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2 The Brain and Behavior
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Nervous System
Neurons
Brain
Endocrine
System
Brain Damage, Plasticity,
& Repair
Genetics
&
Behavior
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Nervous System
Complexity
Integration
Adaptability (plasticity)
Electrochemical transmission
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Nervous System: Pathways
afferent
efferent
Which type connects with skin?
With muscle?
Nerves carry information
Body
Brain
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Caution: Both types of nerves connect with muscle.
Note: Instructor may delete discussion question, or may add analogous questions about bone joints and internal organs
Nervous System: Divisions Nervous Systems (NS)
Central (CNS)
brain and spinal cord
Peripheral (PNS)
Somatic NS
sensory nerves
motor nerves
Autonomic NS
sympathetic NS
parasympathetic NS
muscular activity
internal organs
arouses
calms
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5
Neural Impulse
Negatively + Positively Charged Ions
Polarization (Imbalance in Charges)
Resting Potential
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Neural Impulse
Semipermeable Membrane
Ion Channels
Depolarizaton (Ion channels open)
Threshold
Action Potential (Ion exchange sweeps
along length of axon)
All-or-None Principle
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Synapses and Neurotransmitters
Synapse
Vesicle
Neurotransmitters
Synaptic Gap
Receptor Site
Synaptic Transmission
Electrical impulse is converted into a chemical signal.
Axon vesicle releases neurotransmitter into gap.
Dendrite receptor site detects neurotransmitter
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Neurotransmitters
Neurotransmitters carry information across the synaptic gap to the next neuron.
Acetylcholine
muscle actions, learning, memory
black widow venom ↑ Ach levels
Botox (botulin) ↓ Ach levels
Alzheimer’s disease: ↓ Ach levels
GABA
Anxiety: ↓ GABA levels
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Centers for Disease Control
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Neurotransmitters
Glutamate
excitatory
learning and memory
involved in many psychological disorders
Norepinephrine
stress and mania: ↑ norepinephrine levels
depression: ↓ norepinephrine levels
regulates sleep states in conjunction with Ach
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Neurotransmitters
Dopamine
voluntary movement
reward anticipation
stimulant drugs: activate dopamine receptors
parkinson’s disease: ↓ dopamine levels
schizophrenia: ↑ dopamine levels
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Neurotransmitters
Serotonin
regulation of sleep, mood, attention, learning
depression: ↓ serotonin levels
Prozac: ↑ serotonin levels
Endorphins
natural opiates
mediate feelings of pleasure and pain
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Neurotransmitters
Oxytocin
both a hormone and a neurotransmitter
related to onset of lactation in new mothers
related to attachment/emotional bonds
Note: Drugs can interfere with neurotransmitters.
mimic or enhance NT effects
block effects of NT
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Neural Networks
Interconnected pathways of nerve cells
Integrate sensory input
and motor output
Where a given piece of information is stored:
not in a lone neuron or connection
but spread over multiple connections and neurons
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