Module 2: Cognitive Neuroscience Flashcards
(276 cards)
1
Q
Which of the following are necessary for synapse formation? (choose all that apply)
a. formation of the axonal growth cone
b. an appropriate concentration of extracellular sodium
c. the presence of signaling molecules in the extracellular matrix
d. the release of growth factors
A
A,b and d
2
Q
Which of neural processing schemes is most vulnerable to damage?
A
serial
3
Q
The end result of disinhibition on a neural circuit is:
A
Excitation
4
Q
describe the phenomenon of convergence within neural circuits
A
A single neuron can receive synaptic contacts from multiple neurons.
5
Q
What is the main goal of neuroscientists studying the human connectome?
A
Their goal is to map all neural circuits present in the central nervous system.
6
Q
Migrating neurons follow ____ molecules and ____ molecules
A
Signal transduction
Cell adhesion
7
Q
Signaling molecules allow the ______ to identify the correct pathways
A
Axonal growth pathways
8
Q
_______ assist with growth of the axon, formation of the synapse and modulating the number of synaptic connections
A
Growth factors
9
Q
LTP requires ______ presynaptic and postsynaptic neuronal firing (glutamate and its NMDA receptor)
A
Simultaneous/synchronous
10
Q
What is unique about the NMDA receptors?
A
They are dually gated (ligand and voltage gated)
11
Q
LTD requires ______ presynaptic and postsynaptic neuronal firing (glutamate and its NMDA receptor)
A
Asynchronous
12
Q
Single transduction pathways associated with LTP result in _____ influx of calcium ions and activation of protein ______
A
Large
Kinases
13
Q
Single transduction pathways associated with LTD result in a _____ influx of calcium ions and activation of protein ______
A
Small
Phosphatases
14
Q
arrangement of neurons within an assembly that is linear
A
Serial processing scheme
More susceptible to damage
15
Q
Arrangement of neurons within an assembly that contains multiple interconnections
A
Distributed processing scheme
Less susceptible to damage
16
Q
In what kind of excitatory connection does a neuron at lower level of processing excite a neuron at higher level of processing
A
Feedforward excitatory connection
17
Q
In what kind of excitatory connection does a neuron at higher level of processing excite a neuron at lower level of processing
A
Feedback excitatory connection
18
Q
In what kind of excitatory connection do neurons at the same level of processing excite each other
A
Lateral excitation connection
19
Q
The inhibition of inhibition (disinhibition) results in _____.
A
Excitation
20
Q
One neuron sends projection to many neurons
A
Divergence
21
Q
Several neurons send projections to a single neuron
A
Convergence
22
Q
What is an examples of convergence?
A
Rods to bipolar cells in the retina
23
Q
The type of processing that occurs within hierarchical neural circuits where info flows from one area to another in sequence
A
Serial processing
24
Q
The type of processing that occurs within hierarchichal neural circuits where info flows in a side by side manner
A
Parallel processing
25
The type of processing that occurs within hierarchical neural circuits where info flows back and forth
Reciprocal processing
26
Circuits found within all three of the hierarchical circuits are called?
Local circuits
27
What percentage of brain volume is devoted to neurons and glial cells?
80%
28
What percentage of our brain volume is devoted to extracellular space?
15%
29
What percentage of brain volume is devoted to vascular space?
5%
30
Glial cells outnumber neurons by a factor of ____ and account for grater than ____ of the brains volume
10, half
31
What is the function of neuroglia?
Provide structural support
| Carry out many numerous and diverse functions
32
What are the main classes of neuroglia in the CNS?
Oligodendrocytes
Astrocytes
Microglia
33
What are the main neuroglia cell types in the PNS
Schwann cells
| Satellite cells
34
What is the function of Oligodendrocytes
Form myelin sheaths around CNS axons
35
A single oligodendrocyte can send multiple processes to contact and _____ multiple axons
Myelinate
36
What is the largest and most numerous glial cell type?
Astrocytes
37
What is the function of astrocytes during development?
- Produce extracellular matrix proteins, adhesion molecules and chemotactic signals to guide axons to their correct targets
- secrete growth factors for neuronal differentiation, proliferation and survival
38
What are the function of astrocytes after fetal development?
- aid in formation fo the blood brain barrier by using “end feet” to form tight junctions with vascular epithelial cells
- aid in NT removal from nearby synaptic clefts via uptake
- sequester harmful material to protect the CNS
- Intracellular signaling and potentially even intercellular signaling
through the generation of intracellular Ca2+ waves which can travel to
adjacent cells
- Mediate astrogliosis (an increase in the # of astrocytes) and
recruitment in response to neural injury or disease
39
What are the smallest glial cells of the CNS?
Microglia
40
What is the function of microglia during development?
-secrete growth factors during development which aid in formation of fiber tracts, gliogenesis, angiogenesis
41
WHat is the the function of microglia cells after development?
- mediate immune responses within the CNS
| - Become “reactive” and phagocytic during pathological circumstances in the adult CNS
42
What are the phases of microglia immune response?
- Resting phase: microglia are sampling ECF
- reactive phase: microglia activate in response to pathology to change shape, increase in number and engulf harmful debris or compromised cells
43
What is the function of Schwann cells?
- Myelinate peripheral axons in PNS
- mediate regeneration of axons following injury by secreting growth factors, removing debris and providing scaffolding for the growth cone
44
A Schwann cells myelinates _______ of an axon
A single segment
I.e. multiple Schwann cells required to fully myelinate one axon
45
Myelination in the CNS vs the PNS
CNS: oligodendrocytes do the myelination and a single cell can myelinate multiple axons. In axonal injury, cells secrete inhibitory factors. Myelin in CNS is also 30% thinner.
PNS: Schwann cells do the myelination and several cells are required to myelinate single axon. In axonal injury, cells secrete growth factors, remove debris and provide axonal guidance
46
What does the tripartite synapse consist of?
- pre synaptic neuron
- post synaptic neuron
- astrocytes
47
What are the three glialtransmitters?
- ATP
- glutamate
- D-serine
48
What are the functions of glial cells?
- regulate glucose and O2 availability
- release growth factor
- mediate immune response
- promote regeneration
- CNS detoxification
- make saltatory conduction possible via myelination
- aid in synaptic transmission
- participate in gliotransmission
49
How can neural activity be measured directly in the brain?
EEG (electroencephalography) and MEG (magnetoencephalography)
50
How can neural activity be measure indirectly in the brain?
PET (positron emission tomography), fMRI (functional magnetic resonance imaging) or photo acoustic imaging
These methods quantify substrates of metabolic activity as indicators of neural activity
51
Electroencephalography (EEG) measures _______ produced by large populations of neurons through electrodes placed on the scalp
Electrical potentials
52
EEG pattern associated with different behavioral states (sleep, wake, etc.) are _______
Predictable
53
Clinical applications of EEG:
- can be used to measure responses to cognitive tasks
54
An EEG has _____ temporal resolutions and ______ spatial resolution.
Good: less precise
55
Active neurons produce ____ in addition to electrical activity
Magnetic fields
56
MEG records _____ signals produced by synaptic activity
Magnetic
57
How does the temporal and spatial resolution of the MEG compare to the EEG?
Similar temporal resolution but the MEG has better spatial resolution
58
Clinical application of MEG:
Useful in neurosurgery (establishes boarders of tumor) due to reliable spatial resolutions
59
PET scans are measuring _____ which correlated with neural activity
Metabolic changes
60
Why is the PET scan more invasive than MEG or EEG?
A radioactive tracer must be injected
61
Clinical application of PET:
Can be utilized while patient is performing a cognitive task and compared to scan of subject at rest
The change ins regional cerebral blood flow between the two scans indicated brains regions activated during the task
62
The PET detects changes in ________ while a subject is engaged in a cognitive task
cerebral blood flow
Regional cerebral blood flow (rCBF)
63
_______ hemoglobin is more paramagnetic than _______ hemoglobin
Deoxygenated: oxygenated
64
fMRI measures _____ in metabolically active brain regions?
Oxygen levels
65
Increased neural activity = increased cerebral blood flow = ratio of oxygenated to deoxygenated hemoglobin will ______
increase
66
Which has better spatial resolution, PET or fMRI?
FMRI
67
Which is more invasive, PET or fMRI
PET
68
Which has a limited number of scans that can be done per year?
PET due to use of radioactive isotope injections
69
Which has better temporal resolution, PET or fMRI
FMRI
70
specialized structures at the tip of an extending axon that respond to various signaling molecules in order to identify the correct pathways
Axonal growth cones
71
axonal growth, synapse formation, and the number of connections between axons and their targets are influenced by _______
secreted growth factors
72
Once growth cones are converted to specialized presynaptic structures called ________, the formation of neural circuits and networks occurs.
terminal buttons
73
specialized cells for rapid communication through the conduction of nerve
impulses and exchanging information with other neurons.
Neurons
74
Why are microglial cells unique?
They retain the ability to divide
75
Important cellular elements are integrated to comprise neurotypically functioning brain tissue. These integral functional and structural components of the CNS are termed _____
Neural triad
76
The neural triad is composed of:
- neurons
- neuroglial cells
- cerebral vasculature
77
How do neurons contribute to the neurotypically functioning brain?
They provide complex cell to cell interactions among individuals neurons as well as groups of neurons
78
How do neuroglial cells contribute to the neurotypically functioning brain?
They provide structural and functional support
79
How does cerebral vasculature contribute to the neurotypically functioning brain?
supports brain development and function by:
- Contributes to neurogenesis
- Transports O2 and nutrients to and removes waste from the brain
- help form the blood-brain barrier
80
Ca2+ Signaling of Astrocytes Involves:
release of calcium from intracellular stores in response to metabotropic
receptor activation on the astrocyte that initiates a signal transduction pathway (STP) that prompts the release of stored calcium within the astrocyte
81
Slight changes in the concentration of intracellular Ca2+ following activation go metabotropic receptors on the astrocyte can lead to:
Ca2+-dependent
release of neurotransmitter (NT) molecules
- these are considered to be “gliotransmitters”
82
Does Ca2+ signaling within astrocytes display all-or-none features?
No
an increase in intracellular calcium may occur in only a portion of an astrocyte’s process and may or may not spread to other parts of the astrocyte and can transfer to adjacent astrocytes
83
Astrocytes are believed to influence synapse function by:
regulating homeostasis of the interstitial fluid within a synapse via aquaporins and a variety of ion transporters which allow them to regulate pH, as well as maintain appropriate levels of ions and neurotransmitters
84
What is the target of the gliotransmitter ATP?
Glia to glia
85
What is the receptor for the gliotransmitter, ATP?
Metabotropic receptors
86
What is the function/action of the gliotransmitter, ATP/
Decreases glial cell calcium levels
87
What is the target of the gliotransmitter, glutamate?
Neurons and glia
88
What is the receptor of the gliotransmitter, glutamate on neurons?
Ionotropic (AMPAR’s and NMDAR’s)
89
What is the receptor of the gliotransmitter, glutamate on astrocytes/glia?
Metabotropic
90
What is the function/action of the gliotransmitter, glutamate?
- enhances NT release
- enhances EPSPs
- modulates glial calcium levels (increase or decrease)
91
What is the target of the gliotransmitter, D-serine?
Postsynaptic neuron
92
What is the receptor of the gliotransmitter, D-serine?
Ionotropic (NMDAR’s)
93
What is the function/action of the gliotransmitter, D-serine?
Enhances EPSP’s
94
The radioactive tracer injected for a PET scan will emit ______
Gamma rays/photons
95
The ratio of oxygenated to deoxygenated hemoglobin is referred to as the _______ effect
blood oxygenation level-dependent (BOLD)
96
Photoacoustic imaging relies on ______ to produce an image.
light and ultrasound waves
97
Photoacoustic imaging (photoacoustic tomography) can be used for what type of imaging?
Static and functional
98
Photoacoustic imaging (photoacoustic tomography) can be used to measure:
- blood oxygenation saturation
- blood flow
- temperature
99
In Photoacoustic Imaging (photoacoustic tomography), a pulsed laser directs photons into the tissue, which heats the tissues
and creates _______ which are received by a transducer outside the tissue and analyzed by computers
pressure waves (ultrasonic waves)
100
Photoacoustic Imaging (photoacoustic tomography) can be used in conjunction with ____ or _____.
Tracer or probe
101
What is the main benefit of Photoacoustic imaging over fMRI and PET?
safe and non-invasive and can provide real-
time high-contrast images
- safer than PET as it utilizes nonionizing laser illumination
- Image production is faster than MRI and associated costs are
less
102
Photoacoustic imaging produces _____ (high/low) spatial resolution images with greater tissue penetration ability and specificity
high
103
functional neural pathways comprised of neurons within specific nuclei that release one type of signaling molecule that influence numerous other target brain areas.
Single-source divergent networks (SSDNs)
This is the structure of a cognitive network
104
Describe the axons of neurons within single-source divergent networks (SSDNs)
long axons which diverge and send projections to multiple brain regions
105
What are the characteristics of cognitive networks?
- Appear early during embryonic development
- Support all cognitive functions of the brain
- Constantly modulate neural activity and are referred to as “brain state modulatory controls”
- Regulate widespread information flow throughout the brain
- Organized in a hierarchy (local division of labor within the network)
- Exhibit functional stability in the face of local network damage
- Are created and altered by synaptic plasticity processes
- Consist of many long-reaching axonal branches
- Categorized by the neurotransmitter utilized
106
Defects in the networks that utilize biogenic amine neurotransmitters often result in _______.
certain psychiatric disorders
* these circuits are often the targets of pharmacological interventions for psychiatric disorders
107
biogenic amine neurotransmitters include:
- Dopamine
- Norepinephrine/ Epinephrine
- Histamine
- Serotonin
108
What are the 5 Single-source Divergent Networks?
1. Dopamine (DA)
2. Norepinephrine (noradrenaline/adrenaline)(NE/NA)/Epinephrine (Epi)
3. Histamine (His)
4. Serotonin (5-HT)
5. Acetylcholine (ACh)
```
- All 5 networks are interconnected and work cooperatively together to control overall
brain state (consciousness, attention, etc.)
```
109
Network neurons have ______ axons that are highly _______ which synapse on many target cells in various brain regions
unmyelinated, arborized
110
Describe how neural networks work together
within the neural networks are local circuits which contain excitatory and inhibitory synapses, and various processing connections such as: serial, parallel and reciprocal. These connection types are also found between each network, making them highly interconnected.
111
The nuclei that comprise the five single source divergent networks interact with each other in addition to sending projections to various other brain regions including ____ and ____.
the thalamus and cortical regions
112
The 5 modulatory networks are responsible for global brain state activity including:
- consciousness
- sleep and wakefulness
- attention
- emotions
- learning and memory processes
- monitoring of overall physiologic state of the body
113
What are the general features of the 5 modulatory networks?
- Each system utilizes a unique neurotransmitter (small, Ca2+ dependent)
- Neurons contain unmyelinated axons with numerous
branches that synapse on target neurons found throughout the brain
- Neurons contained in single or multiple nuclei located in: brainstem, hypothalamus, & basal forebrain
- All 5 networks are interconnected and work cooperatively
together to control overall brain state (arousal, etc)
114
Where is the tubero-mammillary nucleus located and what neurotransmitter secrete?
Posterior 1/3 of the hypothalamus, histamine
115
Where is the locus coeruleus located and what neurotransmitter secrete?
Rostral pons, norepinephrine
116
Where is the Raphe nucleus located and what neurotransmitter secrete?
Pons and medulla, serotonin
117
Where is the ponto-medullary nucleus located and what neurotransmitter secrete?
Midbrain, acetylcholine
118
Where is the ventral tergmental area located and what neurotransmitter secrete?
Ventral midbrain, dopamine
119
Where is the nucleus accumbens located and what neurotransmitter secrete?
Forebrain, dopamine
120
Where is the nucleus Basalis (of Meynert) located and what neurotransmitter secrete?
Basal forebrain within the anterior perforated substance, acetylcholine
121
Where is the substantia nigra located and what neurotransmitter secrete?
Midbrain, dopamine
122
What are the three network nuclei that secrete dopamine?
Ventral regimental area, nucleus accumbens, substantia nigra
123
What are the two network nuclei that secrete acetylcholine?
Ponto-peduncular nucleus and nucleus basalis
124
The majority of neurons within the nuclei of the five single source divergent networks have axons that are _______.
unmyelinated
125
The release of neurotransmitters (NTs) from the nuclei of the five single source divergent networks occurs through action at _____ synapses from varicosities of the axons.
non-directed
126
What is volume synaptic transmission?
Numerous NT molecules are released from varicosities of the axons and can diffuse freely in various directions therefore, this type of release is known as “omnidirectional”.
127
What are the Postsynaptic physiological effects of Volume Synaptic Transmission:
- Large numbers of cells influenced each time NT is released
- Long duration of modulatory effects
- Non-directed action
128
The pathways involved in producing the state of consciousness are referred to as:
ascending reticular activating system (ARAS)
129
The ARAS (reticular activating system) includes several circuits which originate from the ______ and ascend through the intralaminar thalamic nuclei (ILn) and the thalamic reticular nucleus (TRn) of the thalamus to the cerebral cortex.
brainstem
130
All five of the single source divergent networks communicate via axonal projections with the _______.
thalamic ARAS
131
2 main functional nuclear relay regions of the thalamic ARAS
the intralaminar thalamic nuclei (ILn) and the thalamic reticular nucleus (TRn)
132
The ______, a paired brainstem nuclei within the rostral pons, is the principle noradrenergic nucleus of the brain
locus coeruleus (Lc)
133
Functions of the norepinephrine system include:
* Attention and arousal (including the “fight or flight” response)
* Negative emotion processing
* Regulation of deep sleep (non-REM sleep)
* Support learning and memory
* May aid in cognitive performance
134
The sole source of histamine production in the CNS is the ________ of the hypothalamus
tuberomammilary nucleus (TMn)
135
Are the effects of histamine in the CNS excitatory or inhibitory?
excitatory only
136
Are the effects of norepinephrine in the CNS excitatory or inhibitory?
can be either inhibitory or excitatory depending on the receptor subtype present in the target area
137
Functions of the histamine system include:
• Mediation of arousal and attention
• Modulation of body energy stores (energy homeostasis)
•
138
Targets of the histaminergic neurons include:
the brainstem, spinal cord, hippocampus, thalamus, cerebellum, and cerebrum.
139
Targets of the Norepinepherine/Noradrenaline (NE/NA) System
cerebrum, hippocampus, cerebellum, and the hypothalamus as well as limbic structures such as the amygdala
140
Serotonin (5-hydroxytryptamine: 5-HT) is produced mainly in several groups of neurons known collectively as the _______.
Raphe nuclei.
141
Are the effects of serotonin in the CNS excitatory or inhibitory?
can have inhibitory or excitatory influences on target brain regions.
142
Targets of the Serotonin (5-hydroxytryptamine: 5-HT) system are:
cerebellum, brainstem, spinal cord, thalamus, hypothalamus, and cerebrum.
143
Functions of the serotonin system include:
```
• Mediation of attention & arousal
• Inhibition (suppression) of behavior
• Modulation of negative emotions
• Support learning & memory
•
```
144
The principle nuclei of the Acetylcholine (ACh) System
nucleus basalis of Meynert (NB) and the pontopeduncular nucleus (PPN).
145
Are the effects of acetocholine excitatory or inhibitory?
- excitatory only at the NMJ
| - excitatory or inhibitory in the brain
146
Targets of the Acetylcholine (ACh) System include:
thalamus, hypothalamus, hippocampus, and cerebrum.
147
Functions of the acetylcholine system include:
```
- Mediation of attention &
arousal
- Support learning &
memory
- Control of REM sleep
```
148
axonal projections from the dopamine producing and releasing neurons of the Dopamine (DA) System, target neurons of the ______ of the basal forebrain.
nucleus accumbens (nAc)
149
Functions of the dopamine system include:
```
- Mediates the brain’s
SN “positive reward
network” & motivation VTA
- Modulates positive emotion and mood
- Supports learning and memory
-Mediates attention and arousal
```
150
______ is understood to play a main role in reward-driven, reinforcement, and
motivational behaviors.
Dopamine
151
Drugs such as: cocaine and amphetamine activate the dopaminergic system and produce the psychotropic effects characteristic of opiates by:
blocking re-uptake of dopamine by binding to and inhibiting the dopamine transporter (DAT)
152
Methamphetamine and amphetamine also exert their effects by activating _______ resulting in the release of a large bolus of dopamine into the
synaptic cleft.
Ca2+ dependent release of DA
153
Opiates such as: opium and heroin affect the dopaminergic system through _______.
Disinhibition
- They increase the firing of DA neurons in the ventral trigeminal area (VTA) by inhibiting GABA-ergic inhibitory interneurons that inhibit VTA neurons.
154
Tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis affects the dopaminergic system through ______.
Disinhibition
- it inhibits interneurons that inhibit VTA neurons.
155
How does nicotine activate the dopaminergic system?
Binding of a nicotine
molecule to a nicotinic receptor on an excitatory neuron that releases
glutamate molecules into a synapse with neurons in the VTA, causing them to release dopamine.
156
Regardless of the mechanism, increased activation of the dopamine system leads to the production of ________.
“positive feelings and emotions”
The more often these pathways are stimulated, the stronger the motivational drive to continue to activate them becomes.
157
The ______ play a crucial role in the regulation of the sleep-wake cycle
5 Single-Source Divergent Networks
158
What Single-Source Divergent Networks are active during the awake stage of the sleep-wake cycle?
all five networks are active (NE/NA, His, 5-HT,
| ACh, DA)
159
Non-REM sleep is triggered by the release of
| _______ from astrocytes
adenosine
160
Stages 1-4 of non-REM sleep is characterized by the activity of the _______ and _________.
noradrenergic (NE/NA) neurons in the locus coeruleus and the serotonergic (5-HT) neurons in the Raphe nuclei
161
Stages 1-2 of non-REM sleep is considered _____ sleep.
Light
162
Stage 3 of non-REM sleep is considered _____ sleep.
Moderate-deep
163
Stage 4 of non-REM sleep is considered _____ sleep.
Deep/slow-wave sleep
164
following the four stages of non-REM sleep, an individual will enter _____
sleep
REM
165
REM sleep is characterized by the activity of the _______
cholinergic (ACh) neurons in the pons (PPN)
166
What is responsible for the relative physical paralysis that occurs during REM sleep?
Increased activity of GABAergic neurons in the reticular formation (pons) which send projections to inhibitory neurons that synapse on lower motor neurons in the spinal cord
167
An individual will cycle through an average of ______ periods of REM sleep per sleep-wake cycle
4
168
The importance of REM sleep is supported by what finding during development?
REM sleep comprises a higher percentage of the
| sleep-wake cycle surfing development than observed on average for adults
169
What is REM rebound?
Following sleep deprivation, total number of hours of sleep cannot be made up but REM will made up by devoting an increased percentage of the sleep-wake cycle to REM
170
How does REM deprivation affect performance on cognitive tasks?
Significantly worsens performance.
171
What aspect of memory appears to be affected by REM and why?
Memory consolidation
- Increase in percentage of REM sleep during intense periods of
mental activity
- deficits in memory are observed with REM deprivation
- neural firing patterns are the same during REM as during awake and learning
172
that non-REM sleep is important for:
conservation of energy and is restorative for the mind
- sleep deprived subjects exhibited cognitive impairment but not physical impairment
173
The “Sleep Induction” hypothesis attempts to explain how sleep may play a role in _____.
energy conservation
174
According to the “sleep induction” hypothesis, repeated release of NTs during wakefulness will deplete glial cell glycogen stores. Once these energy store are depleted, the glial cells will release _____, which binds receptors in the cerebral cortex, thalamus and brainstem to promote induction of ______ sleep, which will replenish glycogen stores of the glial cells
Adenosine: non-REM
175
A team of researchers at OHSU led by neuroscientist Dr. Jeff Iliff studies the purpose of sleep. Their research has led to the hypothesis that a principle function of sleep is to ______.
remove metabolic waste from the brain
176
Disruption of the CSF waste removal system in the brain has been implicated in certain neurological diseases that result from the accumulation of metabolic waste such as:
Alzheimer’s disease and its associated amyloid beta plaques
177
a form of lymphatic system, utilized by the central nervous system to remove macroscopic waste
glymphatic system
178
Activity within the glymphatic system is significantly _____ during sleep, while its activity is _____ during wakefulness.
enhanced: suppressed
179
The glymphatic system involves rapid fluid exchange between CSF and interstitial fluid facilitated by ______ wound on the membrane of ______ endfeet, which completely surround the vasculature and form the border of the perivascular space
Aquaporin: astrocytes
180
What are the 3 driving forces behind the glymphatic transport
of CSF?
- The pressure created by constant production of CSF causes it to flow through the ventricular system to the subarachnoid space
- Respiration aids in the movement of CSF
- Smooth muscle cells surrounding pial and penetrating arteries cause
pulsations that drive fluid movement
181
Positive emotions are modulated through the _____ system.
dopamine (DA)
182
The processing of positive emotions requires dopaminergic neurons of the ________ in the brainstem to send projections to the ________ in the basal forebrain, which excites it and causes activity of the amygdala to be _______.
Ventral tegmental area
Nucleus accumbens
Inhibited
183
In the processing of positive emotion, the dopaminergic neurons of the ventral tegmental area (VTA) will send projections to what areas of the cortex?
- medial prefrontal cortex
- anterior and posterior areas of the cingulate gyrus
- insula
184
What is the function of the medial prefrontal cortex in the processing of emotions?
Aids in the processes involved in working memory related to positive emotion
185
What is the function of the anterior and posterior areas of the cingulate gyrus in the processing of emotions?
Focuses attention
186
What is the function of the insula in the processing of emotions?
Is activated in and modulates the processing of both positive and negative emotions
187
The processing of negative emotions requires serotonergic neurons of the ________ and noradrenergic neurons of the _______, along with neurons within the ______ region to send projections to the ________ in the basal forebrain, which excites it and causes activity of the amygdala to be _______.
```
Raphe nuclei (nR)
Locus coeruleus (Lc)
Periaqueductal gray (PAG)
Nucleus accumbens
Suppressed
```
188
In the processing of negative emotions, the Raphe nucleus (nR), locus coeruleus (Lc) and the periaqueductal gray region will send projections to what regions of the cortex?
- orbital prefrontal cortex
- anterior cingulate gyrus
- insula
189
What is the periaqueductal gray region responsible for in the processing of negative emotions?
Processing the pain related to that negative emotion
190
What is the function of the orbital prefrontal cortex (Orb PFC) in the processing of emotions?
It processes working memory related to negative emotions
191
All 5 of the single source divergent networks function in attention, arousal, learning and memory. What is a unique function of the dopamine system?
Control of positive emotion and the brains positive “reward” network
192
All 5 of the single source divergent networks function in attention, arousal, learning and memory. What is a unique function of the acetylcholine system?
Control of REM sleep
193
All 5 of the single source divergent networks function in attention, arousal, learning and memory. What is a unique function of the serotonin (5-HT) system?
- Modulation of negative emotion
- inhibition of behavior
- control of deep sleep (non-REM) alone with NE/NA system
194
All 5 of the single source divergent networks function in attention, arousal, learning and memory. What is a unique function of the histamine system?
- modulation of body energy stores (homeostasis)
| - circadian rhythms
195
All 5 of the single source divergent networks function in attention, arousal, learning and memory. What is a unique function of the norepinephrine/noradrenaline system?
- control of negative emotion (along with serotonin system)
- Control of deep/non-REM sleep along with serotonin system
- aiding in cognitive performance
196
Located within the cortex of the cerebral hemispheres are functional units comprised of groups of neurons that work together to process incoming information. These units are called ______.
cortical columns
197
What is the benefit of cortical columns comprised of large groups of neurons compared to individual neurons?
They are able to perform more complex operations by working together to process information (both sensory and motor)
198
Each cortical column typically contains ___ histologically distinct layers
six
199
Cortical columns can be linked together to form larger groupings called _____ that reach across
the cortex and into subcortical areas, particularly the _____.
Modules
| Thalamus
200
Layers 1-3 of a cortical column are also called _____
Supragranular layers
201
Layers 5-6 of a cortical column are also called _____
Infragranular layer
202
Layer 4 of a cortical column is also called ____
Internal granular layer
203
Layer 1 (molecular layer) of a cortical column is comprised of:
dendrites and
| axonal branches of neurons found within other layers that synapse in this layer
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Layer 2 (external granular layer) of a cortical column is comprised of:
pyramidal cells and interneurons
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Layer 3 (external pyramidal layer) of a cortical column is comprised of:
pyramidal cells
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All supragranular layers send projections to layers of other cortical columns. What kind of connections do these layers make?
- Reciprocal connections with I-III layers
| - Non-reciprocal connections with V-VI layers
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Layer 4 (internal granular layer) divides the cortical column into supragranular and infragranular regions and is comprised of:
Mainly stellate cells
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What layer of the cortical column receives input from the thalamus?
Layer 4
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What is the function of layer 5 in a cortical column?
It receives input from the thalamus and sends input to other layers within the same cortical region
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Layer 5 (internal pyramidal layer) is comprised of:
Large pyramidal cells, interneurons and Betz cells
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Layer 6 (multiform layer) is comprised of:
Fusiform cells, pyramidal cells and interneurons
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Layer 6 of a cortical column does not send projections back to adjacent columns (i.e. it is non-reciprocal), but it does send projections to extracortical areas including:
Thalamus
Striatum
Brainstem
Spinal cord
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The thalamus receives input from all regions of the cerebral cortex as well as subcortical regions including SSDN. Information flow within the cerebral cortex is mediated by the action of the
________ neurons while additional information from the internal and external environment is integrated by the thalamus to _______.
supragranular
| layer IV
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What are the three processes involved in memory?
Encoding
Retention
Retrieval
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Acquisition of information - learning
Encoding
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Storage of information
Retention
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Accessing stored information
Retrieval
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Temporal memory is broken down into three general classes:
- short term memory
- working memory
- long-term memory
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the retention of a limited capacity of information that is limited over
time
Short term memory
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a limited capacity to hold information (seconds to minutes) while using that information to plan
and carry out action - keeping relevant information accessible for short time periods while a task is being completed.
Working memory
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the retention of a potentially unlimited amount of information
consolidated from short-term or working memory, which can be stored for a potentially unlimited amount of time
Long term memory
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Working memory utilizes the distinct functions:
- planning: developing and executing a strategy
- selection and suppression: indentifying relevant components of the task and
focusing attention on those
- task monitoring: keeping relevant information “online” and update info as needed
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Characteristics of working memory?
- operates in real time (seconds to minutes)
- has a limited capacity for information
- involves goal-directed actions
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What part of the prefrontal cortex processes
| perceptual data?
- right lateral prefrontal cortex
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What area of the prefrontal cortex processes symbolic data (language and semantic information)
Left lateral prefrontal cortex
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What part of the prefrontal cortex processes positive emotions and positive emotional memories?
Medial prefrontal cortex
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What area of the prefrontal cortex processes negative emotions and negative emotional memories?
Orbital prefrontal cortex
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Working memory requires the activation of areas of the brainstem utilized by the five SSDNs which send projections to the _____ and the _____ of the thalamus.
- thalamic ARAS (intralaminar nucleus: ILn and the thalamic reticular nucleus: TRn)
- mediodorsal nucleus (MD)
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Once the thalamic nuclei have been activated in working memory, they will communicate with regions of the ______
prefrontal cortex (PFC)
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What is the function of the tectum in the attention network which is necessary for developing working memory?
Control auditory (inferior colliculus) and visual (superior colliculus) responses
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What nuclei of the thalamus act as a relay station for information between the tectum, the 5 SSDNs and the cortex in the attention network?
- Thalamic ARAS (Iln and TRn)
| - Pulvinar
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What is the function of the cingulate gyrus in the attention network?
Helps to maintain a state of alertness
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What is the function of the right lateral prefrontal cortex in the attention network?
Aid in working memory related to perceptual processing
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What is the function of the right superior parietal lobe in the attention network?
Controls shifts in attention, including shifts of attention between different spatial locations
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Long-term memory is separated into two major divisions:
Declarative memory
| Nondeclarative memory
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Long term memory is also referred to as:
Qualitative memory
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knowledge that we have conscious access to and is known as explicit memory due to this access
Declarative memory
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Declarative memory requires deliberate recall of information and is further broken down into subdivisions, including:
- semantic memory
| - episodic memory
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Semantic memory provides what kind of knowledge?
Knowledge about the world - includes facts, information, symbolic or language-based experience, and world knowledge
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Episodic memory provides what kind of knowledge?
Knowledge that we recall about the events of our own lives - includes personal events and experiences as well as emotional memories
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Patient H.M. had severe temporal lobe epilepsy and underwent bilateral medial temporal lobectomy. His seizures ceased and his intelligence and motor abilities remained intact.
What did we learn from him?
- Functioning of the medial temporal lobe (MTL) was necessary for memory
- The processes underlying storage of short-term and long-term memory are different
- Two distinct categories of long-term memory exists: explicit (declarative) and implicit
(nondeclarative)
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loss of information/memories for a period of time prior to the event causing amnesia (long-term memories and memory from the period following the event are often intact)
Retrograde amnesia
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loss of information/ memories for a period following the causal
event (memory prior to the event is often retained)
Anterograde amnesia
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Both divisions of declarative memory, semantic and episodic memory, are mediated by the ____.
Medial temporal lobe (MTL)
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The major structures involved in memory within the MTL are:
- the hippocampus
- the amygdala
- the rhinal cortex
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The medial temporal lobe (MTL) functions in learning and memory to:
- binds and keeps track of all relevant circuits utilized by working memory (kinda like a switchboard)
- direct the consolidation of information into long term storage by maintaining linkage of relevant networks so that they can be activated (recalled) later
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What is the function of the hippocampus in learning and memory within the medial temporal lobe?
Mediates spatial memory
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What is the function of the amygdala in learning and memory within the medial temporal lobe?
- modulates the encoding and storage of hippocampus-dependent memories
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The rhinal cortex is divided into two regions. What are those two regions and what function do they have in learning and memory within the medial temporal lobe?
- Perirhinal cortex: control object recognition
| - entorhinal cortex: plays a role in formation and consolidation of episodic and spatial memories
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What is believed to be the mechanism underlying declarative memory formation?
LTP
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There are two forms of LTP. What are they?
- early long-term potentiation (E-LTP) occurs if neurons are stimulated for a short period and results in synaptic changes that last for several minutes to 3 hours
- late long-term potentiation (L-LTP) occurs is neurons receive prolonged stimulation and results in synaptic changes that last 3-24+ hours
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Do the synaptic changes involved in early long-term potentiation result in new protein synthesis within the neuron?
No, also not morphological changes occur
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Do the synaptic changes involved in late long-term potentiation result in new protein synthesis within the neuron?
Yes, also synaptic morphology changes occur
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the induction of LTP by the stimulation of two sets of synapses that are activated concurrently
Associativity
- Thought to strengthen the connections between relevant information
Example: when the sight and the smell of a rose are presented to an individual
several times, eventually the networks involved in the processing of this “sight” and “smell” information will fire simultaneously (associativity). Once LTP mechanisms have “bound” these networks, the sight or smell of a rose alone will activate the other network
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Phenomenon is which LTP is elicited at one set of synapses on a postsynaptic cell, whereas adjacent synapses that were not activated do not exhibit LTP-like changes
Specificity
- Thought to exclude non-relevant connections
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Memory without recall or awareness
Nondeclarative memory
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Nondeclarative memory can be categorized into 4 subtypes:
- procedural/habit or skill memory
- priming
- classical conditioning
- non-associative
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Is nondeclarative (implicit) memory dependent on the MTL?
No
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change in response to a stimuli or the ability to recognize a stimulus as the result of prior exposure to that stimulus
Priming
- Previous exposure or experience activates specific circuits thereby making it easier to “re-activate” the same circuits
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a phenomenon observed on functional imaging following priming
Activation reduction
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the pairing of a neutral stimulus (called the conditioned stimulus) that is paired with a non-neutral stimulus which produces a response (unconditioned stimulus), following pairing the previously neutral stimulus can now evoke a response similar to that of the unconditioned stimulus
Classical conditioning also known as “Pavlovian conditioning”
Ex: dog salivation with bell and food
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The most primitive form of learning that is found in organisms with basic nervous systems and does not rely on the association of two stimuli to elicit a response.
Non-associative learning
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Non-associative learning includes:
- sensitization
| - habituation
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an increase in response after repeated exposure to novel or harmful stimuli
Sensitization
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A decrease in response after repeated exposure to benign stimuli
Habituation
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Habituation utilizes _____ to suppress NT release
Short term depression (STD)
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Sensitization utilizes _____ to enhance the release of NT
Short term potentiation (STP)
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Non-conscious emotional signals may factor into decision-making before conscious processes do. These processes appear to be mediated by the ______.
ventro-medial prefrontal cortex (VM PFC)
- Appears to be responsible for the storage of personal information about past rewards
and punishments
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What behaviors are seen in individuals with ventro-medial prefrontal cortex (VM PFC) lesions?
- little emotion in social situations
- no empathy towards others
- Perform well on IQ and memory tests
- exhibit poor decision making ability o - intact factual knowledge
- emotional memories are absent
- dissociation of socially appropriate goal-directed (reward) behavior and
willful behavioral action
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What are the nuclei of the ascending reticular activating system (ARAS)?
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Thalamic reticular nucleus (TRn)
Interlaminar nucleus (ILn)
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Magnetoencephalography (MEG) is a functional imaging technique that measures brain activity__________ through the visualization of __________.
Directly, magnetic fields
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When processing positive emotions, activity within the amygdala will be __________.
Suppressed by the activity of the nucleus accumbens (nAc)
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Which of the following functions are mediated (entirely or in part) by the serotonergic (5-HT) system?
- modulation of positive emotion
- non-REM sleep
- REM sleep
- attention
Non REM sleep and attention
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The raphe nuclei contain neurons that produce the neurotransmitter ___________ and located in the___________.
Serotonin, brainstem
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Histamine produces only ________ effects in the brain, and the sole source of histamine-producing neurons in the CNS is the__________.
Excitatory, tuberomammillary nucleus (TMn)
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Memory that involves the learning of facts that can be consciously recalled later is referred to as_________ memory.
Declarative
