Transcript chapter2

PSY 312: Brain and Behavior
Dr. Mark Prendergast
Office: B449 BBSRB (on the corner of
Virginia and Limestone St.)
Office hours: by appointment
Telephone: 257-6120
e-mail: [email protected]
Tracy Butler, M.S.
Office: 448-D BBSRB
Office hours: by appointment
Telephone: 323-0575
e-mail: [email protected]
Required Text: Basics of Biopsychology by
John P.J. Pinel (2007)
Outline: This class provides an introduction to structural and functional
characteristics of the nervous system. Topics range from simple brain structures
and behaviors to more complex functions such as drug addiction and other
psychiatric illnesses.
Attendance: Attendance is never a course requirement in my classes.
Cheating: Cheating is not tolerated. I define cheating as either giving or
receiving help during exams or during the writing of a paper. This can be from a
classmate or any other method, including copying from a WWW site. In addition,
any written assignment for this class is to be done independently and working on
written assignments together also constitutes as cheating. If you need further
clarification of what the University defines as cheating, please read the
description in your Students Rights and Responsibilities Handbook.
Anyone
caught cheating will at minimum receive a zero and likely fail the course.
Grading: Your grade will be based on the % correct on 3 exams, including the final
(100 points each, a total of 300 points). Each exam will consist of multiple choice
questions. If an emergency arises and you must miss class on an exam day, please
let me know prior to class. Make-up exams should be scheduled as soon as
possible. Final grades will be assigned on a curve based upon overall exam
performance. Regardless of class performance, however, 90% is guaranteed an "A",
80% at least a "B", 70% at least a “C”, 60% at least a “D” and below 60% an E.
Extra Credit: All students will be allowed to complete 1 extra credit assignment
worth up to the equivalent of 5 points on an exam. This assignment must be a 2
page (double spaced) summary of an article published in a scientific journal identified
on www.pubmed.com. Extra credit assignments are due prior to the final exam.
Documented disability policy: if a disability exists and requires academic
accommodations, please see me as soon as possible. To receive accommodations in
the course, you must provide me with a Letter of Accommodation from the Disability
Resource Center.
Anatomy of Brain
Sept. 9th and 14th:
Prendergast
NO CLASS
Neural Activity
Prendergast
Development of the Nervous System
Prendergast
Brain Damage and Neuroplasticity
Prendergast
Learning, Memory, and Amnesia
Butler/Prendergast
Hunger, Eating, and Health
Butler
Hormones and Sex
Prendergast
Sleep, Dreaming, and Circadian Rhythms
Prendergast
Addiction, Emotion, and Stress
Prendergast
Guest Lecture,
Dr. Bill Stoops: Studying Drug Abuse in Humans
Addiction, Emotion, and Stress, cont’d
Prendergast
Mechanisms of Perception
Prendergast
Behavioral Neuroscience of Psychiatric
Butler
Sensory Motor Systems
Prendergast
Special role that genes and heritability play in behavior
Prendergast
FINAL EXAM:
12/14 @ 1:00 p.m.
Lecture notes: available on-line before every class at
http://www.uky.edu/~prender/welcome_files/slide0001.htm
- hates Safari or Mozilla
- likes Internet Explorer
How should you use your textbook ???
1. Lecture material is the most important to know
2. The textbook is meant to help explain the lectures
3. If material is in the book but not the lecture, you will not be tested over it
4. You do not need to read every part of every chapter
I suggest…
1. … that you read lecture notes first, then consult the book
2. If there is still any confusion, come talk to me or Tracy
http://www.uky.edu/~prender/welcome_files/slide0001.htm
here is how you can print the slides out without the dark background, in plain black
and white.
1. click on print, when the print dialog box opens look to the lower left, for the menu
called "print what".
2. use the mouse to select "handouts"
3. just below that menu is another menu called "Color/grayscale". Use the mouse
to select "pure black and white".
4. just to the right of the "print what" and "Color/grayscale" drop down menus is a
menu called "slides per page".
Just pick how many slides you want per page and print them out. The slides will be
all black and white with no background.
Anatomy of the Brain
(and spinal cord)
What you see is NOT what you get !
Legend for color coding:
Cerebral cortex
Ventricle (cerebrospinal fluid)
Corpus callosum
Cerebellum
Brain stem
Gyri (gyryus): folds of brain
Sulci (sulcus): gaps between gyri
The HOPES Brain Tutorial (Stanford University)
2 primary cell types in
nervous system
1. neurons – 10 to 100 billion neurons
can vary tremendously in size and shape but all have 3
components
• Cell body or “soma”
– contains nucleus
• Dendrites
– “antenna” of neuron, projections that receive chemical signals
from other neurons and other types of cells
• Axons
– The “transmitter” of a neuron, it’s usually a long fiber (can be inches long)
that ends very closely to another neuron
goal of every cell is to receive chemical signals from nearby cells and
to send chemical signals to nearby cells
Dendrites
Cell Body
Axon
1
2
3
1. Chemicals are transported to end of axon
by “microtubes”
2. Packaged in fatty “sacs” called “synaptic vesicles”
3. Release, out of axon at the right time
Neurons can be:
Multipolar: many “processes” extend from
cell body (most neurons)
Unipolar:
1 process
Bipolar:
2 processes
1: “Nucleus”
* Core of cell body
* Contains almost all
genetic information
2: Nearby cells called
“oligodendrocytes”
wrap most axons with a
fatty substance called
“myelin”
3 primary types of neurons
• motor neurons
– efferent – carry info from CNS
• sensory neurons
– afferent – carry info toward CNS
• interneurons
– carry info within regions
2. Glial cells – 10 to 100X the number of neurons
• Glial cells provide important supportive role:
– providing nutrients to neurons
– provide support for neurons
• myelin sheaths (oligodendrocytes in brain/spinal cord
“Schwann cell in periphery)
– play a role in response to neuronal injury
• astrocytes
– play a role in brain development
• radial glia (helps guide new neurons to their place in brain)
2 divisions of the nervous system
• CNS – Central Nervous System
– brain, spinal cord
• PNS – Peripheral Nervous System
– Everything outside of the brain and spinal cord
PNS - peripheral nervous system
2 components
1. autonomic nervous system
- “involuntary”
- role in emotion and stress
– controls smooth muscles, cardiac muscles
and glands
– two anatomically separate components
Sympathetic Nervous System
(part of autonomic NS)
• “fight or flight”
– activated during emergencies, stress and/or
arousal
• ex. Adrenal gland releases adrenalin
(norepinephrine) into blood stream
• causes increased heart rate, better attention
You don’t need to remember
this stuff.
Parasympathetic nervous system
• Maintain homeostasis, energy restoration
– physiological changes:
– Role is to regulate normal bodily function at
times of rest
- lower heart rate, stimulates digestion of
food, controls urination, etc.
You don’t need to remember
this stuff.
2. Somatic nervous system
• voluntary nervous system
– 31 pairs of spinal nerves
– ** NERVE – BUNDLE OF AXONS OUTSIDE THE
CNS
– sensory nerves
• Afferent (transmit information about touch, pain,
temperature. (but not vision or smell !)
-Motor nerves
-Efferent (controls movement)
Spinal column and spinal nerves:
Bridge from brain
to peripheral NS
Sections of Cord
Cervical
Thoracic
Lumbar
Sacral
A pair of nerves (31 pairs) emerges from each level
1 of each pair = sensory info. to spinal cord from body
1 of each pair = motor info. from spinal cord to body
dorsal
ventral
Gray matter vs white matter ??
Dorsal root (incoming) vs ventral root (outgoing)
“afferent”
Brings info. INTO
the the brain
“efferent”
Sends info. OUT
of the brain
Brain-maps.com
Courtesy, Marie-Luise Lehmann
Central Nervous System
- brain and spinal cord
• How is it protected?
– skull
• obvious - advantages of skull
• less obvious - disadvantage- closed head injury
• -swelling causes compression of brain
CNS
• How is it protected?
– Skull
– CSF - cerebrospinal fluid
• CSF production
» role of ventricles
• Advantages:
» Cushion
» Delivers nutrients
• Disadvantages:
» hydrocephaly
CNS • How is it protected?
– Skull
– CSF - cerebrospinal fluid
– meninges
3 membranes that “wrap” around the outside of brain
dura mater – “tough mold”, leather-like outer meninge
arachnoid – middle layer
pia mater-
“little mold”, directly attached to brain
Dura mater
Arachnoid mater
The Pia mater is too thin to see
(also, it usually tears off when the Arachnoid
mater is removed)
meninges-
Protect brain by:
preventing it from touch skull
holding cerebrospinal fluid in
stabilizing blood supply to and from brain
CNS
• How is it protected?
– Skull
– CSF - cerebrospinal fluid
– meninges
– blood brain barrier
Blood-brain barrier (BBB):
protects brain by making it
difficult for substances to get in
•Most substances (nutrients, oxygen,drugs, proteins, etc.) are carried into the
cranium by the blood stream. But, most things can’t get from the blood
to neurons because of the BBB
capillaries
1.
Blood
2.
arteries
Drugs, oxygen, nutrients, etc.… diffuse through capillary walls into tissue
3.
organs
muscle
brain
Capillary
Red blood cells
muscle
organs, etc
muscle
organs, etc
muscle
organs, etc
Lipid (fat) cells
Capillary in
peripheral
nervous system
O2
drugs
nutrients
toxins
1. Things in blood diffuse into tissue relativelyEndothelial
easily cells
Capillary in
Central
Nervous System
O2
1. Most things can’t get out of capillaries because of endothelial cells
2. Important things, like oxygen, glucose are “transported” into brain
by special transporters
Example of the importance of blood-brain barrier
1. Medication dosing: some drugs (for example, Prozac, Paxil)
cross from capillaries to neurons easily.
* hijack “transporters”
* some can “slip” through without transporter
This means that you can give a low
dose (small amount) of the drug to get a
good response
But, if a drug doesn’t cross capillary membrane easily…?
You have to give a lot of the drug (high dose)
Much more likely to get nasty side effects
2. Brain Damage:
Many “types” or “classes” of drug have a very, very
hard time getting past the blood brain barrier
So, if you are trying to treat a disease that affects the
brain (as well as the rest of the body), the brain is
especially likely to be damaged by the disease
HIV/AIDS
Most of the drugs used to treat HIV infection and AIDS
don’t cross the blood-brain barrier easily
Exception to the blood-brain barrier:
1. Area of brain that has “chemoreceptors”
to detect toxins that get in blood stream
The “vomit center”
a.k.a. “Area postrema”
2. A gland in CNS that controls several hormones
Intro to Brain Development Terminology
5 divisions of brain during “embryologic” development (first 8 weeks)
1 = Telencephalon
2 = Diencephalon
3 = Mesencephalon
4 = Metencephalon
5 = Myelencephalon
72 hr old chick
http://www.mcatzone.com/glosslet.php?letter=t
Telencephalon (cerebral cortex, limbic system, basal ganglia): “thought”, emotion,
motor control
Diencephalon (thalamus and hypothalamus): sensory relay, homeostatic functions
Mesencephalon (midbrain): tectum (dorsal) and tegmentum (floor)
Metencephalon (pons and cerebellum): pons is fiber tracts, cerbellum is motor area
Myelencephalon (medulla): efferent and afferent fiber tracts, “reticular formation”
arousal, sleep, attention
The University of South Wales, Dr. Mark Hill
• 3 main divisions in a “fetus” (8 weeks to birth)
hindbrain
midbrain
forebrain
metencephalon
mesencephalon
telencephalon
myelencephalon
Back
or end
Evolutionarily: “Old”
diencephalon
middle
front
“younger”
“youngest”
“Older” part of brain are more similar to lower animals than “young” ones
a. Forebrain – also known as the “cerebrum”
Cerebral cortex
Much larger portion of the total brain weight than seen in almost all
other animals
- allows for more cognitive ability and emotional range
The Forebrain (telencephalon and diencephalon)
largest part of the brain. Makes up 2/3 of entire organ.
left and right cerebral hemispheres are separated by the longitudinal fissure
Outermost covering = the cerebral cortex - gray matter: cell bodies and dendrites of
neurons.
Telencephalon
1. Cerebral cortex (outer portion) has four lobes with the following functions:
Frontal - Primary motor cortex - Voluntary control of skeletal muscles;
controls personality, intelligence, emotional control and speech.
Temporal - Auditory cortex and olfactory cortex; Conscious perception of
auditory, olfactory stimuli.
Parietal - Primary sensory cortex; Conscious perception of touch, pressure,
vibration, pain, temperature, and taste - controls sensory input
Occipital - Visual cortex: Conscious control of visual stimuli.
frontal
parietal
occipital
temporal
Gyrus: raised ridge of
tissue
Sulcus: fissures or
folds
Fissure: large sulcus
3 major functions and areas of cerebral cortex:
Sensory -
motor -
associative
Sensory areas receive/interpret impulse for sense receptors:
eyes, ears, taste buds, nose, touch, pain, pressure, heat, and
cold receptors.
Motor areas of cortex start impulse responsible for all voluntary
movement.
Associative areas are responsible for memory, learning, and
thought. These areas combine information from lower areas
and make sense of it to make decisions.
The Telencephalon, cont’d
Just below the cortex lies several structures that are
very important for emotion, learning, movement, language
and other behaviors.
2. Limbic system: emotion and learning
3. Basal ganglia: movement
4. Corpus collosum: thick band of fibers that connects the
left and right hemispheres of the brain
Limbic system: large, interconnected network of nuclei
involved in emotion, learning, and sensory information
Basal Ganglia:
'basal ganglia' means: the caudate nucleus, putamen
and globus pallidus
importantfor controlling voluntary movements
and establishing postures
Putamen and
Globus pallidus
=
“lentiform nucleus”
Corpus collosum
The 2nd part of the forebrain is the “Diencephalon”
Comprised of several regions involved in:
- relaying sight, smell, sound, etc. info. to cortex
“thalamus”
-regulating temperature, thirst, sexual behavior, eating…
“hypothalamus”
- fibers tracts from eyes vision (optic chiasm)
- “Pituitary gland” = regulates many things using hormones
The Diencephalon sits right on top of the Midbrain
Forebrain summary
telencephalon
diencephalon
Cerebral cortex
thalamus
Limbic system
hypothalamus
Basal ganglia
pituitary gland
Corpus collosum
optic chiasm
b. Midbrain (mesencephalon) – sensory relay center (relays info.
from outside of brain to brain
In lower animals = is more dominant and important than in humans.
Midbrain
1. Just above pons.
2. Largest part of brain in lower
vertebrates.
3. Center for visual and auditory
reflexes: pupil reflex, blinking,
adjusting ear volume to sound
4. Neurons that influence basal
ganglia and movement are here
5. Neurons that influence pleasure
are here, project to limbic system
C. Hindbrain - (mylencephalon and metencephalon)
sensory/motor relay, movement, arousal, control of internal organs
cerebellum
Pons
medulla
Reticular formation
NOTE: the Brain stem is composed of the Midbrain and the Hindbrain
Pons
1. Serves as a relay system,
linking spinal cord, medulla
oblongata, cerebellum, and
cerebrum.
Cerebellum
1. motor learning
2. Motor reflexes
Medulla Oblongata
1. Lowest portion of brain.
2. Controls internal organs:
heart rate, peristalsis,
respiration, secretions from
glands, blood pressure,
swallowing, coughing, and
vomiting.
3. Connects spinal cord with
other parts of brain.
Reticular formation
1. wake/sleep cycles
2. attention
Hindbrain summary
metencephalon
myelencephalon
Cerebellum
medulla
Pons
reticular formation
Reticular formation
Cranial nerves primarily serve head and face
How to remember the cranial nerves…
On
Old
Olympus'
Towering
Top
A
Finn
And
German
Viewed
Some
Hops
Olfactory nerve,
Optic nerve,
Oculomotor nerve,
Trochlear nerve,
Trigeminal nerve,
Abducens nerve,
Facial nerve,
Auditory nerve,
Glossopharyngeal nerve,
Vagus nerve,
Spinal accessory nerve and
Hypoglossal nerve.