Neural control of gait

Question 1

What are 2 major requirements for successful walking?

Answer 1

1. Production of basic locomotor rhythm

2. Equilibrium control of moving body

Question 2

In a spinal preparation, what were the effects to locomotion?

Answer 2

1. Near normal inter/intra limb rhythmic activation patterns
2. Functionally modulated reflex action
3. Requires an external stimulus to produce locomotion behaviour

Question 3

Each limb is controlled by a separate _____.

Answer 3

CPG

Question 4

Each CPG contains two groups of excitatory interneurons that directly project to and control the activity of ____ and _____ motor neurons respectively.

Answer 4

flexor; extensor

Question 5

Mutual _______ interconnections between the half-centres in the CPG ensure that only one centre can be active at a time.

Answer 5

inhibitory

Question 6

______ ______ = gait speed

Answer 6

rhythm generator

Question 7

_____ ______ = level of motor neuron activity

Answer 7

pattern formation

Question 8

The CPG both incorporates ________ control and _______ control.

Answer 8

descending; sensory

Question 9

In a decerebrate preparation, what 3 locomotor effects were seen?

Answer 9

1. Improved coordination of activation patterns compared to spinal prep
2. Weight support
3. Active propulsion

Question 10

What are the 3 main functions of the brainstem in regards to locomotion?

Answer 10

1. initiation of locomotion
2. postural control
3. control of muscle tone

Question 11

Stimulation of the mesencephalic locomotor regions (MLR) on decelerate cats produced __________ locomotion on a treadmill.

Answer 11

quadriped

Question 12

Neurons from the MLR activate the medial _______ formation which activates the spinal ________ system.

Answer 12

reticular; locomotor

Question 13

Increasing the intensity of the stimulation to the MLR leads to what 3 things?

Answer 13

1. increased propulsion force
2. increased speed
3. mode progression (walk, jog, run)

Question 14

Where is the reticular formation centred?

Answer 14

pons

Question 15

In regards to locomotion, what 3 things does the reticular formation influence?

Answer 15

1. movement
2. posture
3. muscle tone

Question 16

The ______ ______ integrates proprioceptive info from the legs with vestibular signals for the control of balance.

Answer 16

reticular formation

Question 17

The_________ and ________ tracts are direct connections from the brainstem to the spinal cord.

Answer 17

vestibulospinal; reticulospinal

Question 18

_________ pathways facilitate direct afferent feedback from sensory receptors related to locomotion to the cerebellum.

Answer 18

spinocerebellar

Question 19

Signals modulating locomotion sent to the brainstem from the cerebellum and relayed to the SC via the _______, ______ and ________ pathways which act directly on motor neurons to fine tune the movements according to the task.

Answer 19

vestibulospinal; rubrospinal; reticulospinal

Question 20

What is the major processing centre for locomotion in the brain?

Answer 20

cerebellum

Question 21

The ___________ is essential for accurate and coordinated movement,

Answer 21

cerebellum

Question 22

Damage to the cerebellum results in ________.

Answer 22

ataxia

Question 23

_________ = under/overshooting

Answer 23

dysmetria

Question 24

A decorticate preparation results in what two things in terms of locomotion ?

Answer 24

1. dynamic stability

2. Initiates reasonably normal goal-directed behaviour in neonatally decorticate animal

Question 25

_______ ______ brainstem-spinal cord pathways contribute to the automatic control of movements such as locomotion and postural tone.

Answer 25

basal ganglia

Question 26

The ______ ______ maintain appropriate postural muscle tone and modulate rhythmic stepping movements and initiate locomotion.

Answer 26

basal ganglia

Question 27

An _____ ______ = adaptable locomotor control system to meet goals of the animal in any environment

Answer 27

intact system

Question 28

The ______ ______ integrates info from the visual cortex to create adaptable gait.

Answer 28

motor cortex

Question 29

The _______ _______ loop is thought to be involved in locomotor movements that require volitional control, cognition and attention.

Answer 29

corticobasal ganglia

Question 30

What are the 3 major types of sensory control associated with movement?

Answer 30

1. Vision
2. Proprioception
3. Vestibular

Question 31

What are 4 roles in movement of the sensory controls?

Answer 31

1. Adaptation to changes in environment
2. Control of timing phase transition
3. Reinforcement of muscle activity
4. Interlimb coordination

Question 32

What is the stumbling corrective response?

Answer 32

Increased flexor activity resulting in increased toe clearance

Question 33

What are the two most important inputs when transitioning from stance to swing?

Answer 33

1. hip extension

2. limb unloading

Question 34

Limb loading activates _____ _____ _____ in extensor muscles leading to increased activation of extensor half centre.

Answer 34

GTO’s

Question 35

Limb unloading at terminal stance _______ activation of extensor half-centre and promotes transition to _______ half-centre.

Answer 35

decreases; flexor