Download Neurotransmitters - Lillian McMaster

Chapter 2
Biopsychology
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Copyright © Allyn and Bacon 2009
What is Biopsychology?
The specialty in psychology that studies
the interaction of biology, behavior, and
mental processes
For example this chapter looks at the
brain, nervous system, endocrine
system, and neurotransmitters and how
they impact behavior.
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What is neuroscience?
Focuses on how the brain produces mental
processes and behavior
Interdisciplinary field-includes specialists from all
the fields below
• psychologists
• biologists
• computer scientists
• chemists
• neurologists
• linguists
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How Are Genes and
Behavior Linked?
Evolution has fundamentally
shaped psychological
processes because it favors
genetic variations that
produce adaptive behavior
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Darwin and Natural Selection
Darwin – 1831
• 5 years surveying the coastline of South America
• Radical idea about relationship among species
• All creatures, including humans, share a common
ancestry
• On the Origin of Species (1859)
Natural selection –
Individuals best adapted to the environment are more
likely to flourish and reproduce
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How Natural Selection Works
Environmental pressure
(changes in the environment)
Competition
(for resources)
Selection of fittest phenotype
(from among a variety of phenotypes)
Reproductive success
(genotype corresponding to fittest
phenotypes passed to next generation)
Frequency of that genotype increases
(in next generation)
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Genes and Inheritance
Genotype –
An organism’s genetic makeup
Phenotype –
An organism’s observable physical
characteristics
Important Question- If both of your
parents have high blood pressure does
that mean you will have high blood
pressure?
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Chromosomes, Genes, and DNA
DNA –
A long, complex molecule that encodes
genetic characteristics
Genes –
The functional units of a chromosome
Composed of nucleotides
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Chromosomes, Genes, and DNA
Chromosomes –
Tightly coiled threadlike structures along
which the genes are organized
Sex chromosomes –
The X and Y chromosomes that
determine our physical sex characteristics
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Genetic Explanations for Psychological
Processes
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Human phobias
Aggression
Jealousy
Sexual orientation
Physical attraction
Mate selection
Parenting
Temperament
Gender differences
-Never attribute psychological characteristics to genetics alone:
always a combination of genes and environment
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How Does the Body
Communicate Internally?
The brain coordinates the
body’s two communication
systems, the nervous system
and the endocrine system,
which uses chemical
processes to communicate
with targets throughout the
body
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The Body’s Dual Communication System
Neurons (Nerve cells): fundamental
unit in the brain
Nervous system: network of neurons
that extends all through the body
Endocrine system: a group of glands
that operates together and in parallel
with the nervous system
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The Neuron
Types of Neurons
Sensory neurons (carry messages from
sense receptors towards the CNS)
Motor neurons (carry messages from
CNS toward muscles and glands)
Interneurons (carry messages
between nerve cells)
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The Structure of a Neuron
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The Neural Impulse
Resting potential
Action potential
Synapse
Synaptic transmission
All-or-none principal
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Neurotransmitters
Neurotransmitters –
Chemical messengers that relay neural
messages across the synapse to the next
neuron
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Seven Important Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Glutamine
Endorphins
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Glutamine
Endorphins
Normal Function:
Produces sensations of
pleasure and reward; used
by CNS neurons in
voluntary movement
Problems with Imbalance:
Schizophrenia, Parkinson’s
disease-why we watch
“Awakenings”
Substances that Affect:
Cocaine, amphetamines,
Ritalin, alcohol
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Neurotransmitters
Dopamine
Serotonin
Normal Function:
Regulates sleep and
dreaming, mood, pain,
aggression, appetite and
sexual behavior
Norepinephrine
Problems with Imbalance:
Acetylcholine
Depression, certain anxiety
disorders, obsessivecompulsive disorder
GABA
Glutamine
Endorphins
Substances that Affect:
Prozac, hallucinogenics
(e.g. LSD)
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Controls heart rate, sleep,
sexual responsiveness,
stress, vigilance and
appetite
Problems with Imbalance:
Acetylcholine
GABA
Glutamine
Endorphins
High blood pressure,
depression
Substances that Affect:
Tricyclic antidepressants,
beta blockers
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Acetylcholine
GABA
Glutamine
Endorphins
Normal Function:
Primary transmitter used by
neurons carrying messages
from CNS; involved in
some kinds of learning and
memory
Problems with Imbalance:
Certain muscular disorders,
Alzheimer’s disease
Substances that Affect:
Nicotine, botulism toxin,
curare, atropine
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Neurotransmitters
Dopamine
Serotonin
Norepinephrine
Normal Function:
Most prevalent inhibitory
neurotransmitter in neurons
of CNS
Problems with Imbalance:
Acetylcholine
Anxiety, epilepsy
GABA
Substances that Affect:
Glutamine
Endorphins
Barbiturates, tranquilizers
(e.g. Valium, Librium),
alcohol
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Copyright © Allyn and Bacon 2009
Neurotransmitters
Dopamine
Normal Function:
Norepinephrine
Primary excitatory
neurotransmitter in CNS;
involved in learning and
memory
Acetylcholine
Problems with Imbalance:
Serotonin
GABA
Glutamine
Brain damage after stroke
Substances that Affect:
PCP (“angel dust”)
Endorphins
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Copyright © Allyn and Bacon 2009
Neurotransmitters
Dopamine
Normal Function:
Serotonin
Pleasurable sensations and
control of pain
Norepinephrine
Problems with Imbalance:
Acetylcholine
Lowered levels resulting
from opiate addiction
GABA
Glutamine
Endorphins
Substances that Affect:
Opiates: opium, heroin,
morphine, methadone
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Plasticity
Plasticity –
Ability of the nervous system to adapt or
change as the result of experience;
sometimes helps the nervous system
adapt to physical damage
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Glial Cells
Glial cells
• Provide structural support for neurons
• Help in forming new synapses
• Form myelin sheath
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The Organization of the
Nervous System
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The Endocrine System
(the body’s chemical messenger system)
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The Endocrine System
Pituitary gland –
• master gland that produces
hormones influencing the secretions
of all other endocrine glands
• produces hormone that influences
growth
• attached to hypothalamus
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How Does the Brain
Produce Behavior and
Mental Processes?
The brain is composed of
many specialized modules
that work together to create
mind and behavior
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Windows on the Brain
EEG (electroencephalograph) –
Device for recording brain waves,
typically by electrodes placed on the
scalp
Brain waves –
Patterns of electrical activity generated
by the brain
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Windows on the Brain
Epilepsy –
• Brain disorder that is often marked by
seizures and loss of consciousness
• Caused by out-of-control electrical
activity in the brain
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Windows on the Brain
Brain scans –
Recordings of the brain’s electrical or
biochemical activity at specific sites
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CT scanning (computerized tomography)
PET scanning (positron emission tomography)
MRI (magnetic resonance imaging)
fMRI (functional magnetic resonance imaging)
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Three Layers of the Brain
Brain stem and cerebellum
• Drive vital functions, such as heart rate,
breathing, digestion
Limbic system
• Adds emotions, complex motives, increased
memory abilities
Cerebrum
• Enables reasoning, planning, creating,
problem solving
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The Brain Stem and Cerebellum
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The Limbic System
Hippocampus –
Involved in establishing
long-term memories
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The Limbic System
Amygdala –
Involved in
memory and
emotion,
particularly fear
and aggression
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The Limbic System
Hypothalamus –
Serves as the
brain’s bloodtesting
laboratory,
constantly
monitors blood to
determine the
condition of the
body
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Copyright © Allyn and Bacon 2009
The Cerebrum
Cerebrum –
Topmost layer of the brain; the
bulbous cap over the limbic system
Cerebral cortex –
Thin gray-matter covering of the
cerebrum; carries on thinking and
perceiving
Cerebral hemispheres –
The two walnut shaped halves of the
cerebrum, connected by the corpus
callosum
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The Four Lobes of the
Cerebral Cortex
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The Cooperative Brain
Every mental and behavioral process
involves the coordination and
cooperation of many brain networks
Association cortex –
Cortical regions that combine information
from various other parts of the brain
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Cerebral Dominance
Cerebral dominance
• Tendency of each brain hemisphere to
exert control over different functions
Aphasia
• The loss of speech caused be brain
damage
Spatial orientation
• Process of locating one’s body or other
objects in space
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Specialization of the
Cerebral Hemispheres
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The Split Brain
Split-brain patients –
Individuals who have had the corpus
callosum surgically severed
Duality of consciousness –
Condition in which a split-brain patient
has a separate consciousness in each
hemisphere
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Figure 2.2
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