements.
Learning complex actions

Question 21

What part of the cerebellum plans future movements?

Answer 21

Vestibulocerebellum

Question 22

Inputs to vermis of spinocerebellum (4)

Outputs from vermis of spinocerebellum (2) going where?

Answer 22

Vestibular, visual, auditory, efferent copy (what brain sends to muscle).

Interpositus n. and fastigial n. to rubrospinal tract.

Question 23

What areas of the spinocerebellum correct motion ongoing motions and control ballistic motions?

Answer 23

Lateral regions of spinocerebellum.

Question 24

Inputs to paravermal region of spinocerebellum (2)

Outputs (1) going where?

Answer 24

Muscle afferent and efferent copy.

Interpositus nucleus to rubrospinal tract.

Question 25

Inputs to cerebrocerebellum (1)

Outputs (1) going where?

Answer 25

All regions of cortex.

Dentate going back to cortex.

Question 26

Input to vestibulocerebellum (1)

Outputs (1) going where?

Answer 26

Vestibular apparatus.

Fastigial nucleus to vestibular nuclei or directly to vestibular nuclei.

Question 27

2 big roles of basal ganglia

Answer 27

Initiation of movement.

Planning and programming of movement.

Question 28

What releases DA onto striatum?

Answer 28

Pars compacta of substantia nigra

Question 29

Receptors of direct pathway:
Excited by:
Allows:

Answer 29

D1
DA
Motion

Question 30

Receptors of indirect pathway:
Excited/inhibited by:
Function:

Answer 30

D2
+ EAA/ACh, - DA
Inhibit motion

Question 31

Direct pathway

Answer 31

1. SNPC releases DA within striatum (caudate, putamen).
2. Striatum releases GABA onto SNPR and GPi.
3. SNPR and GPi arew inhibited, which causes less GABA to be released onto thalamus and permits motion.

Question 32

Indirect pathway

Answer 32

1. SNPC releases DA onto striatum.
2. Striatum releases more GABA onto GPe.
3. GPe release less GABA onto subthalamic nucleus.
4. Subthalamic nucleus releases EAA to the SNPR and GPi.
5. SNPR and GPi release GABA onto thalamus.

Question 33

What happens w/ basal ganglia in Parkinson’s?

Answer 33

Trouble activating direct pathway.

Over-activation of indirect pathway.

Question 34

Interactions between frontal, parietal, SMC and basal ganglia determine;

Answer 34

IF motion will occur

Question 35

How does the muscle spindle not cause problems with voluntary motion?

Answer 35

The brain inhibits alpha-motoneurons and gamma-motoneurons in the antagonist muscle.