LECTURE 02

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Published on 18 Sep 2012
School
University of Waterloo
Department
Psychology
Course
PSYCH101
Professor
Page:
of 10
LECTURE 02 BEHAVIOURAL NEUROSCIENCE I
THE NERVOUS SYSTEM AND THE BRAIN THE BIG PICTURE
- Neuron
o The basic cells that make up the nervous system
- Peripheral Nervous System
o All the other nerves that run through the body which are not the
brain or the spinal cord
- The Central Nervous System and the Brain
o One of the frontiers that we understand the least of in psychology
- The Endocrine System
o Hormones
o The different chemicals that float through the blood and also
influence us
- Putting it all together The Example of Hunger
o Not completely separate systems all work together and influence
each other
o Example of hunger to see how all these systems work together
THE NEURON
- Myelin Sheath
o Globular part of the neuron which are not found in the neurons of
the brain
o Let the electric current bounce from node to node, so that the
impulse can travel quickly (when touching a hot stove, you can put
your hand back real quick)
o Neurons which are part of the Peripheral System and part of the
spinal cord, actually work faster than our brain (allow quick
reactions due to the electric pulse can‟t get to jump or skip)
o Dendrites
At the back end of the neuron
Back end = left; Front end = right; Neural Impulse (in
between Myelin Sheath among Myelin Sheath)
Neural Impulse - electricity that moves around neurons (the
uniqueness of neurons = conducting electricity)
Neural Impulse moves from Dendrites to Axons
Axon (Terminal branches of the Axon) = front end (where the
neuron travels to)
Neural Impulse and Myelin Sheath are also part of
Axon
o Cell Body
The cell‟s life-support centre
o How do you take a piece of tissue, like a cell or a neuron, and have
it conduct electricity?
Study of Sea Slugs
o How impulses travel down the Neuron
Chemical reactions (not much difference than in batteries, in
some sense)
Direction of neural impulse toward axon terminals: Cell
body end of axon Positive ions
Movement of ions in and out of the cell membrane is what
creates the electricity and causes it to flow down the neuron
o Synapse
Sending neuron Synapse (the sending neuron touches
the receiving neuron)
Synaptic Gap: the whole place that they „touch‟ each other
How Neurons come together and talk to each other
o Sending neuron Action Potential (Myelin Sheath; Axon)
Vesicle containing neurotransmitters Axon terminal Synaptic
gap Neurotransmitters Receptor sites on receiving neuron
o It‟s a very complex combination of a whole bunch of synapses
coming together at once to determine whether the next one fires.
o Reuptake
NEUROTRANSMITTERS
- Dopamine
o Very common especially in the brain
o Disorders
Parkinson‟s Disease
Part of the cause is a deficiency of dopamine (shake
in hands)
Marked by tremors
Very important in the coordination of movement
Also important in attention and emotion
Schizophrenia
Marked by an excess of dopamine in various parts of
the brain
- Serotonin (new anti-depressants)
o Involved in mood, hunger, sleep and arousal
o It affects things widely in the brain
o A deficiency of serotonin is a cause of insomnia
o Deficiencies are also associated with depression
- Norepinephrine (old anti-depressants)
o More related to alertness and arousal (loss in hunger and sleep)
o Also associated with depression
- Acetylcholine
o The most common neurotransmitter
o Involved in muscle movement
o Alzheimer‟s Disease (too much or too little)
The neurons that work through acetylcholine get ruined with
Alzheimer‟s
o Also involved in learning and memory (particularly short-term
memory)
- Endorphins
o Involved in pain regulation
When injured, the body naturally releases these endorphins
which allow you to handle a lot more pain
o Heroine and morphine mimic this neurotransmitter (to reduce pain)
HOW DRUGS AFFECT NEUROTRANSMITTERS
- Agonist mimics neurotransmitter: trigs the cell that would be receiving the
neurotransmitter and thinking it‟s an external neurotransmitter (not exactly
the same thing but it fits in the synaptic gap and trigs and make it think it‟s
the same thing that‟s gonna happen)
- Antagonist blocks neurotransmitter (doesn‟t change the cell membrane but
makes the real neurotransmitter to change the cell membrane it‟s like a
blocker, it gets in the way that prevents neurotransmitter from affecting the
entrance of a cell)
- Two ways for drugs to work
o 1. By acting just like the neurotransmitter, and in effect making it
think that there is more of it; good if there is a deficiency
o 2. Others act like blockers and keep the neurotransmitter from
having as much of an effect; good if there is too much of a
neurotransmitter

Document Summary

The nervous system and the brain the big picture. Neuron: the basic cells that make up the nervous system. Peripheral nervous system: all the other nerves that run through the body which are not the brain or the spinal cord. The central nervous system and the brain: one of the frontiers that we understand the least of in psychology. The endocrine system: hormones, the different chemicals that float through the blood and also influence us. Putting it all together the example of hunger: not completely separate systems all work together and influence each other, example of hunger to see how all these systems work together. At the back end of the neuron. Back end = left; front end = right; neural impulse (in between myelin sheath among myelin sheath) Neural impulse - electricity that moves around neurons (the uniqueness of neurons = conducting electricity) Neural impulse moves from dendrites to axons.