Neuroscience 3 Flashcards
(202 cards)
1
Q
What are the layers of the eyeball from outside in?
A
Sclera, choroid, retina, vitreous body
2
Q
What is the pathway for light waves as they enter the eye?
A
Cornea, Aqueous humor, Lens, Vitreous humor
3
Q
The opthalmic artery enters the bony orbit via the optic canal and gives off the:
A
central artery of the retina
4
Q
Occlusion of the opthalmic artery may result in:
A
ipsilateral blindness
5
Q
Where is the nucleus of CN III?
A
Tegmentum of the midbrain
6
Q
CN III innervates the motor fibers of the:
A
Superior rectus Medial rectus Inferior rectus Inferior oblique Levator palpebrae
7
Q
CN III innervated the PS fibers of the:
A
Ciliary muscle
Sphincter pupillae muscle
8
Q
What is “down and out” and what nerve is out?
A
External strabismus, CN III is out, and eye is down and out due to unopposed action of superior oblique (4) and lateral rectus (6). This also can cause diplopia
9
Q
What is ptosis? What CN damage is associated with it?
A
Droopy eyelid, CN III or Horner’s syndrome
10
Q
What is mydriasis and what CN damage is associated with it?
A
Dilated pupil, CN III, can also have blurred vision (impaired accommodation)
11
Q
Damage to CN IV can result in:
A
Vertical diplopia, patient can’t look down ie when going down stairs
12
Q
True or False: CN IV and CN VI only have motor input.
A
True
13
Q
What is the onlyCN to emerge on the dorsal surface of the brain stem, with contralateral projection?
A
Trochlear, CN IV
14
Q
What is internal strabismus and what CN damage is associated with it?
A
Eye deviates medially due to unopposed action of medial rectus muscle, damage to CN VI - abducens
15
Q
Nucleus of CN VI is located in:
A
the pons
16
Q
Ophthalmic nerve is also known as:
A
V-1 of trigeminal nerve, CN V
17
Q
Name the branches of the ophthalmic nerve:
A
- Tentorial (meningeal branch)
- Lacrimal
- Frontal
- Nasociliary
18
Q
What is papilledema and what are some conditions that cause it?
A
Swelling of optic disc, associated with tumor, bleeds, impaired CSF reabsorption, increased CSF production, ventricular obstruction
typically bilateral with visual acuity unaffected unless extreme case
19
Q
A relaxed ciliary muscle causes the lens to become __1__ and is used for __2__.
A
- Lens is less convex
2. Far vision focus
20
Q
A contracted ciliary muscle causes the lens to become __1__ and is used for __2__.
A
- Lens more convex
2. Near vision focus
21
Q
Gray matter is composed of:
A
neuronal cell bodies
22
Q
White matter is composed of:
A
axons
23
Q
Where is the limbic lobe in the brain?
A
Directly above the corpus collosum (cingulate gyrus)
24
Q
The precentral gyrus is also known as:
A
primary motor cortex
25
The postcentral gyrus is also known as:
the primary somatosensory cortex
26
Warnicke's areas includes:
the supramarginal gyrus
| the planum temporale
27
The primary visual cortex is on the banks of the:
calcarine sulcus (covers the lingual sulcus and the cuneus)
28
The middle cerebral artery supplies:
```
Primary motor
Primary somatosensory
(for the above **not leg and foot)
Broca's
Wernicke's
Primary Auditory
Frontal lobe
Superolateral portion of temporal lobe
```
29
The anterior cerebral artery supplies:
Primary Motor and Primary somatosensory - leg and foot areas
| Medial surface of cortex
30
The posterior cerebral artery supplies:
Inferior and medial portions of the cerebral cortex
Primary visual cortex
Temporal lobe areas responsible for memory
Thalamus and Midbrain
31
The lenticulostriate arteries supply:
The basal ganglia
| Internal capsule
32
The blood supply of the pons come from:
The basilar artery
33
The base of the pons contains axons of the corticospinal tract and what CN's?
CN VI and VII
34
What is the blood supply of the medulla?
PICA, AICA
35
The CSF flows into the 4th ventricle where it exits the __1__ into the sub-arachnoid space through three holes in the lining of the ventricles and the pia mater: __2__ and __3__.
1. ventricular system
2. foramen of magendie (medial)
3. foramina of Luschka (lateral)
36
Eventually, CSF is reabsorbed into the venous system through:
the arachnoid villi
37
The subcortical gray matter of the thalamus includes:
1. Pulvinar
2. Anterior tubercle
3. Lateral geniculate body (visual from eye to V1)
4. Medial geniculate body (auditory info from Heschel's)
38
The lenticular nucleus (putamen and globus pallidus) and the striatum (putamen and caudate nucleus) make up the gray matter of the:
basal ganglia
39
What are the symptoms of Parkinson's Disease:
1. shuffling gait
2. limb rigidity
3. masked expression
4. difficulty initiating movements
5. pill rolling tremor of hands
40
Where is the lesion implicated in Parkinson's disease found?
Substantia nigra - basal ganglia
41
Uncontrollable hand writhing movements and mental status changes such as dementia siggest what diagnosis?
Huntington's Disease (putamen and caudate nuclei)
42
Wild, flailing movements of the limbs are suggestive of what diagnosis of the basal ganglia?
Hemiballism (subthalamic nucleus)
43
The internal structures of white matter include:
1. corpus callosum
2. fornix
3. anterior commissure
4. posterior commissure
5. optic tract
6. optic chiasm
7. optic nerve
8. corona radiata
9. Internal capsule
10. Crus Cerebri
44
What is this? The funnel in which axonal tracts carry information from the thalamus to the cortex, and from the cortex to the striatum, brain stem (*corticobulbar) and spinal cord (*corticospinal).
Internal Capsule
45
Damage to what part of the internal capsule results in symptoms of sensory loss and paralysis?
Posterior Limb
46
What makes up the lenticulate nucleus?
Putamen, globus pallidus - part of basal ganglia
47
Lenticulostriate arteries and/or the anterior choroidal artery supply the:
posterior limb of the internal capsule
48
What is the cause of retinitis pigmentosa?
Degeneration of rods, then cones due to mutations in rhodopsin gene
49
What are the symptoms of macular degeneration?
Loss of central vision and acuity
50
What is the leading cause of vision loss?
Age-related macular degeneration
51
Blocked, blurred vision is a symptom of?
Diabetic retinopathy
52
What is the treatment for diabetic retinopathy?
Laser surgery etc.
53
The common retinal disorders are:
retinitic pigmentosa
macular degeneration
diabetic retinopathy
54
The visual system is very good at detecting spatial:
contrast
55
ON center cells increase their discharge rate to luminance _____ in the receptive field center
increments
56
____ center cells increase their discharge to luminance decrements in the receptive field center.
Off
57
Receptive fields of ganglion cells have a __1__. They come in 2 types: on-center and off-center ganglion cells.
1. center and antagonistic surround
58
Where does an on-center ganglion cell cell have its excitation?
Center
59
Where does an an off-center ganglion cell have its excitation?
Periphery
60
Bipolar cells have what instead of APs?
Graded potentials
61
Graded depolarization of bipolar cells leads to increase ___1___ release at their synapses and ___2___ of ganglion cells they contact.
1. glutamate
| 2. depolarization
62
On-center bipolar cell __1__ in light (and __2__ in dark)
1. depolarizes
| 2. hyperpolarizes
63
Off-center bipolar cell __1__ in light (and __2__ in dark)
1. hyperpolarizes
| 2. depolarizes
64
Center and surround receptive fields are constructed neurally where?
At the level of the retinal bipolar cells (receiving synaptic input from cones)
65
In hyperpolarization of off-center bipolar cells, what is hyperpolarizing and what NT release is lessening?
cones are hyperpolarizing (leads to BC hyperpolarizing), glutamate release goes down
66
Cone hyperpolarization in on-center bipolar cells results in:
BC depolarization (also glutamate DECREASE)
67
What determines the the on/off center properties of bipolar cells?
Glutamate receptors
68
On-center bipolar cells have what kind of glutamate receptors?
Metabotropic
69
Off-center bipolar cells have what kind of glutamate receptors?
Ionotropic (AMPA, kainate)
70
What cells connect bipolar cells to cone cells?
Horizontal cells
71
Horizontal cells have what kind of potentials?
Graded
72
Horizontal cells to what for bipolar cells?
Provide *lateral inhibition/antagonism* in that they tend to antagonize the bipolar cells' response to light
73
Cones synapse on __1__ to form receptive field centers, and on horizontal cells to form receptive field __2__.
1. bipolar cells
| 2. surrounds
74
What is the basis for trichromatic color vision?
short (blue), medium (green) and long (red) cone cells
75
What are cone opsins?
GPCR superfamily where the cis-11- retinal chromophore sits
76
No green detection comes from:
no expression of M opsin, deuteranopia
77
No red detection comes from:
no expression of L opsin, protanopia
78
What kinds of ganglion cells carry color information?
Parvocellular cells
79
What kind of cells are luminance encoding?
Magnocellualr cells
80
Blue on/yellow off cells are:
koniocellular cells
81
The class of "intrinsically photosensitive retinal ganglion cells" play important roles in non-image forming vision such as:
1. Inform ambient light intensity
2. Synchronize circadian rhythms
3. control the pupil response
82
What is declarative memory?
Remembered events, images, cognitive skills that can be summoned at will, and is *available to consciousness*
83
Patient HM suffered what complication of epilepsy surgery?
Anterograde amnesia
84
Autopsy of RB revealed what area of the brain that contributed to his amnesia for declarative memory?
CA1 area of the hippocampus
85
Spatial learning and memory (in rodents) depends on:
the hippocampus
86
What are the brain areas involved in declarative memory?
Hippocampus and its subcortical connections to the mammillary bodies and dorsal thalamus
87
Short-term storage of declarative memory is __1__ while long-term storage of declarative memory is thought to take place in __2__.
1. Hippocampus and related structures
| 2. Wernicke's, temporal cortex...other cortical sites
88
The physical embodiment of long-term memory is the:
Engram
89
What determines the engram?
Long term changes in efficacy of synaptic transmission
90
What is the theory behind long-term potentiation?
Brain changes that aid in consolidation of declarative memory.
91
What is LTP?
long lasting increase in synaptic strength that provides an attractive neural mechanism for certain learning and memory
92
Where is LTP observed?
Cerebral cortex, hippocampus, cerebellar cortex
93
NMDA receptor activation is required for _____ of LTP.
Induction
94
_____ receptors are required for the expression of LTP (after induction)`
AMPA
95
What kinds of synapses have been studied w/r/t their expression of LTP?
Schaffer Collateral-ca1 synapses in the hippocampus
96
Why are Ca1 pyramidal neurons given to LTP?
They show 1. specificity and 2. associativity. LTP requires strong activity in both presynaptic and postsynaptic neurons
97
The NMDA receptor channel can only open when:
the depolarization is sufficient - high intensity and high frequency to remove the Mg2+ ion
98
What ion is most directly responsible for LTP in the short term?
Ca, which travels through the NMDA receptor and activates AMPA receptor insertion in the postsynaptic membrane
99
What is most directly responsible for LTP in the long-term?
Changes in gene expression and synthesis of new proteins associated with synaptic growth
100
What is LTD?
Long-term depression, a long-lasting decrease in synaptic strength
101
LTD has what effect on AMPA receptors?
Internalization of them from the postsynaptic membrane (opposite of LTP)
102
Where is LTD seen?
Same areas as LTP, Schaffer collateral-CA1 synapses in the hippocampus
103
In LTD, what kinds of Ca2+ changes occur?
Small and slow rises of Ca2+ intracellularly, which correspond to activation of phosphatases instead of kinases.
104
A tumor that produces profound personality changes might involve what gyrus?
Middle frontal gyrus
105
The supramarginal gyrus is directly above what in the brain?
Wernicke's area
106
The superior temporal gyrus is associated with what sensory modality?
Auditory
107
Squirming and fidgeting, but still having control over things like touching a hand to a nose on command indicates a lesion of:
Basal ganglia
108
What cranial nerve runs close to Wernicke's area and can be implicated in a lesion?
Trigeminal, CN V
109
A lesion in the right posterior cerebral artery can result in what visual problem?
left homonymous hemianopia
110
The ventroposterolateral nucleus receives:
axons whose cell bodies are in the gracile and cuneate nuclei on the opposite side
111
The 3rd ventricle is associated with what part of the brain?
Diencephalon
112
What is a synaptic active zone?
Site were special vesicles are docked.
113
What is a PSD, postsynaptic density?
Lots of electrons at postsynaptic cell, many receptors
114
An AP in the motor neuron produces a depolarization of the muscle cell called:
an endplate potential, EPP
115
What is a MEPP made of?
discrete packet of ACh, many packets of ACh make an EPP
116
NT release significantly depends on:
Rise in intracellular Ca channels from opening of voltage-gated channels
117
Blocking voltage-gated Ca channels, for example with certain toxins, eliminates the postsynaptic response because:
no NT is released
118
What is Lambert-Eaton myasthenic syndrome?
Skeletal muscle weakness and fatigue, happens to cancer patients.
119
What is the cause of Lambert-Eaton syndrome?
Reduction in ACh release resulting from a loss of voltage-gated calcium channels in the presynaptic terminal of motor neurons due to an autoimmune reaction where antibodies bind to calcium channels
120
Small molecule NTs such as amino acids have a clear core or dense core? Where are they synthesized?
Clear core, made in nerve terminal
121
Neuropeptides have a clear core or a dense core? Where are they made?
Dense core, made in cell body and transported to nerve terminal
122
Where is the PSD located?
Target zone
123
A form of short-term synaptic plasticity known as facilitation results from:
prolonged elevation of presynaptic Ca
124
Facilitation is also known as:
paired pulse facilitation
125
Why can Ca build up in the synaptic terminal?
Because it takes longer to clear Ca from the target cell than to invite it in.
126
Synaptic facilitation is a __1__ in synaptic strength that occurs when two or more __2__ invade the presynaptic terminal within a few ms of each other. Because of facilitation, the second EPSP is __3__ than the first. It results from prolonged elevation of presynaptic __4__ following synaptic activity.
1. rapid increase
2. APs
3. larger
4. Ca2+
127
Synaptic facilitation means that when APs arrive in close succession, Ca2+ builds up and allows:
more NT release in response to a subsequent AP.
128
Is facilitation observed if two APs are far apart in time?
No
129
What is the major excitatory NT in the CNS? What kinds of receptors does it use?
Glutamate, has both ionotropic and metabotropic receptors
130
How do we get receptor diversity?
Diff arrangements of subunits
131
AMPA receptor channels are selectively activated by __1__ and mediate a __2__ EPSP via the flow of Na and K ions down their electrochemical gradient.
1. AMPA
| 2. fast
132
Which is faster, AMPA receptors or NMDA receptors?
AMPA
133
What ions produce an EPSP in a NMDA receptor?
K, Ca and Na
134
Why do NMDA receptors not typically open?
Because they are blocked by Mg and the membrane must be sufficiently depolarized for the Mg to come off.
135
What kind of receptor channels are AMPA and NMDA?
Ionotropic
136
In most glutamate receptors, an EPSP is made by:
both AMPA and NMDA receptors opening
137
What is CREB?
A transcription factor, influences by intracellular Ca influx at the synaptic terminal
138
What does CREB activity tell us?
Calcium and other 2nd messengers can modify neuronal function by regulating gene transcription.
139
What is the major inhibitory NT in the CNS?
GABA
140
GABA-A receptors mediate:
a fast IPSP via the flow of Cl ions down their ec gradient
141
GABA-B receptors mediate:
a slow signal (bc they are G-protein linked)
142
What is the effect of pentobarbital?
Induces a large IPSP (synaptic GABA channel open for a longer period of time)
143
What is the function of dendrites?
Increases the receptive surface of the neuron
144
How do PSPs differ from APs?
PSPs are small, graded potentials
145
Anterograde transport requires ATP via:
kinesin
146
Retrograde transport requires ATP via:
dynein
147
True or False: Electrical synapses are often bidirectional.
True
148
Where in the CNS are electrical synapses found?
CNS
149
How can a signal can be amplified?
Chemical synapse can amplify a signal - allow for temporal and spatial summation
150
Associate synaptobrevin with:
V-SNARES
151
Associate T-SNARES with:
SNAP-25 and syntaxin
152
V-SNARES and T-SNARES help exocytosis in what kind of synapse?
Chemical
153
Botulinim toxin creates muscle weakness by cleaving:
SNAP-25 or synaptobrevin
154
A muscarinic ACh receptor elicits what effect on cardiac muscle?
Slows heart rate (as opposed to ionotropic Ach receptor) which increases it)
155
If the reversal potential is more + than the threshold, what happens?
excitation results
156
Inhibition occurs if the reversal potential is:
more (-) than the threshold
157
What is decremental conduction?
Before EPSPs can reach the cell soma, a large amount of potential is lost because dendrites are thin and leaky tp electric current
158
A lesion in Meyer's loop produces what VF?
Pie in the sky phenomenon or homonymous quadrantanopia
159
The left VF is dealt with by what hemisphere of the brain?
Right (and vice versa)
160
Where does spatial contrast originate?
Center-surround receptive fields
161
What are the first neurons to receive light input?
The striate cortex
162
What part of the brain is involved in the regulation of circadian rhythms?
hypothalamus
163
What is one main place where optic radiations originate?
LGN, lateral geniculate nucleus
164
What is the central point of the vertical meridian in the retina?
The fovea
165
The LEFT optic tract contributes to what portions of the VF?
Temporal vision of left VF and Nasal vision of right VF
166
The RIGHT optic tract contributes to what portions of the VF?
Temporal vision of the right VF and nasal vision of the left VF.
167
A lesion in the striate cortex looks like?
Macular sparing, homonymous hemianopia
168
Where would a lesion be that produces quandrantanopia?
LGN, VF defect is contralateral to lesion...Meyer's loop lesion applies here
169
The primary visual cortex is located:
around the calcarine sulcus
170
True or False: P, M and K ganglion cells all have center-surround organization.
True
171
The magno pathway has what shaped cells?
Parasol cells
172
The parvo pathway has what shaped cells?
Midget cells
173
The M pathway is known for:
Luminance, contrast detection and motion
174
The P pathway is known for:
Spatial acuity and color
175
How are P and M cells arranged in the LGN?
Layers, with K layers in between
176
True or False: The K pathway is not involved in color processing.
False
177
Color vision is based on cone-:
opponency. We see green as the absence of red, blue as the absence of yellow etc.
178
The K pathway carries what color information?
Blue-yellow
179
Can a single cone cell inform both color and intensity?
No
180
The neocortex has how many layers?
6
181
How does cortical circuitry run in the primary visual cortex?
Vertically, includes inputs from LGN, and resident pyramidal cells, and cells that run information back to the LGN
182
LGN inputs enter V1 and terminate:
in layer 4. Contralateral and ipsilateral effects alternate like stripes (*ocular dominance columns*)
183
What are ocular dominance columns?
Groups of cells that all receive input from one eye. They line up all next to one another like stripes.
184
What is orientation tuning?
Our cortical neurons react more to certain angles that we observe.
185
What is retinotopy?
Retinal mapping
186
What kind of organization is suggested by retinotopy, orientation tuning and ocular dominance?
Columns
187
What is a special characteristic of V1 of the primary visual cortex?
CO, cytochrome oxidase blobs
188
What is contained in CO blobs?
Unoriented color cells
189
Within V1, what are two anatomically segregated pathways?
CO blobs and interblobs (there are more)
190
What is the icecube model?
Functional representation of architecture of V1 proposed by Hubel and Weisel.
191
What is a hypercolumn?
For example, an orientation hypercolumn is a complete set of orientation columns that span all possible preferred angles of orientation
192
Retinotopy is essential for delineating:
visual space/VF
193
Ocular dominance is essential for delineating:
viewpoint
194
Orientation is essential for delineating:
contour extraction
195
What is one suggested reason for why there are more than 30 separate visual cortical areas in the brain, rather than a large V1?
Map shouldn't get too crowded with information organization. Diff cortical areas have different strengths.
196
Semaphorins are mostly:
repellant (non-diffusible)
197
Ephrins have what effect on cells?
Collapse of growth cone
198
__1__ and __2__ guide projections from the retina to the optic tectum.
1. Ephs
2. Ephrins
Axons in the temporal retina are repulsed by ephrin, but axons in the nasal retina are blind to ephrin because they lack the Eph receptor
199
Netrins play a key role in commisural axonal crossing in the:
developing spinal cord
200
In order for axons to not recross the midline, upregulation of what occurs, which reacts to slits in the midline?
Robo
201
The highest level of form vision for primates appears to be:
face recognition
202
Lesions in certain parts of the temporal cortex produce yield prosopagnosia, which is:
the inability to recognize faces
