Lecture 1 (chapter 1 & chapter 3)

Question 1

What is Clinical Neuroscience?

Answer 1

o A description is not an explanation. We need to know the mechanisms behind the phenomena.
o The organization of the brain reveals the architecture of the mind! This means that the structure and function of the brain reveals the how behavioural and mental disorders develop.
o Treatment for disorders targets brain changes.

Question 2

Is a description an explanation?

Answer 2

o “Branch of neuroscience that focuses on the fundamental mechanisms that underlie disorders and diseases of the brain and central nervous system, and on scientifically based approaches to diagnosis and treatment”
o Very different from psychology which describes rather than explains disorders or diseases. You need to understand the biological mechanisms that produce disorders, to be able to manipulate them and treat diseases better than using behavioural interventions.

Question 3

Media & neuroscience

Answer 3

o Does not provide accurate representations of neuroscience. They distort or misinterpret empirical research to make more interesting articles for consumers.

Question 4

Nervous system:
• Two main distinctions of the 
   nervous system:
> located in the...
> transmits information...

• Two main distinctions of the PNS:
•

Answer 4

• Two main distinctions of the nervous
system:
• Peripheral Nervous system (PNS)
• Located outside the skull and the spine
• Transmits information to the CNS by
way of sensory nerves (afferent nerves
– towards the brain)
• Transmits information from the CNS to
the muscles, glands, and internal
organs by way of motor nerves –
efferent nerves– away from the brain)
• Sensory neurons are carried from the
dorsal root ganglion in the spinal cord.
• Motor neurons are carried from the
ventral roots in the spinal cord.
• Includes cranial nerves, spinal nerves
and peripheral nerves.
• Twelve pairs of cranial nerves (within
the brain) and 31 pairs of spinal nerves
(on the spine) which connect the the
PNS to the brain and spinal cord.
• Two main distinctions of the CNS:
• Somatic division
• Includes sensory (info into brain) and
motor (info out of brain) nerves
• Controls skeletal and voluntary
movement (i.e., typing)
• Autonomic division
• Controls glands and muscles of internal
organs, and regulated internal bodily
processes (i.e., breathing & heartbeat)

• Central Nervous System (CNS)
• Located in the skull and spine - consists
of the brain and spinal cord

Question 5

afferent vs efferent nerves

Answer 5

afferent nerves – towards the brain (i.e., sensory neurons)

efferent nerves– away from the brain (motor neurons)

Question 6

Peripheral Nervous system (PNS)

Sensory neurons are carried from the ____ in the spinal cord.

Motor neurons are carried from the ___ in the spinal cord.

Answer 6

• Sensory neurons are carried from the
dorsal root ganglion in the spinal cord.
• Motor neurons are carried from the
ventral roots in the spinal cord.

Question 7

how many cranial nerves are ther in the PNS?

Answer 7

12

Question 8

(4) Anatomical directions

Answer 8

•	Anterior: to the front (also known as 
        rostral in four-legged animals) 
•	Posterior: to the rear or tail (also known 
        as caudal)
•	Dorsal: to the back or top 
•	Ventral: to the belly or bottom

Question 9

(2) Anatomical directions

Answer 9

• Lateral: to the side (away from the midline
of the body) refer to lateral if it is to the
side of the midline, or to the side of
something
• Medial: to the midline (towards the midline)
refer to it as medial if it is closer to the
midline

Question 10

what is Ipsilateral and Contralateral?

Answer 10

• Ipsilateral: Same side of the body

* Contralateral: Opposite side of the body

Question 11

(3) brain cuts

Answer 11

o Horizontal plane (parallel to the top of
the brain)
o Sagittal plane (parallel to the midline of
the brain)
o Coronal plane (parallel to the front of
the brain)

Question 12

If someone has a stroke in motor context of the right hemisphere what happens?

Answer 12

Consequences of a stroke always occur in the contralateral side (i.e., if stroke in the right hemisphere it effects the left side of the body & vise versa. Why? Due to hemisphere lateralization!). Do not use the words right or left in academic journals to describe the area of the body effected!

Question 13

Hemispheres are….

Answer 13

• Hemispheres are asymmetrical and vary in size (e.g., left frontal is larger in size than right frontal)
• Hemispheres have been described as specialized in function
o Left hemisphere: Language-related functions, logical thinking, and writing
o Right hemisphere: Visuospatial, musical, and artistic abilities

Question 14

what are commissures?

Answer 14

Commissures (group of fibers that act as channels that connect both hemispheres; the biggest on is the corpus callosum) act as a conduit through which the right and left hemispheres exchange information and function interdependently.

Question 15

If you cut the corpus callosum, separate the left and right hemisphere, this would cause?

Answer 15

Stop communication between the hemispheres, referred to as split brain patients, it can be done surgically to stop or lessen severity of sezuires. They cannot learn new behaviours which requires interdependent movement of both hands (i.e. play piano), cannot gain access to information about object names stored in the left hemisphere if the object is held in their left hand (activates right hemisphere), may have trouble using left hand to execute verbal tasks, patients are unable to name odours presented to the right nostril, though the left hand can point out the source.
• Note on neuroplasticity, more prominent in young children, lessens as we age and brain becomes less resilient.

Question 16

Gyri and Sulci (folds & grooves in the brain)

Answer 16

• The size and shape of the skull cause the cortical structure of the brain to fold inward
o Bumps are called gyri (peaks)
o Grooves are called (crevasse)
§ Sulci (smaller groove)
§ Fissure (major groove)
§ Horizontal & central fissures are used to divide the brain into lobes. Anything which falls below the horizontal fissure is the temporal lobe & above is the frontal lobe. Anything which falls behind the central fissure and above the horizontal is the parietal lobe & below is the occipital lobe.

Question 17

(4) Lobes and their location

Answer 17

• Frontal: Most anterior (at the very front of
the brain)
• Parietal: Posterior and dorsal to the frontal
lobe (behind & above)
• Temporal: Located on the lateral surface (on
the side)
• Occipital lobes: Most posterior (at the back
of the brain)
• Although each lobe is associated with
primary functions, the four lobes are highly
interconnected

Question 18

What are Gray and white matter

Answer 18

• The cortex consists mainly of cell bodies, it has a grayish appearance and is commonly referred to as “gray matter”
• Neurons projections (axons) are often covered in myelin and are referred to as “white matter”
• Random side fact - The total surface area of the cortex is roughly equivalent to 2.5 square feet of flat surface. Why does the brain have the grooves (sulci) because the shape of the skull cause the brain to fold in on itself. The skull is smaller to allow for women to give birth.
• White matter – myeline sheath on axons appear white (lipid which insulates axons and improves speed of neurotransmitter)
• Gray matter - cell bodies appear gray in colour

Question 19

Hemispheric differences

Answer 19

• Derived from individuals with brain damage
o Damage to the left frontal lobe (Broca’s area) or left temporal lobe (Wernicke’s area) can result in difficulties with language production and comprehension
o Damage to the right hemisphere: Spatial reasoning difficulties, such as judging line orientation and interpreting facial expressions
o Brocas’ area: knows what they want to say but have difficulty finding correct word, poor grammar, poor reading skills, difficulty pronouncing words (left hemisphere damage; located lateral cortical in the prefrontal left hemisphere).
o Wernick area: can talk but not aware of all the mistakes yours making, incoherent speech, find it hard to understand speech (due to damage in right hemisphere; located

• Language and reading are largely, although not exclusively, left hemisphere dominant in both males and females
• In congenitally blind individuals, a reduction is found in left hemisphere lateralization when performing language-related tasks (plasticity! Is this because reading becomes a touch rather than visual task?)
• In terms of hemispheric control of the body, the left hemisphere generally controls the right side of the body and the right hemisphere controls the left side of the body (i.e., contralateral control)
• What happens if stroke impacts left hemisphere? Affects the right side of the brain. Recovering from the damage is more likely the younger they are due to them having higher neuroplasticity (will develop skills in undamaged areas; could swap to the other hemisphere), and their skills are more diffused, brain structures are not fully developed and can be modified.

Question 20

Frontal lobe functions and clinical disorders associated with it

Answer 20

Frontal lobe (executive control)
•	Strategic planning
•	Impulse control
•	Flexibility of thought and action
•	Broca’s area: Frontal lobe of the left hemisphere.

*Several clinical disorders are characterized by executive function deficits, including
attention deficit hyperactivity disorder (ADHD), Alzheimer’s disease, schizophrenia,
obsessive compulsive disorders

Question 21

Parietal lobe functions and clinical disorders associated with it

Answer 21

Parietal Lobe
• Processes and integrates information concerning the body’s position in space and sensory information from the skin, such as touch, pressure, and pain
• Damage to the right parietal lobe can result in:
o Contralateral neglect (deficit in attention to one side of the visual field; when draw a clock would only draw half of the clock or put all numbers to one side of the clock).
o Anosognosia (lack or self-awareness)
o Disorders of tactile function, spatial ability, and drawing are also associated with damage to the parietal lobe

Question 22

Temporal lobe functions and clinical disorders associated with it

Answer 22

Temporal lobe
• Primary auditory cortex located in the temporal lobe plays a critical role in the processing of sounds
• The left hemisphere of the temporal lobe contains a region known as Wernicke’s area that is critical to understanding spoken language

Question 23

Occipital lobe functions and clinical disorders associated with it

Answer 23

Occipital lobe
• Analysis of visual information
• Damage results in visual perception disturbances (agnosias)
o Apperceptive agnosia: Failing to recognize a visual stimulus due to a perceptual impairment
o Associative agnosia: Failing to recognize objects because of faulty memory

Question 24

Limbic system

Answer 24

• Sits below the (4) lobes
• Subcortical group of structures
• The limbic system is involved in motivated behaviors, such as sexual behavior, eating, and aggressive behavior, as well as learning, memory, and recognition and expression of emotion.

Amygdala
• Plays an important role in the development of anxiety disorders and drug-seeking behaviors (in the limbic structure)

Basal ganglia
• Subcortical cell bodies that play a critical role in movement (motor control)
• Outgoing motor response to incoming sensory information
• Structure important in Parkinson’s disease

Question 25

Ventricles of the brain function

Answer 25

Ventricles of the brain
•	Set of communicating cavities responsible for the production, transport and removal of cerebrospinal fluid (CSF), which bathes the central nervous system
•	CSF function
o	Protection
o	Buoyancy
o	Chemical stability

*Cerebral spinal fluid is stored in ventricles in the brain to give the brain buoyancy and
protect the cells from damage from trauma - also provides nutrients to cells.

Question 26

Protection of the brain

• The brain is protected by three….

Answer 26

• The brain is protected by three layers of
membranes known as meninges

o The outer most layer located closest to the
skull is the dura mater
o Just below the dura mater is the arachnoid
layer
o The third most inner layer that adheres to
the surface of the brain is the pia mater
o The space between the arachnoid and pia
mater is the sub arachnoid space and this
area contains cerebral spinal fluid (CSF)

*Strong layers of membranes which provides an extra level of protection of the brain from
damage caused by trauma

Question 27

Midbrain

includes __ and ____

Answer 27

• Involved in maintaining alertness and basic behavioral reactions
o Tectum:
§ Superior colliculi: Involved in vision
§ Inferior colliculi: Involved in hearing
o Tegmentum: Play an important role in attention, arousal, sleep, sensitivity to pain, and movement

*Important structure for diseases involved with vision or hearing damage

Question 28

Hindbrain

includes ___, ___ and ___

Answer 28

• Pons: Relay station from the cortex to the cerebellum (communication station)
• Cerebellum: Involved in movement (find balance and walk)
• Medulla oblongata: Involved in attention, arousal, sleep, and certain reflexes that are necessary for survival (cranial nerves 9–12 are located on the medulla oblongata)

Question 29

Brain Development

Answer 29

• Regions of the brain that are associated with early survival behaviors (e.g., sucking, swallowing) are more developed at birth than cortical regions that are involved in higher-order cognitive processes (e.g., executive functions, problem solving)
• Overtime through experience & learning brain regions associated with higher order function begin to develop, connections are made, areas become more specialized and less diffused.
• Evolution gives them brain structures for survival skills, this provides them with tools to survive, and adapt to their environment and brain structures to form.
• The connections people make will vary based on the experiences you have (i.e., childhood experiences, education influences which ideas are connected together; more use of specifc skills increases connection in that brain region)
• 87 billion cells in the brain, with 100 trillion connections.
• Neuroplasticity is greater in children, then lessens and stabilizes in adulthood. Overproduction of synapses and calls in childhood which get pruned before adulthood.
• E.g., A second language learnt in childhood that you do not use will be discarded (pruned) in adulthood. That’s how the brain deals with changes in the environment.

Question 30

(7) cell types

Answer 30

• Neurons: Specialized for communication
(transmitting information, if neurons die it
doesn’t regenerate)
• Glia: Ancillary functions, such as providing
structure and support to neurons (helps
transduction of information, remove dead
cells, blocks unwanted substances in blood
from entering the brain, generate myelin,
can die and regenerate).

o Macroglia
§ Astrocytes – (provides cells with structure &
nutrients by removing brain debris,
transporting nutrients and removing dead
neurons)
§ Oligodendrocytes –(produces myelin
sheath on axons in CNS)
o Microglia (removes dead neurons)
o Why broca’s damage has such bad effects,
damage to the network is not regenerative.
Would need to use neurons nearby
damaged area (in older people rather than
children).

Glia
• Physical contact with blood vessels
(protective barrier so toxic substances do
not penetrate the brain)
•Astrocytes transport substances from the
blood to the neurons

Oligodendrocytes
• Form a protective sheath, known as myelin,
around the axon
• Insulate and facilitate the transduction of
messages sent from one neuron to another

Question 31

(4) types of Neurons

Answer 31

Types of Neurons
• Motor neurons: Have axons that project to the spinal cord where they communicate with other motor neurons that innervate muscles and glands
• Sensory neurons: Convey information from the peripheral nervous system to the CNS, such as sights, sounds, taste, and tactile information
• Principal neurons: Have long axons that extend to other locations in the brain far away
• Interneurons: Most abundant neurons, have shorter axons that communicate messages to nearby cells and convey information between sensory and motor neurons

Question 32

Parts of a neurons

Answer 32

• Cell body (soma): contains the nucleus and other structures that help a neuron process and transmit information
• Dendrites: Emerge from the cell body of the neuron and receive messages from other neurons
• Axon: Transmit messages to other cells
• Each neuron receives approx. 10,000 signals. If excitatory threshold is meet a neuron will fire.

Question 33

what’s a soma?

Answer 33

cell body

Question 34

Synaptogenesis – origin of synapses (connection

Answer 34

• Early development has an overproduction of synapse, as people develop into adolescence pruning occurs where unused connections are removed this stabilizes in adulthood – means that adults have less neuroplasticity than children.
• Neurons differentiate into different sizes and shapes, and align themselves with other neurons in the same vicinity to form networks, a process known as aggregation
• After birth, during the first one to two years, synaptogenesis increases dramatically and is followed by a substantial reduction, or pruning phase
• The synaptic pruning process depends on genetic and non-genetic factors, and it has been purported that those synaptic connections that are used and reinforced will evolve, while other idle synapses will not survive—i.e., Hebbian Synapses (neurons which fire together wire together – the rest get pruned).

Question 35

Synapses

Answer 35

• The human brain contains more than 100 trillion synapses
• The number of synapses declines as part of the normal aging process
*Synaptic decline is also characteristic of neurodegenerative disorders!

Question 36

Apoptosis

Answer 36

Apoptosis
*Highlights that in addition t synapses neurons can also be pruned
• Neurons are overproduced prenatally and subsequently die off before and after birth
• It has been estimated that approximately 50% of neurons follow a programmed cell death, and this process continues during childhood and puberty

*Scientists have hypothesized that an overproduction of neurons and subsequent competition
for synapses increase the likelihood that an appropriate number and degree of complexity
among synapses will be achieved – remove the duds to make stronger, richer networks

Question 37

Brain Growth and Neuroplasticity (IMPORTANT TO KNOW)

Answer 37

• During prenatal development, the brain
produces approximately 250,000 neurons
per minute
• At birth, the brain has accumulated billions
of neurons
• Glial cells continue to reproduce
throughout life
• Reproduction of neurons was believed to
be complete before birth, but …
• Hippocampus of adult humans
• Olfactory bulb of humans
• At birth, the newborn’s brain is nearly two-
thirds the adult size but only 25% of the
adult weight (smaller)
• After age 5, however, total brain size does
not increase significantly
o The brain’s weight, however, increases
fourfold from birth to 10 years

*Weight increases as synaptic connections increases; size doesn’t increase much during this time.

Question 38

Brain development

Answer 38

• Prenatal brain development is initiated as a result of genetic factors, but environmental factors play a significant role during prenatal and postnatal development
• The key to individuality, therefore, is not to be found in the overall organization of the brain (same across people), but rather in the fine-tuning of the underlying networks” (specific connection within brain will vary across people based on different experiences - environment)
• i.e., ACE’s led to abnormal brain development
• i.e., education and different cultural environments lead to different connections made within the brain
• i.e., enriched environment leads to richer networks
• Children who are maltreated have elevated levels of stress hormones that are toxic to the hippocampus
• Sensory stimuli, diet, stress, hormones, and drugs all affect the developing brain

*Significant decreases in thickness of cortical gray matter and volume loss in children with symptoms of depression is nearly twice the rate of children without depression symptoms

Brain development (Benefits)
• Rats reared in enriched, complex environments show increased complexity of neuronal connections as well as superior task performance compared to rats reared in less stimulating environments
• The area of the cortex that sub-serves the fingers is larger in musicians who play string instruments than in non-musicians

Question 39

Plasticity

Answer 39

• The process of the brain’s ability to change in response to environmental experience, whether positive or negative, is known as plasticity
• Brain plasticity is often characterized by structural and functional changes at both the cellular (e.g., increased dendritic spines) and global (e.g., increased blood flow) levels
• Plasticity declines in adulthood, but the brain remains capable of responding to environmental experiences throughout the life span

Question 40

Traumatic Brain Injury (TBI)

Answer 40

• Insult to the brain that disrupts normal brain functioning and results in temporary or sustained impairments in cognitive, emotional, behavioral, or physical functioning
o Everyday 153 people in the United States die from injuries that involve a (TBI)
o Men have more than twice the rate of TBI-related deaths than women (men > women)
• The effects of the injury vary depending on the location and severity of the injury, age and timing of treatment interventions
• Behavioral and academic outcomes are poorer for children with moderate to severe TBI
• Unfavorable family circumstances (high stress, economically disadvantaged) are associated with a poorer prognosis
• Recovery of behavioral and cognitive function is likely the result of focusing on specific and desired behaviors, and providing a stimulating, enriched environment that leads to synaptic and neuronal changes

Question 41

Stroke

Answer 41

Stroke
• Sudden disruptions to the blood supply to the brain by either a blockage or hemorrhage that cause damage to brain cells
• Thrombosis occurs when a substance forms a plug that blocks blood flow
• The loss of blood flow to the brain restricts the supply of oxygen and glucose to brain tissue (can cause tissue to die and release toxins)
• Compared to adults who suffer a stroke, children tend to have fewer long-lasting behavioral effects such as facial weakness and difficulties with walking (neuroplasticity)
• Approximately 50% of children experience chronic problems with speech, movement, and learning, but the effects tend to be mild relative to adult impairment
• The mechanisms responsible for varying levels of recovery include
• Reorganization of neuronal pathways at the cortical and subcortical levels
• Modulation of new and existing synapses
• Generation of new cells (neurogenesis and gliogenesis)
• Generation of new blood vessels (angiogenesis)
• Sprouting and growth of new axons
• Development of new motor networks

Question 42

Lesions

Answer 42

o Injury-related changes in brain tissue that affect functioning
o Brain injury that severely damages language-related regions results in permanent or transient language deficits in adults, but the prognosis is more positive in young children
o Lesions that occur prior to the onset of language, are associated with normal development of language
*Lesions can be cause by trauma, stroke, tumors etc.

Question 43

Hemispherectomy

Answer 43

• A hemisphere is completely or partially removed
o Hemispherectomy in children: Develop language in the intact hemisphere
o Hemispherectomy in adults: Severe language-related deficits

*Children process language more diffusely, and language is not yet localized in the left
hemisphere as is typically characteristic of adults

Brain Development
• The child brain, relative to the adult brain, is thought to have more synaptic connections available for recovery and reorganization (neuroplasticity)

Question 44

Cross-modal plasticity

Answer 44

• Individuals who are born deaf or blind
o Areas that are normally used for hearing become devoted to vision (in deaf people)
o Somatosensory cortex that controls fingers is significantly larger in blind adults who are experienced Braille readers (more activation in blind than seeing or death people)
o People born deaf had no auditory input in early childhood when brain is being organized, rather than just removing the entire visual cortex, it fills it with other sensory modality neurons such as vision instead.
o People born blind, rely heavily on using their fingers to read brail so the somatosensory (touch) cortex that controls the finger is larger in blind adults who read a lot of braile.
• Video:
o Ben had his eyes removed when he was three but has taught himself to see with sound.
o He never uses a cane, guide dog or cane.
o He uses echo location – makes sharp click noises, the sound waves bounce off of objects and his ears are sensitive enough to pick it up.
o He reorganized his brain, very complex and developed auditory system
o Adapted to his environment.

Question 45

Ramachandran’s hypothesis (phantom limb & transgender)

Answer 45

Ramachandran’s hypothesis
• Reorganization of synapses at the level of the cortex is possible in the adult brain
o These changes can occur in response to environmental demands
§ Mediated by other variables such as age
o Phantom Limb Syndrome:
§ Car accident and loose hand. Phantom limb pain – The loss of limb occurs so quickly that the brain didn’t have time to reorganize itself properly and accommodate the missing limb because it hasn’t received sufficient visual feedback. People experience pain in the missing limbs i.e., the brain tell us our thumb is still in a painful position from the. The brain believes the hand is there and sends signals to the neurons which map the hand to move it and try to alleviate the pain, but you can’t move a missing limb. So, they used mirrors to make it look like he was moving the limb and provide visual feedback to the brain to trick it into thinking the limb was fine and get the pain to stop (visual feedback to modulate pain signals). If you do this enough the brain begins to change its network and the phantom pain stops.

Question 46

Deprivation studies

Answer 46

Experiment:
• College students were paid to remain in an isolated, soundproofed room, lying on a bed with their eyes, ears, and extremities covered. Most participants became distressed after a few hours and very few could remain for the duration of the study
o Participants reported visual hallucinations
o It has been argued that solitary confinement of juveniles is a form of child abuse
• ACE’s leads to abnormal brain development, deficits and disorders
• Social isolation (extreme deprivation) in early childhood can create irreversible language & comprehension deficits in children because they didn’t receive sufficient social interaction in the critical learning period – can’t be leanrt passed this time. The brain doesn’t make these connections or develop these structures and are pruned because they were never used. Children can learn some skills if placed in an enriched environment but will never be able to, in extreme cases, function like normal children (learn grammar etc.).
• Reaching behavior and attentiveness in institutionalized infants reared in non-stimulating environments
o Study in Romanian orphanages
o Decreased metabolism in several areas of the cortex, particularly the prefrontal cortex
o Problems with attention, impulsivity, and social skills
• It has been argued that child maltreatment should be regarded as “an environmentally induced complex developmental disorder”
• Childhood maltreatment interferes with normal development of the limbic system and connections with the prefrontal cortex, which in turn results in an impaired ability to regulate emotion and behavior
• Strong relationship between child maltreatment and reduced hippocampal volume and depression in adulthood

Question 47

Enrichment studies

Answer 47

• Complex environments, relative to simple environments, are associated with increased connections among synapses, dendritic and axonal expansion, and increased white and gray matter
• These physiological changes are associated with improved behavioral performance on learning and memory tasks in other animals and in humans
• “Characterized by consistent and positive emotional support, stimulation that is multisensory, relatively stress-free, promotes exploration and active learning, is reasonably challenging, encourages social interactions, and practices good health care”
• Although these suggestions make intuitive sense, little empirical information is available about the relative contribution of enriching experiences to physiological changes in the human brain
• Brain responses to spoken and written language in adults of variable literacy
o Illiterate
o Became literate as adults
o Literate in childhood
• As literacy increased, increased activation and reorganization occurred in specific regions of the left hemisphere as well as the occipital cortex
• These findings supported that both childhood and adult education targeting reading and writing can profoundly change cortical activity and organization

Enrichment studies (marketing)
o	“The quest to optimize brain health has become a global business, empirical studies are sorely needed to explore the effectiveness of these methods”

Question 48

Long-term potentiation (LTP)

Answer 48

• Increased excitability of a neuron in response to repeated stimulation
• Increased excitability of cells over time is thought to result in more efficient communication among neurons
• More efficient communication among neurons is associated with enhanced learning and memory

Question 49

Medication, Neurotrophins and Neurogenesis

Answer 49

•	Researchers have explored the role of various medications in facilitating plasticity with regard to recovery from brain injury
o	β-Adrenergic receptor blockers
o	Acetylcholine agonists
o	Stimulants
o	Antihypertensives
o	Hormones
    …
none have emerged as reliably effective at promoting neuroplasticity

Question 50

Neurotrophins

Answer 50

Neurotrophins
• Family of proteins that induce the survival, development, and function of neurons
o Neurotrophins promote the sustenance for the survival of neurons and induce synaptogenesis
§ Nerve growth factor (NGF)
§ Neurotrophin 3 (NT-3)
§ Transforming growth factor (TGF)
§ Epidermal growth factor (EGF)
§ Mesencephalic astrocyte-derived neurotrophic factor (MANF)
§ Brain-derived neurotrophin factor (BDNF)
• Reduced levels of neurotrophins in postmortem brains of individuals with various disorders such as Alzheimer’s disease, Parkinson’s disease, and depression
• Decreasing levels of neurotrophins (BDNF) is an early symptom of Alzheimer’s disease

Question 51

Mechanisms of neuroplasticity

Answer 51

•	White and gray matter changes
•	Proliferation of glial cells
•	Dendritic arborization
•	Increased dendritic spine density
•	Axonal sprouting
•	Increased myelination
•	Cell metabolism changes
•	Increased production and release of neurotrophins
•	Synaptogenesis
•	Neurogenesis
•	Angiogenesis
*Remains poorly understood!

Question 52

Brain imaging, structural or functional

Answer 52

Brain imaging
• Structural
o what is does the brain structure look like & how does it correspond to a condition (MRI, CT, DTI)
o Homicide in prison correlated with structural (not functional) changed in the brain relative to non-prisoners. E.g., brain ridges are smaller in specific regions.
• Functional
o What metabolic processes occur in the brain? Changes in electrical charge, blood flow etc. which correspond with a given condition (fMRI, PET, SPECT)
o Example: Epilepsy is characterized by excessive neuronal firing

Question 53

Structural imaging: Computed Tomography (CT)

Answer 53

• Diagnostic imaging test used to create detailed images of internal organs, bones, soft tissue, and blood vessels
• The scan generates cross-sectional and three-dimensional images using an X-ray
• Used to research a number of psychiatric and neurodegenerative diseases
• Schizophrenia
• Anxiety disorders
• Alzheimer’s disease

Question 54

Structural imaging: Magnetic Resonance Imaging (MRI)

Answer 54

• A strong magnetic field is passed through the skull, and the MRI scanner detects the movement of hydrogen molecules in response to the magnetic field
• MRI brain scans have found morphological deviations in individuals with schizophrenia (e.g., enlarged lateral and third ventricles, reduction of total brain volume, reduction of size of prefrontal and temporal lobes)

Question 55

Structural imaging: Diffusion Tensor Imaging (DTI)

Answer 55

• Analyzes the movement of water molecules in the white matter
o Myelinated axons of the brain (structure)
• CT and MRI look at the whole brain structure. DTI can be used to only look at the connectivity between neurons, rather than one area of the brain being bigger/smaller than the other. DTI to look at connections, cables in the brain, higher density of connections between certain brain regions. Doesn’t tell us about neuron bodies it looks at the myeline (white matter).

Question 56

Functional Imaging: Functional Magnetic Resonance Imaging (fMRI)

Answer 56

• Inception in the early 1990s
• Provides information about brain functioning indirectly based on changes in blood flow and oxygen consumption
• More blood and oxygen = more activation
• “Neurons in a specific brain region become more active, and the cell’s mitochondria require more glucose for production of cellular energy: Glucose and oxygen are delivered to cells via the brain’s vascular system; consequently, changes in regional blood flow reflect areas of increased neuronal activation”
• Scenario: can use fMRI to decide whether people are in a vegetative state or not. Is there still brain activity in response to stimuli? Place comatose patient in MRI machine and get them to visualize physical scenarios (i.e., dancing) and see if brain activation occurs in the motor cortex. Shows they can hear, understand and execute instructions. Profound scientific information to make deciding wether to pull the plug easier for families.
• fMRI
• Takes up to several seconds (quick but loud)
• Good spatial resolution (very detailed images)
• Poor temporal resolution (blood flow delays it up to 20 sec; very slow compared to millisecond neural transmissions)

Question 57

Default Mode Network

Answer 57

• There may be a baseline or normal resting state of brain function that involves consistent activity in some areas and less activity in others
o Even at rest, the brain is involved in a continuous process of monitoring the environment and this monitoring is correlated with neuronal activity in certain brain regions

*People are not all the same & do not have the same default baseline state. Am I comparing
apples with apples or apples with organs? Is it a real difference in brain function or
structural differences or just individual differences?
*can do rsFC – resting state neural activity in fMRI

Question 58

Functional Imaging: Positron Emission Tomography (PET)

Answer 58

• Organic substances, such as oxygen and glucose, are bombarded with radioactive isotopes
• These compounds are “radioactive” and shed positively charged particles (positrons) that can be traced in the brain with neuroimaging techniques
o Glucose metabolism
o Blood flow
• Glucose is the primary source of energy for neurons and, as neuronal activity increases, increased amounts of radioactive glucose are taken up by neurons
• Organic molecules, such as oxygen or carbon, can also be tagged and traced in the blood

*Will be able to see what areas of the brain the oxygen and glucose are binding to and using
(Higher activation in specific areas)

Question 59

Functional Imaging: Electroencephalogram (EEG)

Answer 59

• measures electrical charge in cortex (not subcortex)
• Records the postsynaptic cortical activity of neurons while an individual is at rest, sleeping, or during a specific sensory stimulation task
• During an EEG, electrodes are placed on the scalp over different regions of the brain
• Voltage changes are recorded, brain activation correlated to task being done
• Good temporal resolution (neural activity is very fast, no delay)
• Poor spatial resolution (cannot focus on specific brain regions, nearby neurons may contaminate it)
• Can use EEG to identify people with or at risk of dyslexia? Normal diagnosis age is 9-10 years old. Studies with new-borns (24 hours old) play sounds with eeg machine to see if their auditory region of the brain responds as normal to detect with 85-90% accuracy if they will develop dyslexia.

Question 60

Functional Imaging: Real-Time Functional Magnetic Resonance Imaging (rtfMRI)

Answer 60

• Technology has recently enabled the use of faster, immediate, “real-time” functional imaging combined with neurofeedback to help individuals decrease or increase areas of activation in the brain
• i.e., visual image of thermostat or bar changing etc.

Question 61

Functional Imaging: Optical Imaging: Near Infrared Spectroscopy (NIRS)

Answer 61

• Participants wear an fNIR sensor mounted to the forehead that detects changes in concentrations of oxygenated blood (i.e., metabolic)
• Can be used with higher risk populations, such as infants
• Cheaper method which doesn’t require a magnet like other techniques

Question 62

(3) Limitations of functional neuroimaging studies
(5) solutions
(1) validity concern

Answer 62

Limitations of functional neuroimaging studies
• Methodological factors
• Statistical analyses (i.e., Multiple uncorrected comparisons can lead to type 1 error (false positive) and misleading conclusions)
• Lack of standardized procedures

Solutions
• Statistical analyses should be theoretically based and determined a priori
• Statistical corrections procedures need to be implemented to avoid spurious findings
• Move away from a strong localization of function to understanding patterns of activation
• A standardized set of approaches for fMRI connectivity modeling needs to be developed and implemented
• Improvement of sample size and statistical power, multi-site, and data-sharing studies should be conducted

Validity is questionable! Am I measuring the construct I intended?
• participants may approach tasks differently, and various memories may be triggered while a subject is performing a task. Consequently, the results may not reflect a specific cognitive process but instead additional brain functions. Hence, measurement of complex constructs such as “personality” and “novelty seeking” using PET or other neuroimaging techniques is questionable”

Question 63

(9) Brain Stimulation Techniques

Answer 63

• Deep brain stimulation (DBS)
• Electroconvulsive therapy (ECT)
• Magnetic seizure therapy (MST)
• Transcranial magnetic stimulation (TMS)
• rapid TMS (rTMS)
• Transcranial electrical stimulations (tES)
• Vagus nerve stimulation (VNS)
• Optogenetics

*Stimulating the brain and measure behavioural responses. Methods to try and eliminate
symptoms of psychiatric, neurodivergent disorders. It helps us validate what actions specific
areas of the brain control.

Question 64

Electroconvulsive Therapy (ECT)
Mode of action?

Answer 64

• Developed in the 1930s as a treatment for schizophrenia
• Placement of electrodes on the scalp to deliver electricity to the brain, inducing a grand mal seizure
• sessions required for improvement of symptoms ranges from 6 to 12
• Mortality rate of ECT is approximately the same as that of minor surgery
• Found to improve symptoms associated with a host of disorders—major depression, bipolar disorder, and schizophrenia, as well as bulimia

*Severe depression treatment – electrical charge reboots brain system. Sometimes we do
not know what to do to fix it other than send electrical current between left & right
hemisphere. People used to remove prefrontal cortex with ice pick during lobotomies in the
olden days. Left people in vegetative state. Non-surgical.

Mode of Action
• Unclear!
• Theories:
o Impacts dopaminergic, noradrenergic, and serotonergic transmission
o Facilitate dopamine binding to postsynaptic receptors
o Enhances transmission among GABA-releasing neurons and triggers genetic expression of nerve growth factor production

Question 65

Transcranial Magnetic Stimulation (TMS) and Repetitive TMS (rTMS)

Answer 65

• Stimulates specific areas of the cortex while an individual is awake
• Magnetic field produces electrical currents in the brain by depolarizing neurons
• Head-mounted wire coils that deliver strong magnetic pulses to wide or specific areas of the scalp
• Approved by the FDA in 2013 for treatment resistant depression
• Non-surgical
• Mode of Action
• Varies by:
o Activity an individual is engaged in
o Region stimulated by the techniques
o Parameters of the devices (e.g., intensity, frequency, coil angles)
o Individual differences among participants

*Find right voltage needed to reach brain by stimulating motor cortex first, to see movement,
then use it on the brain region of interest.

Question 66

Transcranial Electrical Stimulation (tES)

Answer 66

• Send weak electrical currents to the brain via electrodes placed directly on the scalp
• Stimulation varies from 5 to 30 minutes
• Minimal side effects
• Treatment of motor symptoms of
Parkinsons’s disease, memory
impairment in Alzheimer’s disease,
chronic pain, and epilepsy
• Uses electrical current not magnets
• Nonsurgical

Question 67

Optogenetics

Answer 67

• Involves the use of light to activate
specific ion channels in cells
• Give mice a viral injection, use blue or
yellow light to inhibit the activity of neurons, measure the brain activation of infected cells.

Question 68

Vagus Nerve Stimulation (VNS)

mode of action?

Answer 68

• Involves the surgical placement of an electrode wrapped around the left vagus nerve located in the neck
• The vagus nerve is one of the 12 pairs of cranial nerves
• The lead and electrode are connected to a battery-operated pulse generator implanted in the left side of the chest
• Seizure reduction in patients with epilepsy and improves mood
• Tinitus (phantom pain or ringing in the ears which happens in the brain). Use VNS to rearrange cortical distribution of the neurons in the auditory system. Stimulation paired with various tones, caused cortical architectural changes of noise to get rid of tinitintus.
• Mode of Action
• Modulation of synaptic activity in the locus coeruleus, thalamus, limbic structures and cerebellum
• Increased excitability of noradrenergic, serotonergic, and GABA projections throughout the brain

Question 69

Deep Brain Stimulation (DBS)

Answer 69

• Surgical insertion of a small lead with an electrode in specific target areas of the brain
• The lead and electrode remain in the brain and are connected to a programmed, battery-operated pulse generator implanted in the chest
• Similar to VNS, the generator sends electrical impulses, but in DBS, the impulses are sent directly to the target region of the brain
• *Treat Parkinson’s by target in substantial nigra cortical region
• improve tremors characteristic of movement disorders, such as Parkinson’s disease
• Effective at decreasing obsessive-compulsive behavior in treatment resistant cases