MT1 Sample Flashcards

1
Q

The action potential and synaptic potential are actually special cases of the membrane potential

A

True

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2
Q

Name 3 properties of ion channels

A

ion selectivity, kinetics (time they stay open, etc) state (active, deactivated, etc.)

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3
Q

The neurotransmitter GABA: A. is inhibitory B. opens Cl- channels C. is excitatory D. is a neuromodulator E. depolarizes post-synaptic targets F. A and B G. C and E

A

a. inhibitory b. allows Cl- ions into cell, K+ out of cell

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4
Q

What kind of activity is measured at the level of a nucleus? A. fMRI B. EMG C. graded potential D. action potential E. none of the above

A

none of the above (EEG)

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5
Q

Name the 5 properties of ion channels

A

ion selectivity (what does it let in?) gating mechanism (how does it open?) kinetics (how long does it open) state (is it available to be opened?) location (where is it?)

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6
Q

Dopamine is a neurotransmitter that is directly excitatory

A

False Dopamine is a neuromodulating neurotransmitter

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7
Q

Membrane potential is a special case of equilibrium potential

A

False Equilibrium potential is a special case of membrane potential

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8
Q

During action potential, _____ rushes into the cell, followed by ____ rushing out

A

Na+ rushes in, then K+ rushes out

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9
Q

If Neuron A fires an action potential after simultaneously receiving an EPSP from Dendrite 1 and Dendrite 4, it is an example of: a. IPSP b. temporal summation c. spatial summation d. local summation e. none

A

c. spatial summation

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10
Q

Dorsal root ganglian cell is located in the spinal cord

A

False. The dorsal root ganglian is a cluster of nerve cell bodies (a ganglion) in the posterior root of a spinal nerve. Their axons are afferents that relay sensory information into the central nervous system. The differ from majority of neurons in that an action potential in a posterior neuron may initiate in the distal axon, bypass the cell body, and continue to propagate along the proximal axon until reaching the synaptic terminal. Bare nerve ending in the distal end, possibly covered by meissner or pacinian corpuscle.

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11
Q

What are the characteristics of a pacinian corpuscle? shallow/deep ? small/large receptive field? high/low frequency? transient/sustained?

A

A pacinian corpuscle (onion skin) is: deep large receptive field high frequency transient //sensitive to vibration and pressure //respond to sudden disturbances // ~250 Hz

//unmylenated end of DRG is wrapped by skin cells like an onion

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12
Q

What are the characteristics of a Meissner’s corpuscle?

A

shallow small receptive field low frequency transient //~10-50 Hz // gripping objects //epidermis with unmylinated end of DRG wrapped around it

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13
Q

There is a higher density of Merkel disks on your finger than your arm

A

true

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14
Q

What are the characteristics of Merkel disk cells?

A

shallow placement

small, spotty field

sustained

two point discrimination

//sensitive to form, edges, texture

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15
Q

What two types of mechanoreceptors are probably involved in reading Braille?

A

merkel disks

meissner’s corpuscles

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16
Q

Where do we FIRST start to get direction selectivity from a single cell?

a. S2
b. S1
c. VPN
d. spinal cord
e. none of the above

A

S1

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17
Q

S1 is located in the precentral gyrus

A

false

S1 is located in the (parietal lobe-somatosensory cortex) postcentral gyrus.

It is the main sensory receptive area for TOUCH

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18
Q

Signals from mechanoreceptors in your left hand end up in your right brain hemisphere

A

true!

signals from mechanoreceptors in your right hand cross over to the left brain hemisphere too

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19
Q

Weigert stain stains for

a. soma
b. axons
c. whole neurons
d. whole glia
e. none of the above

A

Weigert stain stains for AXONS

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20
Q

Generator potentials are analogous to [synaptic] / [action] potentials

A
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21
Q

‘Microslip’ events are best detected by the _______ of touch receptor.

A

meissner’s corpuscle

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22
Q

Recordings of neurons along [oblique] / [vertical] trajectories through visual cortex yield neurons with different directional tuning preferences.

A
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23
Q

Which type of bipolar neuron is depolarized by the neurotransmitter glutamate?

A
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24
Q

Ganglion cells of which type have responses to light that are analogous to Pacinian corpuscle responses to touch?

A
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25
Ocular dominance columns in the left V1 alternate between inputs from the left and right eyes (t/f)
TRUE
26
The pinwheel map contains information for color. (t/f)
FALSE; pinwheel map refers to orientation of stimulus (e.g. orientation of bar)
27
MST neurons show selectivity for what type of stimuli?
(medial superior temporal region) moving stimuli in a certain direction
28
The action potential and synaptic potential are actually special cases of the membrane potential.
true
29
On an otherwise dark field of view, light in the form of a plus sign in the upper-left field of view will excite neurons in the
RIGHT LOWER V1
30
Ganglion cells of which type have responses to light that are analogous to Pacinian corpuscle responses to touch?
pacinian corpuscles have a TRANSIENT response... just as MAGNOCELLULAR ganglion cells in the visual system
31
Which type of bipolar neuron is depolarized by the neurotransmimer glutamate?
OFF bipolar cell
32
(circle the appropriate word) Recordings of neurons along [oblique] / [vertical] trajectories through visual cortex yield neurons with different directional tuning preferences.
OBLIQUE neurons in a single cortical column (vertical) have the SAME directional tuning preferences
33
'Microslip' events are best detected by the _______ of touch receptor
meissner corpuscle
34
Generator potentials are analogous to [synaptic] / [action] potentials.
SYNAPTIC
35
The 'Pinocchio Effect' involves a resolutioon of contradictory information supplied by which two sensory systems of the brain?
proprioceptive somatosensory
36
Which area of parietal cortex is known to integrate both tactile sensation and visual information?
area VIP (ventral intraparietal) [monkey experiment with fixed gaze, touching monkey, then presenting visual stimuli in same field; same firing pattern in single cell recording; integration of somatosensory and visual "personal space"
37
As visual information moves from V1 to later processing stages along the ‘what’ pathway, the features being processed become increasingly specific. (T/F)
FALSE as you move from V1 you get increasing generalization across stimulus features (increasingly abstract) due to convergence of different types of information. start to lose retinotopy, receptive field sizes increase, start to respond to shapes, etc.
38
Ocular dominance columns were found by staining for what enzyme?
cytochrome oxidase. it is needed to produce ATP
39
Where does integration first occur between the proprioceptive and somatosensory systems?
S1 (think pinnochio effect)
40
There are more neurons in V1 dedicated to the ______ of gaze. This phenomenon is called ______ expansion.
(center) ; foveal expansion
41
In which layer of the visual cortex is sustained and transient information first integrated?
layer 4
42
Magnocellular information comes into layer \_\_\_\_\_\_, and magnocellular neurons are \_\_\_\_\_\_\_adapting
layer 4; magnocellular is transient; rapidly adapting
43
Left LGN has information coming from which eye?
BOTH eyes
44
Left LGN has information coming from which field of view?
RIGHT field of view
45
An object in your right visual field ends up where on your retina?
left side of retina; both eyes
46
What is the ratio of number of cones in fovea to cones in periphery in these humans, primates, rats
90: 1 60: 1 6: 1
47
In the knee jerk reflex, the motor neuron innervating the hamstring is __________ by an interneuron. This prevents what?
inhibited; this prevents your lower leg kicking back (prevents the hamstring from contracting and stretching the quadriceps muscle, which would activate the knee jerk reflex over and over again in a continual loop.)
48
In the proprioceptive system, a muscle’s dorsal root ganglion cell (also known as the \_\_\_\_\_\_) wraps itself around the _______ portion of the ______ muscle fiber
muscle spindle afferent; non-contractile; intrafusal muscle fiber
49
The muscle spindle afferent fires action potentials when the muscle is (contracted/elongated)?
elongated when muscle is elongated, the contractile portions contract, stretching the muscle spindle afferent, causing generator potentials, and then action potentials.
50
The response of a muscle spindle afferent is (sustained/transient)?
transient there’s a motor fiber that synapses on contractile portion, causing them to reset to the original state after elongation, which resets the non-contractile portion, making it ready for the next elongation
51
The golgi tendon organ carries (sustained/transient) information
SUSTAINED
52
Golgi tendon organ registers tendon \_\_\_\_\_\_\_, which happens when muscles \_\_\_\_\_\_\_\_.
stretch, contract
53
Deflecting stereocilia of hair cells away from kinocilium produces (excitation/ inhibition)? This information is (sustained/transient).
inhibition transient
54
Due to the orientation of hair cells in semicircular canals on the left and right side of the head, if you move your head to the left, hair cells on which side experience **excitation**?
LEFT (because the fluid moves to the right)
55
The otolith organ provides (sustained/ transient) information about the orientation of the head with respect to gravity, and is analogous to the ______ of the visual system.
otolith = sustained ... same as... parvocellular (vision) merkel (somato) golgi tendon (motor)
56
Golgi tendon organ detects ___ stimuli:
sustained
57
When you flex your biceps, the intrafusal muscle fibers are the ones moving your arm
no, EXTRAFUSAL move the arm, intrafusal detect the state
58
1a sensory fibers synapse on A.golgi tendon organs B.extrafusal muscle fiber C.merkel disks D.pacinian corpuscle E.none of the above
E.none of the above ## Footnote *intrafusal muscle fiber*
59
**Gamma motor fibers** synapses on what specific portion within a muscle spindle?
contracile portion of intrafusal muscle fiber
60
The cupula is located in what structure? A.utricle B.saccule C.muscle spindle D.semicircular canal E.none of the above
*semicircular canal*
61
Deflection *towards* the kinocillium does what to the hair cell?
excites the hair cell
62
If you turn your head to the **left**, the **cupula** in your **right** **semicircular canal** shows what kind of activity?
**inhibited** (steriocilia away from kinocilia) | | | | | | | | | | |
63
What structure gives **sustained** **vertical** movement information?
sacule
64
What primary cortex does *vestibular* information end up in?
S1
65
Light *excites* photoreceptors
false; light ON hyperpolarizes photoreceptors, resulting in LESS glutamate being released
66
Which is hyperpolarized by glutamate?
bipolar ON (light ON = less glutamate released less glutamate released = depolarized depolarized = firing firing -\> light ON = bipolar ON)
67
What type(s) of cells fire action potentials? A.retinal ganglion cells B.dorsal root ganglion cells C.bipolar cells D.photoreceptors E.none of these
ganglion cells: retinal ganglion dorsal root ganglion
68
What type(s) of cells signal sustained stimuli A.parvocellular ganglion cells B.magnocellular ganglion cells C.bipolar cells D.photoreceptors E.none of these
**parvocellular bipolar cells photoreceptors** *also...* sacule otoliths merkel disks golgi tendon
69
Information received by the left eye goes to both V1 hemispheres
TRUE
70
Information received by the left LGN goes to both V1 hemispheres
FALSE
71
rapidly adapting deep placement very large field high frequency vibration
Pacinian Corpuscle
72
rapidly adapting shallow placement 3-5 mm response field (small) low frequency vibration
Meissner Corpuscle (slip/grip control)
73
slowly adapting shallow placement small, spotty field form, texture, edges
Merkel Disks
74
In which structure do signals from the DRG (dorsal root ganglion) transfer to the other hemisphere of the brain?
medulla
75
Cortical Layers of Somatosensory slowly (sustained) adapting information comes into layer \_\_. rapid comes into layer _ and projects up to layer \_, where information about change and constancy is first integrated. then transmitted down to cortical layers and transmitted out for different functions
slow into layer 2 rapid into layer 4 integrated in layer 2 transmitted down and out
76
where does RA/SA (transient/sustained) information FIRST integrate in the somatosensory cortex?
in layer 2 sustained into 2, transient into 4, integrated in 2
77
What happens to the nature of somatosensory information as it moves from S1 to S2
the response fields generalize across digits, but remain directional selectivity
78
describe the knee jerk reflex, from the DRG onward
When the DRG is stimulated, it stimulates motor neuron that triggers quad, as well as a local interneuron that inhibits the hamstring from kicking back
79
describe the parts of the somatosensory cortex
80
What kind of information is carried by the muscle spindle afferent?
carry information about -transient- elongation of the muscle. There is a particlar type of motor fiber that synapses on the contractile regions which cause them to reset to their original state, which can then reset or restretch the noncontracile portion. This allows the muscle spindle afferent to trasmit only transient information rather than be stretched the entire time the muscle is elongated
81
how does the intrafusal muscle fiber function?
2 parts: contracile and noncontractile portion DRG/muscle spindle afferent wraps around the the non contracile portion, of intrafusal mf is the muscle spindle afferent. when the contraclie region contracted, the noncontracile portion is stretched which causes deformation of the unmylenated portion of the DRG and causes generator and action potentials depending on the degree of elongation
82
Name 4 functions of proprioception
joint-protecting reflexes (e.g., knee-jerk) adjustment of musclec ontraction/recruitment kinesthesia: detection of body positio nand movement coordination of motor commands
83
Name 3 functions of the vestibular system
Postural reflexes Gaze adjustment Assessment of self-motion
84
hair cells ____ at rest
tonically release neurotransmitter
85
if you move your head to the right… which semicircular canal will be inhibited?
LEFT will be inhibited
86
oriented vertically gives horizontal head change info
utricle
87
sustained information vestibular system
otoliths! (utricle and saccule)
88
HCs oriented horizontally, vertical information
saccule
89
how do the otolith organs work?
otoliths pushing down on gelatin causing excitation of hair cells the constancy of the excitation results in sustained information about the head’s orientation relative to gravity
90
describe the vestibular pathway
91
who came up with the idea of cortical columns?
Vernon Mountcastle
92
primary visual cortex is also known as
v1 / striate cortex/ area 17
93
all neurons in a cortical column share the same ....
response field, sensitive to input on the same area of the retina
94
neurons in adjacent cortical columns share...
similar or co-located response field different orientations
95
describe OPTOGENETICS
new technique taking genetic manipulations (viral vector) to create neurons that have ion channels that can be controlled with laser stimuluation (Na+ to , Cl- in to silence them)
96
Calcium imaging
measures the flow of calcium into neurons (indicator of flow of Ca that is required to fire an AP) tells you which neurons are active
97
in which direction are photoreceptors oriented in the retina?
oriented toward the back of the eye
98
photoreceptors at rest ....
... tonically release glutamate
99
light does what to photoreceptors
hyperpolarizes them... they release LESS glutamate
100
hyperpolarization of photoreceptors to glutamate is an example of
disinhibition
101
what is the order of connectivity in the visual system?
photoreceptor \> bipolar cell \> ganglion cell \> LGN \> V1
102
where do we see the first action potential in the visual system?
in the retinal ganglion cell
103
when a light is ON... what happens to ON bipolar cells?
photoreceptors release LESS glutamate... ON BIPOLAR CELLS.... ... hyperpolarized by glutamate ....receiving less of it ... is less hyperpolarized ... INCREASES voltage
104
when a light is ON... what happens to OFF bipolar cells?
when light is ON... OFF bipolar cells... ...receive less glutamate ... are depolarized by glutamate ... voltage decreases
105
When light is OFF, what happens to the photoreceptors?
when light is OFF ... Photoreceptors are NOT hyperpolarized... ... release MORE glutamate
106
when light is OFF what about ON bipolar cells
decrease voltage when light is OFF ... receive MORE glutamate ... are hyperpolarized by glutamate ... become more hyperpolarized ... so decrease voltage
107
When light is OFF what happens to OFF bipolar cells
OFF bipolar cells are depolarized by glutamate when light is OFF receive MORE glutamate from photoreceptors are depolarized by glutamate so voltage INCREASES
108
what are the relative distribution of : parvocelluar magnocellular koniocelluar ... cells in the brain?
80% parvo (sustained) 10% magnocellular (transient) 10 % koniocellular (color)
109
what does a PARVOCELLULAR-X-ON look like during an ON stimulus