Cortical Control of Movement Lec21

Question 1

A disproportionate area of the motor cortex is devoted to control of the ___ and ___

Answer 1

hand and fingers

Question 2

The “indirect pathway” from cortex to spinal cord enables ___ postural adjustments.

Answer 2

feed-forward

Question 3

The “indirect pathway” from cortex to spinal cord plays an important role in ___

Answer 3

weight shifts

Question 4

Functionally similar and non-adjacent columns are interconnected by interneurons within the____.

Answer 4

motor cortex.

Question 5

Cortical areas that plan and initiate motor sequences comprise several ___ distinct but highly interconnected regions.

Answer 5

functionally

Question 6

Proper motor control requires (3)

Answer 6

timing, position, and physical characteristics of body and muscles

Question 7

brainstem centers are involved with basic movements and ___ conrol

Answer 7

postural

Question 8

____ Motor Pathways can be direct or indirect:

Answer 8

Descending

Question 9

Direct descending motor pathway is from cortex straight to ___

Answer 9

LMNs

Question 10

Indirect descending motor pathway synapse on

Answer 10

brainstem interneurons

Question 11

both direct and indirect synapse on the

Answer 11

ventral horn of the spinal cord

Question 12

the proportion of direct vs. indirect terminations varies between species and changes with ___

Answer 12

age/ development

Question 13

indirect pathway UMNs –> ___ –> interneurons

Answer 13

anteromedial white matter (rubrospinal and extrapyramidal tracts)

Question 14

indirect pathway Indirect: brainstem UMNs –> anteromedial white matter (rubrospinal and extrapyramidal tracts) –> interneurons –> ___ muscles

Answer 14

axial and proximal muscles

Question 15

Long distance interneurons are medial or ventral

Answer 15

medial

Question 16

Long distance interneurons are medial, go to ___ muscles

Answer 16

proximal

Question 17

Short distance interneurons are lateral, go to ___ muscles

Answer 17

distal

Question 18

direct pathway goes to ___ muscles

Answer 18

distal

Question 19

name 4 indirect pathways

Answer 19

1. tectospinal
2. reticulospinal
3. rubrospinal
4. vestibulospinal

Question 20

tectospinal is involved with__ and __

Answer 20

axial and midline body orientation

Question 21

rubrospinal is involved with___ controls

Answer 21

distal control, mainly arm flexion

Question 22

vestibulospinal modifies

Answer 22

reflexes, central pattern generators

Question 23

which indirect pathways modify reflexes?

Answer 23

vestibulo and reticuno

Question 24

___ pathway modifies antigravity muscles

Answer 24

reticulospinal

Question 25

example of direct pathways

Answer 25

Ventral & Lateral Corticospinals (to body), and Corticobulbar (to face)

Question 26

Most direct corticomotor innervation comes from the\_\_\_

Answer 26

primary motor cortex (M1)

Question 27

in the cortex **Motor units** are controlled by\_\_\_ or ___ cells

Answer 27

Betz cells or other large, non-Betz pyramidal cells

Question 28

Lateral premotor cortex is involved in

Answer 28

selection of motor responses based one xternal cues

Question 29

Medial premotor cortex is involved with

Answer 29

learned sequences, repsonse to intenral cues

Question 30

supplementary mtoor area and the cingulate motor area are found in the

Answer 30

medial premotor cortex

Question 31

pre-sma is invovled with

Answer 31

learning sequencies

Question 32

3 association areas?

Answer 32

**1. Pre-SMA: l**earning sequences **2. Parietal and Temporal cortex** - Dorsal pathway - Ventral pathway **3. Prefrontal cortex**: decision making, working memory, monitoring outcomes

Question 33

\_\_\_\_ areas are not “cortical motor areas” even though they’re in the cortex.

Answer 33

association

Question 34

Technically, a **“cortical motor area”..**. (4)

Answer 34

1. projects **from M1 to motor neurons in the spinal cord,** either directly or indirectly 2. contains **Betz or Betz-like cells** that project **from layer V;** 3. can be stimulated **to produce movements of discrete muscles or muscle groups;** 4. display**s changes in activity related** to **parameters of movement**.

Question 35

face is lateral or medial?

Answer 35

lateral

Question 36

lower face has ___ innervation?

Answer 36

unilateral

Question 37

upper face has ___ innervation

Answer 37

bilateral

Question 38

) Individual muscles are represented in ___ cortex locations

Answer 38

multiple (this is convergence)

Question 39

Individual ____ influence multiple motor neuron pools

Answer 39

neurons

Question 40

all the LMNs of a motor neuron pool synapse with the same \_\_\_

Answer 40

UMN

Question 41

\_\_\_\_ lesion in monkey = difficulty getting food from the tube.

Answer 41

Lateral corticospinal tract

Question 42

For epilepsy, can map motor cortex via \_\_, then resect “hot” regions or make sub-pial incisions to preserve motor function

Answer 42

direct brain stimulation

Question 43

Cortical motor neurons can code for (3)

Answer 43

muscle activity, force, or direction.

Question 44

50% of M1 neurons have “movement-like activity”: neuron fires based on which _____ the hand is moving, regardless of which muscles are being used

Answer 44

direction

Question 45

3 tasks that must be accomplsihed for proper motor control?

Answer 45

1. motor system must produced ACCURATELY TIMED COMMANDS to muscle groups 2. motor system must take into account CURRENT POSITION OF BODY and DISTRIBUTION OF MUSCLE MASS 3. motor system must take into account/compensate for the PHSYCIAL CHARACTERISTICS OF THE BODY AND MUSCLES

Question 46

the motor sysytem is ___ organized

Answer 46

heirarchially

Question 47

lowest levels in motor system heirachry accomplish

Answer 47

most automatic behaviors

Question 48

highest levels in motor system heirarchy are concerned with

Answer 48

complex planning and selection (at the expense of time!)

Question 49

motor system is ___ segregated

Answer 49

functionally

Question 50

\_\_\_\_ local circuit neurons control more dextrious mvoement

Answer 50

short distance (lateral)

Question 51

definition of cortical motor area has to project to (2)

Answer 51

1. motor neurons in the spinal cord 2. primary motor cortex

Question 52

definition of cortical motor area can be stimulated at low thresholds to poduce movements of \_\_\_

Answer 52

discrete muscle or muscle groups

Question 53

definition of cortical motor area has to display changes in activity related to

Answer 53

paramters of movement

Question 54

microstim. studies showed there are mutliple representations of each body part even

Answer 54

within a single motor area

Question 55

microstim. studies showed that cells with simialr targets are \_\_\_\_

Answer 55

not adjacent to one another (fractured somatopy)

Question 56

microstim. studies showed columns of functionally related neurons are connected by

Answer 56

horizontal connections

Question 57

METHOD FOR SPIKE TRIGGERED AVERAGING:1) Record from a single upper motor neuron (#1) and a muscle whose lower motor neuron ## Footnote (#2) may be influenced by it 2) Average EMG from cell #2’s muscle for brief time after each spike (discharge) of cell #1 3) If cell #1 synapses with cell #2, there will

Answer 57

be a change in EMG (Increase=Excitatory, Decrease=Inhibitory)

Question 58

**SPIKE TRIGGERED AVERAGING allows you to to establish connectivity maps between 1 cortical motor neuron and \_\_\_**

Answer 58

multiple muscles that it might innervate

Question 59

if you record from an i\_\_\_, there is a preferred direction of movement

Answer 59

ndividual cortical cell