Biopsychology

The Biological Basis of Behavior

Neurons: Structure

Dendrites Cell Body Axon Myelin Sheath Nodes of Ranvier Terminal Buttons

p. 45

Normally Functioning Nerves

The Synapse

Synaptic Vesicles Synaptic Cleft Receptor Sites Presynaptic membrane Postsynaptic membrane Neurotransmitters

p. 47

Neurotransmission

1. Resting Potential (-70 millivolts)

2. Threshold ( greater than -70 mv)

3. Action Potential ( positive)

4. Hyperpolerization (less than –70 mv)

5. Resting Potential (-70 mv)

Action Potential

-90

-70

-50

-30

-10

10

30

50

70

Time (ms)

Mem

bran

e Pot

entia

l (m

v)All or None Response

Threshold Graded Potential

HyperpolarizationResting Potential

Effects of Neurotransmitters

Excitatory

Inhibitory

Types of Neurotransmitters

Acetylcholine: ACh Norephinephrine: NE Dopamine: DA Serotonin: 5-HT Gamma-amino-butyric acid: GABA

Acetylcholine (ACh):

found through out the central nervous system, autonomic nervous system, and all neuromuscular junctions.

Excitatory Involved in muscle action, attention, learning, and

memory Too much: spasms Too little: paralysis

Norephinephrine: NE

o Synonymous with Adrenalino Found in ANSo Excitatoryo Responsible for getting “pumped up”

• Fight or Flight Response

o Eating behavior• Carbo-craving

Dopamine: DA

Reward system Produced by neurons located in a region of the brain

called the substantia nigra. Involved in pleasure, movement, attention, and

learning. Degeneration of dopamine-producing neurons has

been linked with Parkinson’s Disease. Too much dopamine is implicated in schizophrenia and Tourette’s .

Serotonin: 5-HT

Found in the brain and spinal cord. Inhibitory Plays a role in the regulation of mood and is control

of eating, sleep and arousal. Has also been implicated in the regulation of pain and dreaming.

Destroyed by MAO SSRI’s (Prozac, Zoloft)

Gamma-amino-butyric acid: GABA

Found through out the brain and spinal cord, in very high concentrations compared to other Neurotransmitters.

Inhibitory Is the major inhibitory neurotransmitter in the brain.

Abnormal levels of GABA have been linked to eating and sleeping disorders.

Nervous System

CentralBrain & Spinal Cord

PeripheralSomatic

???

AutonomicParasympathetic

Sympathetic

N.S.

Peripheral Central

Somatic Autonomic

Sympathetic ParaSymp

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Autonomic Nervous System

Sympathetic Fight or Flight

Parasympathetic Maintenance & Refuel

1. Eyes open Wide

2. Mouth Goes Dry

3. Hr Increase

4. Start to Sweat

1. Eyes constrict

2. Mouth Waters

3. Digestion

4. Blood away from muscles

The Endocrine System The Brain Stem

What is the difference between a neurotransmitter and a hormone?

Where are the seats of consciousness?

Motivation & Emotion in the Brain

Hypothalamus

Limbic System

Thalamus

Cortex

o Parietal Lobe

o Temporal Lobe

o Occipital Lobe

o Frontal Lobe

Brain Lateralization

Left Hemisphere Right side of the body Language

Wernike & Broca

Right Hemisphere Left side of the body Creativity Math & Spatial tasks Nonverbal - Emotion

Q: What is the cause of ambidexterity?

A: Handedness (the preference to use one hand over the other) is species-specific. In humans, about 90% prefer to use their right hand. What does this mean? Recall that the human brain is divided into a right and a left hemisphere. Typically, the left hemisphere in humans is dominant. We're not really sure why the left rather than the right (or both) becomes dominant, but probably it reflects the early fetal environment, particularly hormonal factors. Since the left hemisphere controls the right side of the body, people with left hemisphere dominance will be right-handed. For left-handers and for those who are ambidextrous (can use both hands with the same level of skill), the right hemisphere tends to be dominant. Interestingly, language, which typically is the province of the dominant hemisphere, is equally likely to reside in either the left or right hemisphere for non-right-handed people. Those who are left-handed or ambidextrous also tend to have a thicker corpus callosum (the bundle of fibers joining the two hemispheres).

Genetics

Structure and Function

Gene therapy

Nature vs. Nurture