Exam Two - Locomotion

Question 1

What are the structures of the nervous system that control locomotion

Answer 1

• central pattern generator
• peripheral receptors and afferents
• locomotor regions in the brainstem
• cerebral cortex

Question 2

basic neural mechanisms underlying movement include…

Answer 2

• convergence/divergence
• reciprocal innervation/inhibition
• central program pattern generators
• sensory reflexes

Question 3

divergence

Answer 3

allows one neuron to communicate with many other neurons in a network

Question 4

convergence

Answer 4

allows a neuron to receive input from many neurons in a network

Question 5

reciprocal innervation/inhibition

Answer 5

when one set of muscles receives a signal for a reflex action, the antagonistic set of muscles receives a simultaneous signal that inhibits action

Question 6

CPG are…

Answer 6

neuronal networks in which interconnected excitatory and inhibitory neurons produce an oscillating, rhythmic output in the absence of sensory feedback.

Question 7

CPGs play an important part in motor behavior such as..

Answer 7

breathing, swimming, and locomotion

Question 8

What concept is a hard-wired property of neuronal networks and involves both UMN and LMN?

Answer 8

reciprocal innervation

Question 9

describe the two pathways sensory neurons take during the knee-jerk reflex

Answer 9

1 - sensory neurons send signal to spinal cord, from where motor neurons relay the info to quads, causing it to contract and jerk the leg
2 - sensory neurons also synapse with interneurons which send inhibitory signals via other motor neurons to the hamstring causing it to relax

Question 10

A _______- is defined as a neural circuit that can produce self-sustained patterns of repetitive rhythmic outputs to the muscles involved in the rhythmic behavior in the absence of sensory input

Answer 10

CPG

Question 11

The CPG for locomotion is in the ____________

Answer 11

spinal cord

Question 12

locomotor CPG _________ require higher brain centers

Answer 12

does not

Question 13

The CPG for locomotion is in the ___________ part of the ________ spinal cord

Answer 13

ventral, lumbar

Question 14

The spinal CPG for locomotion consists of both…

Answer 14

rhythm (clock) and pattern generating subunits

Question 15

the CPG for locomotion is controlled by neuron groups in ____________

Answer 15

lamina VII (7)

Question 16

___________________ in the ventral grey matter (mostly lamina 7) regulate locomotor rhythms by communicating to each other across the midline to coordinate behavior

Answer 16

bilateral projecting interneurons

Question 17

The activity of the locomotor CPG is modulated via sensory…

Answer 17

feedback and sensory input

Question 18

the activity of the locomotor CPG is modulated via these descending tracts…

Answer 18

corticospinal
rubrospinal
reticulospinal
vestibulospinal

Question 19

CPG receives input from what two pathways?

Answer 19

proprioceptive and exteroceptive

Question 20

____________ feedback determines the magnitude and timing of CPG activity

Answer 20

local

Question 21

____________ feedback regulates intensity and coordinates CPG activity with other motor acts

Answer 21

long loop

Question 22

CPG activity itself can modulate incoming sensory feedback, via __________ of the afferent pathways

Answer 22

presynaptic inhibition

Question 23

___________________ to CPG: return signal in response to rhythmic muscle movement, conveys a continuous measurement of the output

Answer 23

sensory feedback

Question 24

What are the 3 nuclei of the reticular formation

Answer 24

midline (raphe)
medial
lateral

Question 25

midline raphe nuclei of reticular formation is responsible for...

Answer 25

- consciousness and alertness - ascending projections for arousal and attention

Question 26

medial nuclei of reticular formation is responsible for...

Answer 26

intrinsic connections for control of eye movement, swallowing, and brainstem reflexes

Question 27

lateral nuclei of reticular formation is responsible for...

Answer 27

descending projections for control of muscle tone, respiration, and arterial pressure

Question 28

What are the three monoamine projections to the spinal cord

Answer 28

serotonin pathway noradrenaline pathway dopamine pathway

Question 29

______________ neurons of the raphe nuclei are involved in the control of sleep-awake cycle and control circadian rhythm via connection to the suprachiasmatic nucleus

Answer 29

serotoninergic

Question 30

The raphe nuclei are also involved in __________ by inhibiting neurons in the dorsal horn of the SC that are involved in tranmission.

Answer 30

controlling pain

Question 31

subset of serotonergic neurons controls the activity of SC neurons associated with....

Answer 31

locomotor CPG

Question 32

SSRI are used to treat depression and mood disorders AND can cause...

Answer 32

muscle fatigue

Question 33

locus coeruleus (LC) part of RF is a major wakefulness ___________ nucleus, due to ______ prjections to the cerebral cortex, thalamus, tegmental nucleus, and _______ projections to sleep-promoting GABAnergic neurons of the basal forebrain and ventrolateral preoptic area

Answer 33

promoting excitatory inhibitory

Question 34

LC activation _______ alterness

Answer 34

enhances

Question 35

LC involved in control of __________, direct projections to the SC and autonomic nuclei of brainstem

Answer 35

autonomic functions

Question 36

LC activation increases ___________ activity and decreases __________ activity

Answer 36

sympathetic parasympathetic

Question 37

_____________ controls behavioral flexibility, posture and balance, arousal of cortex, attention, memory, and emotions

Answer 37

Locus coeruleus (LC)

Question 38

_________ pathways are projection neurons that synthesize and use dopamine as NT

Answer 38

dopaminergic

Question 39

_______________ control pain response in SC, prime neurons for pain hypersensitivity following injury

Answer 39

descending dopaminergic systems

Question 40

_____ controls the "stepping networks" in the SC

Answer 40

domapine

Question 41

hypothalamo-spinal projections of the dopaminergic system control __________ networks in the brainstem and SC (CPG)

Answer 41

locomotor

Question 42

________ pathways are involved in learning, reward, and motivation

Answer 42

dopaminergic

Question 43

dysfunction of __________ pathways and nuclei are associated with disorders like parkinson's disease, ADHD, addiction, and restless leg syndrome

Answer 43

dopaminergic

Question 44

locomotor function is strongly affected by

Answer 44

neuromodulation

Question 45

What are the 3 most common somatic reflexes discussed?

Answer 45

- stretch (knee-jerk) patellar - withdrawal (flexor) - crossed-extensor

Question 46

What is an involuntary, relatively short-latency, and stereotyped motor response set into motion by an environmental stimulus?

Answer 46

reflex