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Neurobiology I > Somatosensory System > Flashcards

Somatosensory System Flashcards

1
Q

Sensation

A

Triggering the first sensory neuron in a pathway

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2
Q

Perception

A

Conscious awareness of sensation

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3
Q

6 sensory systems

A 
Vision
Hearing
Olfaction
Taste
Touch 
Pain/temperature
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4
Q

Why is it that touch and pain/temperature aren’t considered to be the same sensory system?

A

They use different neurons

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5
Q

Sensory receptor

A

First neuron involved in sensation

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6
Q

How is our perception of our environment limited by our sensory systems?

A

Above and below a given range, no change in sensation is detected

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7
Q

3 steps of perception:

1) _____ stimulus binds to _____ neuron
2) ____ stimulus is transformed into _____ signal
3) _____ awareness of ____ signal (____)

A 
1) Physical 
Sensory
2) Physical
Electrical
3) Conscious
Electrical
Perception
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8
Q

Vision: stimulus, receptor class, cell

A

Light
Photoreceptor
Rods/cones

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9
Q

Hearing: stimulus, receptor class, cell

A

Sound
Mechanoreceptor
Hair cells

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10
Q

Taste: stimulus, receptor class, cell

A

Chemical
Chemoreceptor
Taste bud

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11
Q

Olfaction: stimulus, receptor class, cell

A

Chemical
Chemoreceptor
Olfactory

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12
Q

Touch: stimulus, receptor class, cell

A

Mechanical
Mechanoreceptor
Dorsal root ganglia and cranial nerves

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13
Q

Pain: stimulus, receptor class, cell

A

Mechanical/chemical
Mechanoreceptor/chemoreceptor
Dorsal root ganglia and cranial nerves

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14
Q

Temperature: stimulus, receptor class, cell

A

Thermal
Thermoreceptor
Dorsal root ganglia and cranial nerves

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15
Q

Stimulus modality measures the ____ of a stimulus, answering what question?

A

Quality

What kind of stimulus?

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16
Q

Stimulus location answers what question?

A

Where is the stimulus originating from?

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17
Q

Stimulus intensity measures the _____ of a stimulus, answering what question?

A

Quantity

How strong is the stimulus?

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18
Q

Stimulus timing answers what question?

A

When did the stimulus start/stop?

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19
Q

The more intense the stimulus, the ____ the frequency of firing.

A

Higher

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20
Q

Adaptation determines whether the sensory receptor conveys ____ or _____ properties of the stimulus.

A

Static

Dynamic

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21
Q

What is the difference between static and dynamic receptor activation?

A

Dynamic- starting and stopping of firing, even in the presence of stimulus
Static- continuous firing as long as stimulus is present

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22
Q

What does the threshold of sensory receptor refer to?

A

How intense stimulus must be before sensory information is perceived

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23
Q

What type of receptors are known to have a particularly low threshold, and which ones are known to have a particularly high threshold?

A

Mechanoreceptors

Pain receptors

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24
Q

2 categories of mechanoreceptors: which responds to external stimuli, and which responds to internal stimuli? Both respond to _____ or _____ of tissue.

A

Tactile (external)
Propioceptors (internal)
Stretching or contracting

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25
Q

What is the difference between the nerve endings of mechanoreceptors vs pain and temperature receptors?

A

Mechanoreceptors have encapuslated endings, whereas pain and temperature receptors have free nerve endings

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26
Q

What type of sensory neurons have the biggest axons and are the fastest in conduction?

A

Proprioception

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27
Q

Proprioceptive neurons are labeled how? How is faster vs slower designated?

A

Roman numeral with lowercase letter

Lower the number and letter, faster the neuron (Ia is faster than Ib, which is faster than IIa)

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28
Q

Touch and pain neurons are labeled how? How is faster vs slower designated?

A

Uppercase letter with Greek letter

Lower the letters, faster the neuron (A alpha is faster than A beta, which is faster than B alpha)

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29
Q

Do dorsal root ganglia and cranial nerves have the same developmental origins? Do either of them develop from the neural tube?

A

No

No

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30
Q

From what region(s) of the body do the cranial nerves receive sensory information? What region(s) of the body do the dorsal root ganglia receive sensory information?

A

Face and neck

Rest of body

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31
Q

What do the cranial nerves develop from?

A

Cranial ectodermal placodes (ectoderm)

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32
Q

What do the dorsal root ganglia develop from?

A

Neural crest

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33
Q

Dorsal root ganglia carry ____ information to the ____ ____.

A

Sensory

Spinal cord

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34
Q

What is the role of growth cones in development?

A

Sense environmental signals and guide axons accordingly

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35
Q

What type of receptors are important for dorsal root ganglia axon guidance?

A

Neurotrophin

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36
Q

Neurons are guided to targets in developing system by _____ made by the targets.

A

Neurotrophins

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37
Q

Is it the targets in the developing system or the neurons themselves that contain the neurotrophin receptors?

A

Neurons

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38
Q

What is the name of the type of receptor with which neurotrophins interact?

A

Trk (“track”)

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39
Q

Can any neurotrophin interact with any Trk receptor, or do neurotrophins show affinity for specific Trk receptors?

A

Neurotrophins show affinity for specific Trk receptors

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40
Q

What is the name of the neurotrophin receptor to which any neurotrophin can bind?

A

p75

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41
Q

Do sensory neurons show equal affinity for all neurotrophins, or does each show affinity for one specific neurotrophin?

A

Show affinity for one specific neurotrophin

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42
Q

In addition to guiding the axon towards its target, what other role do neurotrophins play in the developing nervous system?

A

Favor survival of the guided neuron

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43
Q

What are the 2 types of neurotrophin signals? Which one acts in the short-term, and which acts in the long-term?

A

Local (short-term)

Retrograde (long-term)

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44
Q

The local neurotrophin signal is important for ___ ___ to respond to the ____ ____, enabling the axon to grow to the right place.

A

Growth cone

Guidance signal

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45
Q

The retrograde signal occurs when the neurotrophin binding to neurotrophin receptor triggers ______, and the ____ containing the receptor-ligand complex is transported ______ back to the ____ ____, where it promotes cell _____.

A 
Endocytosis
Endosome
Retrogradely
Cell body
Survival
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46
Q

What would be two effects of knocking out neurotrophins or neurotrophin receptors in a developing system? Would these effects occur in all neurons in the system, or just the ones with affinity to the particular neurotrophin?

A

Axon wouldn’t grow to right place
Neuron could die
Just neurons with affinity to particular neurotrophin

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47
Q

What is the difference in outcome between neurotrophin binding to Trk receptors vs p75 receptors?

A

Trk receptor binding usually triggers positive outcomes for the neuron (guidance, survival), whereas p75 binding could trigger survival or apoptosis

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48
Q

What do the Trk receptors function as once neurotrophin has bound to them? On what side of the plasma membrane does this function take place? How does the function of p75 receptors differ from that of Trk receptors?

A

Trk receptors are kinases
Cytoplasmic side
p75 receptors aren’t kinases

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49
Q

What type of sensory neurons favor neurotrophin BDNF?

A

Merkel disks (tactile)

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50
Q

What type of sensory neurons favor neurotrophin NGF?

A

Nociceptive

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51
Q

What type of sensory neurons favor neurotrophin NT3?

A

Proprioceptive

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52
Q

The sensory cortex in the parietal lobe is (rostral/caudal) to the central sulcus.

A

Caudal (closer to the back of the brain)

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53
Q

Most sensory regions of the brain have a ___ _____ area that directly receives information and an _____ area that processes sensory information and integrates with other sensory information.

A

Primary sensory

Association

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54
Q

Information coming in from the cranial nerves and dorsal root ganglia is divided into ______.

A

Dermatomes

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55
Q

Dorsal root ganglia are located on (one/each) side of the spinal cord and service the (same/opposite) side of the body as where they are located.

A

Each

Same

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56
Q

Each dermatome is specific to a specific _____.

A

Vertebra

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57
Q

What are the 4 sections of the spinal cord, and what does each one service?

A

Cervical (shoulders and arms)
Thoracic (mid body)
Lumbar (legs and hips)
Saccral (back of legs, bottom, genital area)

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58
Q

The dermatome that covers the face and part of the neck is serviced by the _____ nerve, or ____ nerve ____.

A

Trigeminal nerve

Cranial nerve V (5)

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59
Q

All the information from a dermatome comes in through (a single/ multiple) dorsal root ganglia.

A

A single

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60
Q

Each dorsal root ganglion has many types of sensory neurons that have their ___ ____ in the dorsal root ganglion.

A

Cell bodies

61
Q

Information entering dorsal root ganglia comes in through the ____ ____.

A

Dorsal root

62
Q

Touch information enters through the ____ ____ and ascends up to the ____.

A

Dorsal horn

Medulla

63
Q

Pain neurons have their first synapses in the ____ ___ and have ___ ___ neurons that bring the information up to the brain.

A

Dorsal horn

Second order

64
Q

The homunculus shows proportional representation of ____ information in body parts. Which parts of the homunculus are biggest, and what does that say about the amount of space those parts take up in the sensory cortex?

A

Sensory
Mouth, tongue, lips, hands
Those parts take up the most space in the sensory cortex

65
Q

The homunculus (sensory cortex) is pre-determined. What does this mean? Can it be changed at all by sensory input?

A

Develops in the absence of sensory input

Can still be changed by sensory input

66
Q

First experiment that showed that the homunculus can re-map: after stimulating 2 fingers of a primate, what happened to the cortical area of the brain that was associated with the 2 stimulated fingers?

A

Area associated with stimulated fingers increased

67
Q

Second experiment that showed that the homunculus can re-map: after removing a primate’s finger, what happened to the cortical area that had been associated with the removed finger?

A

The areas associated with neighboring fingers took over the cortical area associated with the amputated finger

68
Q

The skin somatosensory receptors have their cell bodies in the ___ ___ ___.

A

Dorsal root ganglia

69
Q

Somatosensory receptors in the skin are divided into what 2 categories?

A

Mechanoreceptors

Free nerve endings

70
Q

Mechanoreceptors: what do the Ruffini receptors measure and are they located in the epidermis or dermis?

A

Skin stretch

Dermis

71
Q

Mechanoreceptors: what do the Merkel receptors measure and are they located in the epidermis or dermis?

A

Light touch, edges, points, and curves

Epidermis

72
Q

Mechanoreceptors: what do the Meissner receptors measure and are they located in the epidermis or dermis?

A

Heavy pressure and skin motion

Dermis

73
Q

Mechanoreceptors: what do the Pacinian receptors measure and are they located in the epidermis or dermis?

A

Vibration

Dermis

74
Q

Are hair follicle receptors considered to be mechanoreceptors or free nerve ending receptors?

A

Mechanoreceptors

75
Q

Free nerve endings: 3 categories, located in epidermis or dermis

A

Pain, temperature, chemoreceptors

Epidermis

76
Q

Threshold of skin mechanoreceptors is measured how and in what unit?

A

How much the skin is moved before perception takes place

Micrometers

77
Q

Rate the skin mechanoreceptors in terms of highest to lowest threshold.

A

Highest: Ruffini
Merkel
Meissner
Pacinian

78
Q

How is slow vs rapid adaptation defined?

A

Slow- signal through duration of stimulus

Rapid- fire at beginning of stimulus, then stop firing

79
Q

What 2 skin mechanoreceptors have slow adaptation?

A

Ruffini

Merkel

80
Q

What 2 skin mechanoreceptors have rapid adaptation?

A

Meissner

Pacinian

81
Q

How is 2-point discrimination measured? Which parts of the body have the best 2-point discrimination?

A

With eyes closed, 2 points poke skin- how close can they be together and still be perceived as separate
Fingers and lips

82
Q

Receptive field

A

Area served by single sensory receptor

83
Q

With receptive field, how is receptor density related to discrimination, like in the 2-point discrimination test?

A

Higher density (more receptors per area), increased discrimination

84
Q

How is receptive field size related to discrimination, like in the 2-point discrimination test?

A

Smaller the receptive field, increased discrimination (only if many receptors in that area)

85
Q

Merkel receptors: relative receptive field size and receptor density, discrimination ability

A

Small receptive field, high receptor density

High discrimination

86
Q

Pacinian receptors: relative receptive field size and receptor density, discrimination ability

A

Large receptive field, low receptor density

Low discrimination

87
Q

Merkel mechanoreceptors: slow or rapid adapting (S or R), small (1) or large (2) receptive field, low or high threshold, label

A

Slow
Small
High
SA1

88
Q

Meisner mechanoreceptors: slow or rapid adapting (S or R), small (1) or large (2) receptive field, low or high threshold, label

A

Rapid
Small
Low
RA1

89
Q

Pacinian mechanoreceptors: slow or rapid adapting (S or R), small (1) or large (2) receptive field, low or high threshold, label

A

Rapid
Large
Low
RA2

90
Q

Ruffini mechanoreceptors: slow or rapid adapting (S or R), small (1) or large (2) receptive field, low or high threshold, label

A

Slow
Large
High
SA2

91
Q

When feeling a row of Braille dots, which skin mechanoreceptor’s response pattern will be the most like that of the stimulation pattern? Which will have a similar response pattern to the stimulation pattern, but not as similar as the first? Which 2 will give the least information? Does receptive field size, threshold, or adaptation rate seem to play the biggest role in determining the ability of a skin mechanoreceptor to respond to touching Braille dots? Are all the skin mechanoreceptors active in this example, or just the one(s) that are best at responding to the given type of stimulus?

A 
Merkel
Meissner
Pacinian and Ruffini
Receptive field size
All skin mechanoreceptors
92
Q

Spatial acuity is related to what? Is it more a property of individual neurons or multiple neurons? Why?

A

Discrimination
Multiple neurons
Depends on number of neurons present and size of receptive fields

93
Q

In the dorsal root ganglia, sensory afferents go into the ___ ___ of the spinal cord.

A

Dorsal horn

94
Q

Mechanosensory pathway from back 1/3 of head and rest of body as well as face: how many neurons and how many synapses required to get information to somatosensory cortex? In what region is the 3rd synapse?

A

3 neurons, 2 synapses

3rd synapse is in somatosensory cortex

95
Q

Mechanosensory pathway from back 1/3 of head and rest of body: first neuron with cell body in ____ ____ ___ ascends (ipsilaterally/ contralaterally) to _____. This neuron is part of the ___ tract if it comes from the lower body and is part of the ____ tract if it comes from the upper body (cervical spine). The first synapse in this pathway is in the ____ or ____ nucleus of the ____, depending on which tract it is part of.

A 
Dorsal root ganglia
Ipsilaterally
Medulla
Gracile
Cuneate
Gracile or cuneate nucleus
Medulla
96
Q

Mechanosensory pathway from back 1/3 of head and rest of body: second neuron with cell body in ____ ascends (ipsilaterally/contralaterally) through the ___ ___ and synapses in the ____. What is the name for the fibers that cross in the medulla?

A 
Medulla
Contralaterally
Medial lemniscus
Thalamus
Internal arcuate fibers
97
Q

Mechanosensory pathway from back 1/3 of head and rest of body: third neruon with cell body in the ___ ____ ___ part of the ____ ascends into the ____ ____.

A

Ventral posterior lateral
Thalamus
Somatosensory cortex

98
Q

Mechanosensory pathway from face: first neuron with cell body in ____ ____ enters (ipsilaterally/contralaterally) via ___ ___ ___. This neuron synapses in the ____.

A

Trigeminal ganglion
Ipsilaterally
Cranial nerve V
Pons

99
Q

Mechanosensory pathway from face: second neuron with cell body in ___ ascends (ipsilaterally/contralaterally) through the ___ ___ and synapses in the ____.

A

Pons
Contralaterally
Medial lemniscus
Thalamus

100
Q

Mechanosensory pathway from face: third neuron with cell body in the ___ ___ ___ part of the ___ ascends into the ____ ____.

A

Ventral posterior medial
Thalamus
Somatosensory cortex

101
Q

Proprioceptors are located on ____ and ___ and give information about position of ____ with respect to the rest of the body.

A

Joints
Muslces
Limbs

102
Q

To what part of the brain is proprioceptive information carried? Is it restricted to one side or shared across both sides of spinal cord as it is carried to this part of the brain?

A

Cerebellum

Shared across both sides of spinal cord

103
Q

Do neurons that carry pain and temperature information conduct at a relatively fast or slow rate?

A

Slow

104
Q

3 types of nociceptors and the type of information they convey

A

Mechanosensitive (physical)
Thermosensitive (thermal)
Polymodal (physical, chemical, and thermal)

105
Q

How do thermoreceptors differ from thermosensitive nociceptors?

A

Thermoreceptors convey temperature information in the non-painful range

106
Q

Do nociceptors and thermoreceptors have same or different pathways?

A

Same

107
Q

Do pain and temperature receptors serve the same or different dermatomes as mechanoreceptors? Do they go up to the somatosensory cortex as the mechanosensory neurons do?

A

Same dermatomes

Yes

108
Q

Pain and temperature neurons communicate with _____ neurons in the somatosensory cortex.

A

Mechanosensory

109
Q

Different neurons receiving information about different sensory pathways enable _____ of sensations.

A

Distinction

110
Q

Thermoreceptors’ increase in magnitude of firing is ____ in its optimum window: below that, ___ firing takes place and above that (in the ____ range), the rate of firing (continues to/doesn’t) increase.

A

Constant
No
Painful
Doesn’t

111
Q

Nociceptors start firing once the stimulus is in the ___ range, but increases ____ until ___ ___ has taken place.

A

Painful
Constantly
Nerve damage

112
Q

First pain is considered to be ____ pain, whereas second pain is considered to be ___ pain. First pain is (short/long)-lasting and second pain is (short/long)-lasting.

A

Sharp
Dull
Short
Long

113
Q

The first pain neurons are designated ____, whereas the second pain neurons are designated ____. Which ones are lightly myelinated, and which ones are unmyelinated? Which ones synapse in more superficial layers of the dorsal horn?

A 
A delta
C
First pain- lightly myelinated
Second pain- unmyelinated
Second pain synapse in more superficial layers of dorsal horn
114
Q

Pain neurons cross to the (ipsilateral/contralateral) side of the dorsal horn and then send their axons through the ___ ___ ___ up to the ____.

A

Contralateral
Anterolateral white matter
Thalamus

115
Q

In the 2 point discrimination test, if 2 points are indeed perceived, are the 2 points detected by the same or by different mechanoreceptors?

A

Different

116
Q

For first pain coming from the body, the second synapse is in the ___ ___ ___ part of the thalamus and the third synapse is in the ____ ___. How does this pathway differ from that of second pain?

A

Ventral posterior lateral
Somatosensory cortex
Second pain can travel through many different pathways to many different brain systems

117
Q

Pain and temperature pathways from back 1/3 of head and rest of body: first order neuron carries information through ___ ___ ___ and synapses in ____ ____.

A

Dorsal root ganglia

Dorsal horn

118
Q

Pain and temperature pathways from back 1/3 of head and rest of body: second order neuron with cell body in ____ ____ crosses to (ipsilateral/contralateral) (dorsal/ventral) side and ascends through ____ ____ ____ tract up to the _____ and synapses in the ____ ____ ____ part of this brain region.

A 
Dorsal horn
Contralateral
Ventral
Anterolateral white matter 
Thalamus
Ventral posterior lateral
119
Q

Pain and temperature pathways from back 1/3 of head and rest of body: third order neuron with cell body in ____ ____ ____ of ____ ascends to and synapses in the ____ ____.

A

Ventral posterior lateral
Thalamus
Somatosensory cortex

120
Q

Since pain/temperature and mechanosensory information travel to the same parts of the brain, do their neurons synapse on the same neurons in those parts of the brain? Why or why not?

A

No

Wouldn’t be able to differentiate pain/temperature from mechanosensory information if neurons were the same

121
Q

Pain and temperature pathways from face: first order neuron comes in through _____ nerve (_____ nerve ___) and (ascends/descends) from ____ to _____, where it synapses.

A 
Trigeminal
Cranial nerve V
Descends
Pons
Medulla
122
Q

Pain and temperature pathways from face: second order neuron with cell body in ____ crosses to (ipsilateral/contralateral) side and ascends through ____ ____ tract to ____ and synapses in the ____ ____ ___ part of this brain region.

A 
Medulla
Contralateral
Trigemino-thalamic tract
Thalamus
Ventral posterior medial
123
Q

Pain and temperature pathways from face: third order neuron with cell body in ____ ___ ___ of ____ ascends to and synapses in ____ _____.

A

Ventral posterior medial
Thalamus
Somatosensory cortex

124
Q

Injury to the spinal cord on one side only would affect touch sensation on the (ipsilateral/contralateral) side below the site of injury. Pain information would be affected on the (ipsilateral/contralateral) side below the site of injury. Why is this the case?

A

Ipsilateral
Contralateral
Pain ascends on the contralateral side, whereas touch ascends on the ipsilateral side

125
Q

Damage to what quadrant of the spinal cord (left/right, dorsal/ventral) would affect pain sensation at and below site of injury on the left side? Why?

A

Right ventral
Information from left side enters through left dorsal horn and crosses to right ventral horn, so information entering site of injury would be coming through right ventral horn

126
Q

Damage to what quadrant of the spinal cord (left/right, dorsal/ventral) would affect touch sensation at and below site of injury on the left side? Why?

A

Left dorsal

Information from left side enters through left dorsal horn and ascends through it to brain

127
Q

Damage to the right ventral posterior lateral of the thalamus would affect pain and touch on what sides of the body? Why?

A

Left for both

Both pain and touch have crossed to contralateral side by the time the thalamus is reached

128
Q

What does “referred” pain in internal organs refer to? What causes this phenomenon? How is this demonstrated in the cases of heartburn and heart attack?

A

Damage to internal organs can be perceived as external pain
Pain neurons that service skin also service internal organs
Heartburn: pain in esophagus is perceived near heart
Heart attack: pain in heart is perceived in left arm

129
Q

The thermosensitive channels are designated how? What causes them to open up and pass ions? Do they detect only temperature, or do they detect other things?

A

TRP
Warming of membrane causes conformational change that opens channel
Detect other things (multimodal)

130
Q

The mechanosensitive channels have how many subunits? What kind of structure is a part of each subunit, and how does it help channel function? What causes them to open up and pass ions?

A

3 (trimer)
Blade: amplify effects of stretch or vibration
Stretching of membrane causes conformational change that opens channel

131
Q

TRPV1 can be on (nociceptive/non-nociceptive/either) receptors. What are 3 things that activate it (2 nociceptive/thermoreceptive, 1 spice)? Which one activates from the intracellular side? Why is spice called “hot?”

A

Either
Heat (nociceptive and non-nociceptive), acid, capsaicin (spice)
Capsaicin activates from intracellular side
Spice is called “hot” because it activates the same receptors responsible for heat

132
Q

How do anagesic “heating” creams affect TRPV1 and thus pain?

A

“Heating” creams decrease expression of TRPV1, leading to decrease in pain

133
Q

Each TRP receptor detects a specific range of ______.

A

Temperature

134
Q

Pain propagation through voltage-gated channels: 6 steps

A

Painful stimulus -> mechanoreceptor -> depolarization -> open VG NaV1.7 -> open VG NaV1.8 -> action potential propagation

135
Q

What voltage-gated Na+ channels do scorpion toxins normally bind to? What does this cause?

A

NAv1.7

Increased Na+ current and perception of pain

136
Q

What about the voltage-gated Na+ channels of grasshopper mice enable the mice to not feel pain from scorpion stings? What type of pain is actually inhibited, first or second?

A

Mutation in NAv1.8 causes channel to be inhibited by scorpion toxin binding and provides analgesia
Second pain

137
Q

A mutation to what voltage-gated Na+ channel causes congenital insensitivity to pain? Is it sensation or perception of pain that is blocked in this condition? Why? What kind of condition would occur with a gain-of-function mutation of this voltage-gated Na+ channel?

A

NAv1.7
Sensation of pain (nociceptive neurons don’t fire)
Person would perceive pain in absence of stimulus

138
Q

NSAIDS: do they target inflammation or pain, examples

A

Inflammation

Aspirin, acetaminophen

139
Q

NSAIDS target what enzyme? What does this enzyme make? What does this product cause in the body and what type of nerve endings does it activate?

A

COX enzymes
Prostaglandins
Inflammation
Free nerve endings (pain)

140
Q

In hyperalgesia, what type of stimuli induce pain? What causes this and what is its purpose?

A

Non-painful
Enhanced sensitivity to stimuli
Protect injury from further damage

141
Q

Allodynia is similar to (hyperalgesia/algesia) and occurs in the _____. What type of neurons have high activity, and what causes this increase in activity?

A

Hyperalgesia
CNS
Dorsal root ganglia
LTP-like changes in 2nd order neuron

142
Q

What is neuropathic pain, and what causes it? What type of neurons are damaged and what is the result?

A

Pain in absence of painful stimulus
Disease
1st or 2nd order neurons are damaged, causing increased signaling

143
Q

Descending control of pain: signals from various ____ regions can ____ pain signals at (many/a few) levels.

A

Brain
Modify
Many

144
Q

Descending control of pain: descending inputs from the locus coeruleus can release _____ onto the (C fiber/ dorsal horn projection neuron) and descending inputs from the Raphe nucleus can release _____ onto interneurons that then release _____ (endogenous opioid) onto the (C fiber/dorsal horn projection neuron). Descending systems can (upregulate/downregulate/either) transfer of information from C fiber to projection neuron.

A 
Norepinephrine
Dorsal horn projection neuron
Serotonin
Enkephalin
C fiber 
Either
145
Q

What is phantom limb pain?

A

Person with amputated limb still “feels” limb and experiences pain

146
Q

How does motor imagery for phantom limb pain work? Is it more or less helpful than other kinds of therapy?

A

Person imagines that limb is still there and can be controlled
Less helpful than other kinds of therapy

147
Q

How does mirror therapy for phantom limb pain work? Is it more or less helpful than motor imagery?

A

Person puts functional limb in front of mirror and “sees” missing limb through mirror image of functional limb
More helpful than motor imagery

148
Q

How does phantom motor execution for phantom limb pain work?

A

Electrodes attached to what’s left of person’s limb pick up signals intended for missing limb- person sees on screen movements of virtual limb

149
Q

How is phantom limb pain evidence of top-down regulation?

A

Person experiences pain in amputated limb even though there is no limb to sense pain

Neurobiology I (18 decks)

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