- moving vehicle accidents most common reason for traumatic brain
injuries, occurring more frequently in males than females
What is Clinical Neuropsychology?
clinical neuropsychology- division of psychology that specializes in the
clinical assessment and treatment of patients with brain injury or neuro-
cognitive deﬁcits. it is considered an applied ﬁeld because it deals with
assessment, diagnosis, and treatment of those individuals with brain illness
or injury as opposed to only looking at brain functions and structures.
experimental neuropsychology- ﬁeld of psychology that focuses on
brain-behaviour relationships usually using animals as subjects. it does so
by describing structures and functions, rather than focusing on
assessment, diagnosis, treatment.
- dates back to beginning of 20th century. the term neuropsychology ﬁrst
used by Sir william Osler. Even though the ﬁeld is relatively recent, study of
brain, goes back to civilization.
Ancient Hypotheses to Modern Theories of Brain Functioning
Neolothic Period or Stone Age
trephination- oldest known surgical technique in which small piece of bone
is removed from skull, leaving a hole in the skull, the procedure has been
done for medical and religious reasons. It was done on people who were
not accepted by their culture, such as hallucinators, schizophrenics, to
release the evil spirits.
- it removes a bony portion of the cranial vault. clearly its a crude way to
treat brain bc it involves exposure of brain tissue to elements and various
forms of disease and infection. surgeons performing this procedure though
were skilled and aware of the infections it could cause.
3rd dynasty, not really advanced in their understanding of the brain.
- during mummiﬁcation, brain was discarded even though all other organs were felt to be important
- Imhotep, founder of Egyptian medicine and original author of papyrus.
- Edwin Smith Surgical Papyrus- early Egyptian manuscript which
described techniques used to treat various forms of difﬁculties including
brain trauma. it is one of the ﬁrst brain-behaviour relationship- a
relationship that exists between certain functions of the brain and overt
- papyrus from Smith contained 2 sections, one was authentic and the
other was not.
- James Breasted read the document in 1930, which showed no
indications on surgeries performed, gave reference to CSF. there were no
operating procedures involved, but ways to reduce intracranial
hemorrhaging, removal of fragments of bone from ear canal andblood clots
- it also contained prescriptions for head wounds, using fats from different
- Eber papyrus contains 900 prescriptions for ailments in various parts of
body, using different ingredients including urine and feces. this papyrus
contained more supernatural forms of healing than Edwin Smith
-Herophilus and Erasistratus of Alexandria were ﬁrst individuals to
propose brain as a centre of reason, by providing ﬁrst accurate description
of human brain, including ventricles. they conducted most work on
cadavers and used criminals for vivisection, dissection of body while it is
- new theory in Middle Ages, claiming that ﬂuid0ﬁlled compartments of brain
were responsible for higher menta, as well as spiritual processes. cavities
were thought as cells, lateral ventricles forming ﬁrst cell, third ventricle
second, fourth ventricle third.
ventricular localization hypothesis- hypothesis that mental and spiritual
processes reside within ventricular canals, later called "cell doctrine."
- today we know that ventricles are sites that produce and transport CSF,
which cushions brain within skull, made in choroid plexuses, ﬂows through
ventricles and subarachnoid space.
- Heralitus, called mind an enormous space whose boundaries we could
never reach. he believed that universe is in constant change and there is
an underlying order or reason to the change.most signiﬁcant philosopher of ancient Greece before Socrates and plato.
- Pythogoras, suggested brain was organ responsible for human thought
helped form brain hypothesis- hypothesis that brain is the source of human
thought and behaviour.
- Pythogoreans followers of Pythogoras, believed in natural science and
philosophy. they lived together in group and followed ethical code of
- Hippocrates, best known for hippocratic oath- an agreement that
Hippcrates demanded of physicians ensuring that they would do no harm in
their quest to appropriately treat their patients
- he believed that brain controlled all sensing and movements, and
indicated that damage to one side of brain affected other side of body, aka
- practised holistic medicine- treats entire patients, involves physical,
psychological, spiritual aspects of healing.
- Plato believed that soul was divided into three functions; appetite, reason,
and temper, all residing in the brain, because the brain was close to
- he imposed many mind-body question- philosophical questions
regarding the relationship between the physical body and the spiritual mind.
- credited with earliest reference to mental heath, as he suggested that a
balance between all pats of life lead to good metal health
- Aristotle, believed brain was without blood and functioned to cool hot
blood as it came from the heart. he designed the cardiac hypothesis= that
heart is centre of rational thought
- Galen misunderstood ventricles and believed in ventricular localization
theory; thinking that they housed animal spirits, produced in the chroid
plexus. he also believed that functions of body and brain were based on
balance of bodily humours; blood, mucus, and yellow and black bile were
responsible for functioning of body and brain. He was very interested in
study of stroke, called apoplexy a the time. he believed it resulted from
accumulation of black bile in ventricles, or from obstruction of ﬂow of animal
The Middle Ages
- Aristotle's views were considered very sacred until 13th century, Albertus Magnus theorized behaviour resulting from combination of brain structures
including cortex, midbrain, and cerebellum.
- began in italy in mid14th -16th.
- plague was a great factor in start of the Renaissancem leading to freer
inquiry and thought.
- Da Vinci could disprove the ventricular localization theory as he secretly
dissected cadavers, but held to this belief and we do not know why.
- Andreas Vesalius, published ﬁrst accurate book on human anatomy
called On the Workings of the Human Body, one of the most medical
science books ever written. he proved Galen's view as wrong
- believed that to study human you need to dissect human, none believed
his views at the time tho
-Descartes believed in dualism- view that within each person resides two
entities, mind with mental properties, and body with physical properties. this
is the opposite of monoism- view that there is only one basic and
fundamental reality, that all existence is this one reality, hence they operate
according to the same principles.
- he believed that mental processes reside in the pineal gland, bc it was
the only structure not composed of bilaterally symmetrical halves. he
viewed the cortex as a covering of the pineal body.
-Thomas Willis, known for study of blood circulation and for whom Circle
of Willis is named. he used clinical evidence form living patients with
movement disorders, also described sensations residing with corpus
striatum. he stated that cerebral gyro controlled memory and will,
imagination was also cerebral function located in corpus callosum. corpus
striatum was thought tone related to sensations and movement, cerebellum
controlled voluntary/.involuntary systems, and pons/medullla were part of
- he was ﬁrst person in renaissance period to divide brain into functional
parts base on comparative anatomy, theory, and coin practice.
- Emanuel Swedenboorg, concluded cerebral cortex was source of
understanding, thinking, judging, willing. he was not accepted much bc he
began to have visions
18th Century: Localization Theory
Localization of brain functioning- theory that certain abilities are localized to certain areas of brain.
- Gall correlated 27 faculties of mind with skull features and located abilities
on maps of both hemisphere. phrenology- inaccurate theory developed by
Gall which stated that bumps on head related to certain abilities residing
within brain led to belief in reading bumps and increasing abilities by
rubbing corresponding bumps.
- these ideas began to be practiced in salons of Europe.
- Gall was also responsible for discoveries in neuroanatomy and
neurophysiology, some of the earliest views on idea of localization of
- proposed that cortex and sulci and gyro were functioning parts of brain,
not just coverings of pineal body. a large pathway, the pyramidal tract,
leads form cortex to spinal cord, implying that cortex sends info to spin cord
to command movement of muscles.
- his student Johann Spurzheim, worked with him but Spur left bc he felt
there were no bad or evil functions.
- Pierre Flourens disputed that no localization of function within cortex, he
did ablation, a type of surgery in which removing part of the brain led to
generalized, not localized, disorders of behaviour. he claimed that no
speciﬁc localization of ability, rather amount of extent of tissue damage is
what mattered. so basically, the greater amount of impaired tissue, the
more dysfunctional the individual will appear.
- he also sated that brain operated in integrated fashion, not with discrete
functions. he was describing the modern term neuroplasticity- brains
neutral ability to form new connections to compensate for injury or changes
in one's environment.
- this is possible bc brain functions as a whole, similar to the way he
described. he believed that cerebellum was responsible for coordinated
movement and that medulla required for basic life functioning.
19th Century Advances
-scientiﬁc method- method of research in which problem is identiﬁed,
hypothesis is formulated, relevant data gathered, from these data, cause-
effect relationships can be stated.
- Wilhem Wundt created ﬁrst psych lab in Germany.
- through scientiﬁc methods researchers are able to make cause and effect
statements for the ﬁrst time.
- Philliple Pinel, french physician, became head of two asylums, and introduced kindness and humanity in treatment of the patents.
- at the same tim, William Tuke, cared for patients in England. Dorothea
Dix, Eli Todd, Clifford Beers(A Mind that Found Itself: An Autobiography)
- this book is about Beer's experience with bipolar disorder and his
- mental hygiene movement: movement to treat psychiatric patients with
kindness, dignity. it instigated release of mental patients from prison and
the building of mental hospitals.
- moral therapy- created for mental patients based on ideas of mental
hygiene movement; kindness and respect.
- diagnostic classiﬁcation systems- for classifying medical and psychiatric
disorders, it lists symptoms of a particular disorder and various other
important facts for diagnosis; in psychology, refers to DSM-IVTR
- Emil Kraeplin, categorized mental illness as endogenous(curable) and
- Darwin, conceptualized origin of species; survival value
Localization of Brain Functioning Areas: Higher Cortical Areas
- Gall and Swedenborg looked at various types of localization; but it took a
longer time to look into the localization of higher cortical functioning.
- Paul Broca, localization of language within left hemisphere, but his work
was based on other people as well.
- Bouilard found that brain had several social organs, one was related to
speech and difﬁculties with speech, when the organ was damaged.
- Aubertin, his son in law, argued that there were speciﬁc higher order
cognitive functions localized within certain areas
- Marc Dax, french neurologist, discovered link between damage to left
cerebral hemisphere and loss of ability to produce speech, died without
publishing his ﬁndings. then Gustave Dax, his son, published his work with
his own ﬁndings as well, but 6 weeks before Broca did, and they both had
the same ﬁndings
- Broca examined patients who could speak coherently but could not
understand the spoken word.
- area in posterior, lower region of left frontal lobe, became Broca's
area. he also found that language production was in left hemisphere
- lateralization; idea hat certain abilities reside in one side of the
brain or other, for majority of individuals, verbal abilities reside in left h,
spatial abilities in right h, - aphasia; inability to use or comprehend language.
- Carl Wernicke, found second language area of brain
- temporal lobe, to the posterior and inferior to Broca's area, damage
here led to inability to make sense with language even though utterances
were grammatically correct whether spoken or written.
- expressive language located in frontal lobes, receptive language
located in temporal lobe
- damage to nerve ﬁbres connecting Wernicke's and Broca's areas result in
arcuate fasciaculus, resulting in conduction aphasia; inability in both
reception and production of language.
- Broca's aphasia; can understand what is spoken but has difﬁculty
responding in grammatically correct manner (E has this)
- Wernicke's aphasia; can grammatically produce speech with content
inappropriate to question
- Conduction aphasia; neither understands question not responds
- John Huglings Jackson, disagreed with all these aphasias, and saw the
brain as functioning in a hierarchical manner, as each level controls more
complex functions. the three levels were spinal cord, brain stem, and
- Lashley believed in localization and equipotentiality; idea that mental
abilities depend upon entire brain functioning as a whole
- also proposed the principle of mass action basically that the extent of
brain's impairment is directly proportional to amount of tissue damage
- Alexander Luria described each area of central nervous system involved
in one or more brain functions. the ﬁrst area regulates arousal level of brain
and proper muscle tone. second area's role is reception and analysis of
sensory inf from external and internal environments. third was involved with
planning, executing, verifying behaviour.
- Roger Sperryl studied split-brain; conducted on humans with severed
corpus callouss, to determine extent to communication between two
hemisphere. (corpus callosum is a large mass of myelinated axons which
connect left/right hemispheres, and allow communication between the two )
- Ward Halstead developed neuropsych labs in Chicagoe, began
assessing brain impairment. with the help of Ralph Reitan, created the
Halstead0 Reitan Neuropsych Test Battery; designed to be administered
in standardized fashion to all subjects and allowed for comparability between,
- Lurai-Nbraska Battery designed to ﬁt needs of individual patient and
admin of test could be altered to ﬁt individual needs more useful in forensic
The Development of Clinical Neuropsychology as a Profession
- similarities between WW1,2 and brat Depression was cases of PTSD
experienced by individuals
- Veterasns Administation, US Government agency created to service
physical and mental health needs of those who served in armed forces,
- Korean War and Vietnam Conﬂict led to more brain issues. initially leading
to PTSD- mental disorder occurring after traumatic event outside range of
usual human experience and characterized by symptoms like reliving the
event, reduced involvement with others, exaggerated starle response,(aka
shell shock, battle fatigue)
Clinical Neuropsychology as a Subspecialty of Clinical Psychology
-- clinical psychology- branch of psychology devoted to assessment,
diagnosis, treatment of mental and behavioural disorders
- Boulder Model, developed framework for training of clinical
psychologists; guidelines termed scientist-practioner model, which basically
state that to be accredited by APA, clinical or counselling doctoral program
must contain prescribed number of classes or credits in scientiﬁc basis of
behaviour and certain classes/credits in practise of psychology.
- clin neuropsyhcologist is PHD level, with the following:
- completion of systematic didactic experiential training in neuropsych
and neuroscience in uni
- 2 or more years of supervised training applying services in clinical
- licensing and certiﬁcation to provide psychological serves to public by
laws of state/province
- review by one's peers as test of those competencies
- 3 major organizations existing for perpetuation of clinical
neuropsychologyl Division 40, INS, and NAN.
Methodology Speciﬁc to Clinical Neuropsychology
Subjects - main questions for neuropsychologist is type of subject from which
research ﬁndings have ben taken; usually through a cases study method.
Techniques Dealing with Subject Variables
- double dissociation technique- lesions have opposite or dissimilar
effects on two distinct cognitive functions; develop to help determine when
cognitive functions are independent.
- lesion approach; lesioning of animals and sometimes humans to study
effects of lesions of various brain functions. when its used with humans its
usually in areas where individual has difﬁcult for which lesion should help
eradicate the difﬁculty. But for animals, lesions are used to create deﬁcits
and observe functioning afterwards
Imaging Techniques in the Study of the Human Brain
- EEG- record of brain wave patterns as individual complete a task. ﬁrst
and oldest technique to record electrical activity
- evoked potential; ability to record changes in EEG activity in response to
sensory stimuli; response is termed evoked potental/ event related potential
- Xrays- imaging method, radiates effect in density of different parts of
brain to various degrees, a method of enhancing X-ray is
pneumoencephalography; in which a small amount of CSF is removed
and replaced by air. car is taken as air moves up spinal cord, and bc of the
air, the ventricles stand out clearly. tis is a v painful procedure
tho.Angiography, is similar to tis, uses radiopaque substance to allow
visualization of blood vessels.
- CT Scan, based on multiple X-ray images of brain, provides 3D
perspective of brain with clear differentiation of brain structures. the ﬂuids
are a lll diff colours, allows between view of the dysfunctional area.
SPECT- Single Photon Emission Tomography- similar to CT BUT
simpler and inexpensive. basicallyy the emission of single photons of a
given energy form radioactive probes, the emissions are used to construct
images of probes located within body, thereby detailing ﬂow of blood in
given area Dynamic Brain Imaging
- PET-Positron Emission Tomography; visualized brain activity based on
cerebral blow ﬂow; tracks metabolism of glucose, oxygen,
- MRI; Magnetic Resonance Imaging; use of magnetic ﬁelds; gives
clearer image than CT scan, less dangerous bc does not use radiation.
excellent bc it observes brain metabolism and nutrients distribution.
- FMRI is like MRI, allowing detection of increased/decreased blood ﬂow in
particular areas of brain. does not involve radiation exposure.
Intracranial brain stimulation- stimulation of brain tissue used in
treatment of various central nervous system diseases like Parkinson's.
used more as an adjunct to various forms of treatment. difﬁcult is that its
invasive needing skull to open to insert electrode.
Transcranial Magnetic Stimulation- procedure in which brain is
stimulated through skull.
CHAPTER 2- THE NERVOUS SYSTEM: STRUCTURE AND
Central Nervous System
Prenatal Development: External Factors
- Prenatal Development refers to all steps involved with formation of
various structures and functions of body, speciﬁcally central nervous
- proper nutrition is crucial for development of proper CNS, as fetal
difﬁculties like low birth weight, smaller head is caused by malnutrition.
- alcohol/drug consumption is very bad and leads to difﬁculties. fetal alcohol
syndrome, causes cognitive difﬁculties, directly related to alcohol
consumption. Increased stress raises cortisol level in body, basically a
steroid hormone released by adrenal cortex that elevates blood sugar and
metabolism, helps body adapt to prolonged stress. excess cortisol is based
bc it may lead to depression of immune system and commence various
illnesses' in one's body, like pneumonia, bronchitis, etc.
- physical abuse also leads to developmental complications, shaken baby
syndrome, can result from it and lead to traumatic brain injury. this is basically when the baby is shaken so hard that the skull is impacted.
emotional abuse can also lead to developmental issues.
Development of the Central Nervous System (CNS)
dorsal--> superior (towards back or toward top of brain)
ventral--> inferior ( towards belly or bottom of brain)
rostral--> anterior (towards head)
caudal--> posterior(towards rear or away from head)
- germinal period is time between conception and 2 weeks later.
- developing cells are called zygote, end of 1st week blastocyt is formed, a
mass of cells with ﬂuid centre. it includes the trophoblas, which provides
nutrition. after implantation, it is an embryo, and embryonic stage ends until
ﬁrst trimester. it has 3 layers; ectoderm; outermost, develops into skin,
sense organs, nervous system. mesoderm; middle layer,becomes
muscles, blood, excretory system. endoderm; innermost later, digestive
system, lungs, other internal organs. Amnion is a sack of ﬂux in which
embryo ﬂoats for temperature regulation and protection. umbilical cord
connects embryo to placenta, a group of tissues in which blood vessels
from embryo and mix but don't join.
- development of nervous system begins with neural plate; made of
ectodermal tissue on dorsal surface of developing embryo. it is induced by
signals from mesoderm later. as it becomes evident, cells are totipotent,
able to become any cell in the body, and as it develops, the cells lose this
ability and become speciﬁc to central nervous system development. within
time, neural plate folds to form the neural groove, and the lips of the groove
fuse to form the neural tube, which become the spinal canal and cerebral
ventricles, while the swellings at the end of the tube become the forebrain,
midbrain, and hindbrain.by the24th day after conception. By the end of 7
weeks the embryo is a "fetus". neural crest, dorsal to neural tube, formed
form cells that differentiate from tube as its being formed. these cells
become neurone and glial cells of peripheral nervous systems. the brain is
almost a complete replica in 100 days.
Prenatal Neuronal Development
- Induction; begins when part of ectoderm becomes nervous system. since
cells are totipotent, they are stem cells. Proliferation time of immense
cellular division, occurs once neural tube is formed, also called neurogenesis, since its the beginning of development of neuron and occurs
for ﬁrst 5 months of gestation. Cell migration happens after the ﬁrst neurons
are developed, and continues several weeks after neurogenesis is
complete. Once they migrate, they aggregate, which means they move
toward other cells that have migrated to similar area to form nervous
system structures. after this, axonal dendritic, and synaptic formations
occur, aka maturation. The axon(sending end of neurone) forms at the
arrival at the appropriate surrounding neurone. a single neurone can grow
an axon but it takes two neurone and coordinated effort to create synapse,
and the formation of synapses is synaptogenesis, a process carried out
through life, but mostly early periods of development. so basically, uhhh..
neurone form axons before they have any other neurone or muscle tissues
with which they link, but not all primitive neurone form these bonds.
Bonding depends on levels of nerve growth factor, which promotes survival
and growth of a neurone. its released by organs with which neurone has
begun to form a synapse. if a neurone does not receive nerve growth
factor or does not bond correctly to receive factor, it will begin the
preprogrammed process of nerve cell death, also called apoptosis, and
degeneration after a certain time. after this death, the space left on the
postsynaptic membrane is ﬁlled by sprouting axons of living neurone,
leading to a massive rearrangement of synaptic connections.
- after 12th week, brain becomes more like adult brain, most noticeable
characteristics are ventricles, developed butterﬂy shape. other
subdivisions: telencephalon, diencephalon, mesencephalon,
- building blocks of CNS.
- soma; cell body that contains all of the organelles, is where they
assemble proteins, generate energy, maintain metabolism.
- Nucleus, centre of the neurone containing DNA, the genetic code of a
human. each strand of DNA contains chromosomes, which are strands of
nucleotides, paired together, forming genes. The remainder of the cell is
made up of cytoplasm, internal ﬂuid that holds organelles in place within
the cell. Mitochondria also reside in body of cell, site of energy production,
aka power plant. Within it are fats, sugars, proteins from food that react with oxygen and produce adenosine triphosphate, energy source for
neurone and other cells, consists of adenosine bound to ribose and three
- endoplasmic reticulum, network of tubules within cell that transports
synthesized lipids and membrane proteins to other locales. its composed of
smooth and rough ER, smooth doesn't have ribosomes, important for
synthesis and production of lipids used in carb metabolis, detoxiﬁcation of
cell from drugs and poison. rough has ribosomes, which synthesize
- so proteins are either sent to places where needed or to Mr. Golgi
Complex ova here, which basically is a system of membranes that package
molecules into vesicles, which are easier at being transported. lysosomes,
contain digestive enzymes, provide neurone help in recycling and reusing
materials, and microtubules quickly transport materials within neurone.
- RNA is like DNA but it has nucleotide base instead of thymine, and
phosphate and ribose backbone instead of phosphate and deoxyribose. t
carries genetic code from buckles of cell. neurone are covered by a cell
membrane composed of lipid bilayer, made of two layers of fat; allows
selective permeability to certain substances. its made up of hydrophilic
exterior, that attracts water, and interior, which repels water
OK WAJIHA THIS SHIT U NEED TO KNOW KNOW NOW.
-neuron ﬁrst receives signal from another neurone at dendrites, which are
structures that receive info and send it to the body of the neurone. neurone
can have many, that branch to other neurone and act as message
receivers, bringing chemical and electrical info. the primary task is to relay
an electrical message to the soma, or the body of the neurone. the
dendrites are also divided into segments, called orders, named based on
their location in relation to the soma. axons are at the opposite end of the
cell, they sent info from soma to the presynaptic terminal. signals travelling
through axon go in one direction, and usually only one axon per neurone,
but they may have many branches, which leave the some distance from the
cell body. The axon hillock,is where an impulse/signal is determined to be
strong enough to be sent down axon and to next cell, if depolarization and
hyperpolzarization reaching it is sufﬁcient to depolarize membrane to a
level called threshold of excitation, then action potential occurs, which is
the massive momentary reversal of the membrane potential from -70 to
+50, synonomous with ﬁring of neuron. The all or nothing principle happens here, so basically signal is strong enough to produce the action potential, or
- after this, a brief period called the absolute refractory period occurs,
where its impossible of another action potential to take place. the neurone
must return to its initial resting potential and reset itself before it can ﬁre
again. there's also a relative refractory period, where the neurone can
respond to series of impulses that have a greater depolarization charge,
this is where the neurone starts to depolarize, but does not reach resting
potential; so it needs large stimulus or series of stimuli
- myelin sheath, fatty substances that covers the axons and speeds
conduction, its produced by oligodendrocytes in CNS and Schwann cels in
PNS, Schwann are only cells capable of guiding axonal regeneration. thus
axonal regrowth only happens in PNS. Along axon are gaps without
myelin, called nodes of Ranvier, which also help in transmission and allow
impulse to skip or jump along length of axon, the electrical movement here
is saltatory conduction. At the end of the axon is a gap between neurone,
called a synapse, junction across which nerve impulse passes from axon
terminal to a neurone, muscle cell, or gland.
- at the end of axon projecting on synapse is the synaptic vesicles, which
store neurotransmitters, and release them into the synapse when the nerve
impulse reaches the synapse. Neurotransmitters are the proteins packaged
and stored by Golgi bodies in vesicles infused by microtubules to gather at
terminal ends of axon. they gather and await on action potential, and often
neurotransmitters are next to active zones, areas of protein accumulation in
membrane that allow vesicles to deposit contents into the synapse.at ﬁrst
only info is passed through dendrites, passed to soma and down axon to
synaptic vesicle, electrical, but when neuropterans is released its chemical,
so the process is now electrochemical.
- Otto Loewi and henry Dale discovered neurotransmitters.
2 categories; excitatory; increase likelihood of action potential in
postsynaptic neuron; glutamate is most frequent
inhibitory; decreases likelihood of action potential in
postsynaptic neuron; GABA is most frequent
- process of neurotransmitter release is exocytosis, small ones, when
excited by action potentials, open voltage-gated calcium channels, which
are released as pulses each time in an action potential triggers inﬂux of
calcium ions. Peptide neurotransmitters, released in response to increase of Calcium, and then neuropterans sent signal by binding to receptors in
postynaptic membrane. Each receptor is a protein that has binding sites for
certain neurotransmitters. A molecule that binds to another is called a
- Ionotropic receptors, associated with lingand-activated ion channels,
opens immediately, producing a postsynaptic potential.
- Metabotropic receptors; associated with signal proteins and G proteins,
more prevalent than ionotropic and efforts are slower, longer lasting, more
diffuse, more varied. Metabotropic receptor attached to portion of signal
protein outside neurone, G protein is attached to portion inside.
- Autoreceptors, neurotransmitter receptors located in presynaptic cell,
control neuropterans release by presynaptic axon. they regulate and
monitor amount of neurotransmitters ion the synapse, which is important in
maintaing proper bodily homeostasis and function. When neurotransmitter
has been released something needs to happen to prevent it from remaining
acive in synapse, bc accumulating ones could lead to danger and
problems, like too much dopamine in synapse can trigger delusions,
hallucinations, schizo signs.
- Reuptake, return of excess neurotransmitter into presynaptic axon, like a
- Degradation, neuropterans are broken apart within synapse by enzyme.
-thought to be supportive of neuron's functioning. 4 types;
oligodendrocytes; form myelin within central nervous system.
Schwann cels; form myelin in peripheral nervous system. A
strocytesl largest glial cells, functions like passage of chemicals from
blood into CNS.
Microglia; work by removing cellular debris inc axes of injury or
CNS: Cortical Structures
- right hemisphere controls left side of body, and vice versa.
- brain inside skull for protection, and covered by laters of meninges.
- 4 layers: dura mater, arachnoid layer, subarachnoid space, (CSF
here, but its also in central canal of spinal cord and cerebral ventricles, and
pia mater; closest to brain.
- central canal goes from spin cord, central ventricles are 4 large closes in brain giving it characteristic butterﬂy shape on brain scan. two lateral
ventricles, third ventricle, and fourth, connected to one another, and to the
central canal and subarachnoid spaces.
- CSF produced by group of capillaries, called chorioid plexus, inside
ventricles. The excess CSF ﬂows from ventricles around superior sagittal
crest, and drains to blood ﬁlled space which run throughout dura mater,
then into large jugular veins of neck.
- blood-brain barrier, group of compacted cells so tightly bound together
they keep toxic substances out of brain. different from blood cells in other
parts of body which are not as tightly packed, do not form any kind of
potectie brier against foreign substances. it basically doesnt let protein and
large molecules into brain, but few exceptions like glucose and oxygen. sex
hormones are allowed passage in some areas tho.
- telencephalon has cerebral hemisphere and 4 divisions, termed brain
- cerebral cortex; convoluted surface later of fray matter of cerebrum,
controls coordination of sensory and motor information. Large furrows,
called ﬁssures, and small ones called sulci, and ridges between them are
gyro, they all give it appearance of a topographical map. largest gyro
include pre central gyrus, contains motor cortex, postcentra gyrus;
including somatosensory enter, and superior temporal gyrusl contains
- corpus callosum; band of neural ﬁvers that allows right and left
hemisphere of brain to communicate; early treatment of epilepsy was to
sever this area, stopping neural activity from one hemisphere to the other
and also stopping communication.
- two different cortical neurons; pyramidal, resemble pyramids, large
multiple, large dendrite
- stellate neurons; star shaped and short, either few or no axons present.
Lobes of the Brain
- frontal lobe; in front of brain, responsible for higher order cognitive
abilities, thinking, reasoning, planning, language. area that a separates us
from other animals.
- occipital lobes; most specialized in functioning; back of brain, opposite to
frontal, important for vision. Optic chiasma, some of the axons of optic nerve cross over to other side of brain, or decussate. the axons on the
nasal side are those that cross to opposite side of brain. Decussation
allows each eye to view part of both the right and left visual ﬁelds, which is
important in case of accident, that has loss of vision.
- temporal lobes; side of cortex near temples. involved with processing of
information through hearing, left process auditory info for speech,
Wernicke's area i here. Right process auditory info in form of tones, music.
- Parietal lobes, top of brain, association cortex. responsible for spatial
orientation, visual perception, speech, pain sensation. important with how
we interact with people, place things, etc. they integral info from all other
the sense, leas localized of four lobes.
Other Cortical Structures
- hippocampus; responsible for memory functions. in cortex, contains 3
layers. its more in limbic system; control motivated behaviours, feeding,
sexual behaviour. which is related to emotional behavioural structures here
are mamllary bodies, amygdala, fornix, cingulate cortex, septum, in addition
t hippocampus. maxillary bodies, relay centre for info going to amydala and
hippocampus, and areas most affected by alcohol use, connected with
- amygdala carries signals from hippo to mamillar bodies, implicated in
- fornix C shaped bundle of axons in brain, carries signals from hippo to
- cingular cortex regulates blood pressure, heart rate, rational cognitive
- septum, thin membrane forms medial wall of lateral ventricle, aka septum
- basal ganglia; contained within telencephalon, include amygdala, caudate
nucleus, putamen, globes, pallid us. functions in voluntary motor behaviour.
amygdala is her took, its very active in moments that minds need to
differentiate emotional response.
- caudate nucleus, partially responsible for body movement and
- putament reinforcement earning
- global pallid us, relays info from other nuclei to thalamus; major relay
station for sensory info, all senses except smell, send info through here.
once its her, goes to appropriate areas of cortex. - hypothalamus; regulates release of hormones by pituitary gland, regulates
temperature within body, ﬂuid intake. and secual behaviour and foooood.
- pituitary gland; releases hormones that stimulate other parts of body.
-midbrain has 2 divisons
- tectum on topmost of mesencephalon, contains inferior colliculi,
function with auditory info and superior colliculi, visual function.
- tegmentum; contains reticular activating system; set of structures that
are related to arousal and alertness.
- also has periaqueductal brat, pain reducing effects of certain drugs,
- substantial nigra; laye of large pigmented nerve cells, proceed
dopamine and whose destruction associated with parkinson' disease.
- red nucleus, large well deﬁned, elongated cell mass, receive
projection from contrlateral alf of cerebellum, receives additional projections
from ipsilateraal motor cortex.
- met encephalon; ascending and descending facts, parts of reticular
- pons; estructure that relays info from cerebellum to cerebral cortex.
control sleeping, autonomic functions
- cerebellum; back of brain, involved with movement, coordination,
posture, often referred as "little brain:
- my encephalon; medulla, connected to spinal cord. composed of tracts
ascending/descening from brain. nuclei here regulate respiration and
- located outside of brain and the spinal cord, two divisions.
- somatic nervous system; peripheral nerves that send sensory info to
central nervous ystem and motor nerves that project to skeletal muscle.
composed of afferent nerves, that carry info from eyes, skin, ears to CNS
from senses. and also contains efferent nerves, carry motor signals aaay
- autonomic nervous system; regulates body's internal environment, part of
- contains efferent neurone that carry motor signals from CNS to
internal organs. there are 2 types of these nerves. sympathetic nerves, do
the ﬂight or ﬁght. has ffect opposite of parasympathetic nerves or nervous
system. parasympathetic nerves, one of two systems within ANS, calming
and opposite of SNS. associated with state of relaxation and secual arousal.
-resides in central canal, ﬁlled with CSF
-made of 2 areas dilenated by inner H shaped core of bray matter,
surrounding area of white matter. the tray matter, composed of cell
nobodies, unmyelinated interneurons, white, composed of myelinated
areas, give wjhite colour. dorsal horns at fray; ventral at ventral gray.
- axons joined to spinal cord bia dorsal or ventral root. dorsal root axons
sensory afferent, cell bodies group together outside cord to form dorsal root
ganglia. bring sensory info to spinal cord or brain.
- ventral, motor, efferent neurons, extend axons outside of CNS, directly
indirectly control muscles.
CHAPTER 3: NEURODEGENERATIVE DISORDERS
- neurodegenerative disorders- involve progressive loss of function or
destruction of neurone or various structures of the brain. they can be
acquired disorders, which are caused by an accident, insult, or disease
process coming from source outside the cortex. it's important to understand
clinically presented symptoms bc dissimilar difﬁculties present themselves
with similar symptomology, like distinction between dementia and
depression, as bot present sadness.in many cases, loss of neurones is not
repairable, and loss of abilities is permanent.
- damage within cerebral cortex, leads to symptoms of dementia. damage
includes memory, reasoning, ability to abstract thought,
- 3 stages that fall into dementia:
- behaviours that may deviate from norm for individual, like small
changes in personality or memory lapses noticed by others.
- individual notices memory problems, tries to conceal them from
others, confabulation occurs, and they become lost/wander. Sundowning,
worsening of symptoms as day progresses, happens here.
- serious cognitive deterioration, in a edition to problems associated
with self care, at this point working with physicians. patients can't dress,
toilet, or feed themselves, but symptoms vary.
- most frequent cause of death for patients with dementia is pneumonia. Alzheimer's Type Dementia
- characterized by neuroﬁbrillary tangles and amyloid plaques, diagnosis
cannot be made until autopsy but is termed Alzheimer's type based on
behavioural symptoms. Tangles are made from tau protein; (protein that
researchers believe result from abnormal phhosphorylatin;) tangles of
dead tissue in brain. amyloid plaques are deposits of aluminum silicate and
amyloid peptides that cause loss of neurone and vascular damage. plaques
and tangles appear in normal people and in other degenerative diseases,
but in alzheimers there's a lot and a speciﬁc area they al gravitate towards.
- another common feature is loss of neurone in temporal area, leading to
changes in anatomical structures
- having ﬁrst degree relative with it, doubles our changes of acquiring it.
- 3 other risk factors:
- gene for protein apolipoprotein E (Apo E) on chromosome 19, helps
carry phopholipids and cholesterol within body. it has 3 types, E4 allele,
linked with Alzheimers.
- Down syndrome; most frequent cause of mental retardation, caused
by trisomy on chromosome 21.
- traumatic braina injury is a suspected cause, but its only if its very serious,
may result to it. another theory s that menopause women can get it due to
low estrogen, but that relates with educational level and SES, bc more
educated ones will consult medical advise of symptoms.
- most distinguishing cognitive features are severe verbal memory
difﬁculties, all stages of memory; endogeny, storage, and
retrieval.beginning in ﬁrst stage.
- treatment can be drinking ed wine, which contains antioxidants with
protective effect. there also meds that stop development of amyloid
plaques, and that keep tau in normal form. treatment for cognitive deﬁticits
usually with anti cholinesterase inhibitors, enhance cholinergic