This document provides an agenda and notes for a lecture on neural and hormonal systems. The agenda includes discussing neurons, action potentials, and synaptic communication. The notes cover topics like the basic parts and functions of neurons, how neurons communicate via neurotransmitters and action potentials, examples of neurotransmitters and how drugs can affect them, divisions of the nervous system, and an introduction to the endocrine system and hormones. Interactive activities are included, such as having students put events of neural communication in chronological order and demonstrations of reflexes.
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NEUROSCIENCE AND
BEHAVIOR /
BIOLOGICAL BASES OF
Module 4 BEHAVIOR
*Biological Psychology
- concerned with the links
between biology and behavior
Warm Up Agenda
Get into 4 groups. Make a Y. Everyone except the
front and back persons are blind.
– Create a system of communication that does not involve
Module 4: Neural and Hormonal
verbal or visual communication among “survivors.” Systems
Touching is allowed.
– Neurons
Create a system of communication that does not
involve auditory or visual communication b t
i l dit i l i ti between – Action potentials
“islands.” Seeing people are mute and cannot – Synaptic communication
touch other seeing people. You cannot cross the
gap. Exit ticket
– One catch: only one person from each island can send
messages among islands and one person from each island
can receive the message.
The goal: Send the final message to the rest of the
group.
Fact or Falsehood Fact or Falsehood
1. A small amount of brain tissue from 1. Electrically stimulating a cat’s brain
a person cannot be distinguished at a certain point can cause the
from that of a monkey. animal to cower in terror in the
2.
2 The human brain produces its own presence of a small mouse
mouse.
natural opiates that elevate mood 2. Both animals and humans seem to
and ease pain. have reward centers located in the
3. The brain accounts for a larger brain.
percentage of body weight in 3. We ordinarily use only 10 percent of
humans than in any other species. our brains.
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Fact or Falsehood Phrenology
1. Some people can write but are Franz Gall
unable to read. Germany
2. If a blind person uses one finger to Early
read Braille, the brain area
Braille 1800 s
1800’s
dedicated to that finger expands. bumps =
mental
3. Adult humans cannot generate new abilities
brain cells. 37 traits
4. Some people have had the
hemispheres of their brains split
with no apparent ill effect.
HOW DOES THIS… LEAD TO THIS?
We are… We are…
Systems: A group of interacting, What is the smallest level of
interrelated, or interdependent analysis?
elements forming a complex whole.
Biological.
Bi l i l
Biological, Psychological, Social
We will examine how at this level
What is the smallest level of “we” take in information: organize,
analysis? interpret, and store it; and use it.
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Neuron = Nerve Cell Efferent Neuron = Motor Neuron
-processes and transmits information (innervates muscles or other organs)
Afferent Neuron = Sensory Neuron Interneuron =
(receives information from sense organs) (sends and receives information between neurons)
How do these nerve cells How to neurons communicate
exchange information? with each other?
Electrochemically. – Neurons are not physically joined
– Between neurons, a signal travels together.
chemically. – Therefore how do they pass a signal
– Within the neuron, a signal travels
neuron across a physical space known as a
p y p
“electrically” via the movement of ions. synapse.
The word "synapse" comes from Greek: "syn"
"syn"
meaning "together" and "haptein" meaning "to
"haptein"
clasp."
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How Neurons Communicate
Neurotransmitters (NT)
“You are your – Released from the axon terminal buds.
– Cross synapse.
y p
synapses.” – Connect to correct receptor-channels on
dendrites
receptor-
– Unlock channels at the receiving site allowing
Na+ ions into the receiving neuron.
neuron.
-Joseph Le Doux
How Neurons Communicate
Two Categories of Neurotransmitters (NT)
– Excitatory: allow positive Na+ ions allowed in
causes firing
– Inhibitory: allow negative ions allowed in
prevents firing
Examples:
– ACh (acetylcholine): excitatory NT
– GABA: inhibitory NT – keeps brain calmed
down and not firing out of control
DRUGS
Every drug that affects behavior
works at the synapse
– Agonist: excite the receiving neuron.
They are similar enough the NT that it
mimics its effects.
They block the reuptake of the NT in the
synapse
– Antagonist: inhibit the receiving neuron.
They can block receptor site, block release
of NT from sending neuron.
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Examples
Curare:
– Stops ACh from fitting into receptor
sites (used by natives on poison darts)
darts)
Botox aka Botulin
– Blocks the release of Ach from the
sending neurons (paralysis)
Black Widow venom:
– Is similar to Ach and activates receptor
sites (seizures and convulsions)
convulsions)
DRUGS cont. DRUGS cont.
Dopamine (NT): excessive levels in Endorphins: natural pain killing NT
the brain associated with – Toughens the membrane of
schizophrenia and low levels neurotransmitter sacs preventing them
associated with Parkinson s disease
Parkinson’s from breaking
o b ea g
Pain signal is stopped
– Thorazine
used for schizophrenia patients b/c it blocks – Morphine and other opiates: mimics
dopamine (antagonist) endorphins (agonist)
– L-Dopa used for Parkinsons (agonist)
Patients develop tolerance
Seratonin (NT) Questions
– Low levels associated with depression With so many NTs, are some found
– Administer prozac – prevents reuptake only in certain places?
(agonist)
– M.A.O.’s breakdown seratonin
M.A.O. s
How d they affect mood, memories,
H do th ff t d i
– S.S.R.I. (selective seratonin reuptake
inhibator)
and mental abilities?
M.A.O. inhibitors help seratonin (agonist)
Can we boost or diminish these effects
through drugs or diet?
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How do these nerve cells
Pathways
exchange information?
Certain pathway uses 1 or 2 NT’s and Electrochemically.
that NT has a particular effect on a – Between neurons, a signal travels
behavior and emotion. chemically.
– Within the neuron, a signal travels
neuron
“electrically.”
We are going to go backwards to see
the process.
Question: What makes the NTs
release from the axon terminals?
How do these nerve cells
exchange information?
Question 2: Where does this electric
message come from?
It’s the movement of ions (charged
particles) across the cell membrane
of the axon.
This movement is called an
action potential.
Neural Impulse or Action Potential
Worth Archive Video
Video Animation of an Action Potential
Another more detailed lesson
lesson.
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Neural Impulse or Action Potential Neural Impulse or Action Potential
Resting potential:
potential: Action potential:
– Ratio of – Positive Na atoms rush in and trigger a domino
2 Positively charged K+ atoms inside effect down the axon. The region inside
3 Positively charged Na+ atoms outside becomes slightly positively charged.
– Therefore, outside the neuron, it is
Therefore neuron In other words, the cell becomes
words
positively charged and depolarized.
– inside the neuron, it is negatively And guess what? It’s like dominoes.
charged (-70 mV)
(-
Once it starts, it can’t be stopped.
In other words, the neuron is – This is called the all-or-none principle.
all-or-
polarized.
Neural Impulse or Action Potential Question…
Refractory period: Question: What starts the action
– A period of time when the neuron must
become polarized again
potential down the axon?
– In other words… Demonstration perhaps?
– Positive Na atoms go back out
*Can happen 1000 times per second
This is our answer. Question…
Question: What starts the action
potential down the axon?
Demonstration perhaps?
Answer: The cell body and axon
A Th ll b d d
hillock are like a water gun, clown’s
mouth, and a balloon.
In other words, it’s an adding
machine.
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A Little (New) Order Keep these in mind…
1. Get into groups of 3 or 4 Depolarization
2. I will give you an envelope. All-or-
All-or-none principle
3. It contains events and ideas Direction of impulse
involving neural communication.
i l i l i ti Refractory period
4. Put them in the correct Threshold
chronological order. Resting potential
5. Some terms may or may not fit. Action potential
Level of Analysis Neural Chain (radio)
From the molecular and cellular level 1. Receptor Cells (antennae):
- Skin on fingers
2. Sensory cells (wires connected to radio)
Tissue - Send impulse to brain
Organs
O 3. Interneuron cells (radio)
- brain
Organ Systems
4. Motor cells (wires to speaker)
- Back down arm to hand
5. Effector cells (speaker)
- Control muscles that retract fingers
Reflexes caused by inter-neurons in Central Nervous System
the spinal cord (demos)
Neural Networks form from learning and
practice
– Increases the speed messages are sent
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http://www.youtube.com/watch?
v=DF04XPBj5uc You versus a computer
40 billion neurons
X
10,000 connections/neuron
=
400 trillion synaptic connections!!!
Level of Analysis Lou Gehrig
From the molecular and cellular level http://www.youtube.com/watch?v=a
4msaZTJrTA
Tissue
Organs
O
Organ Systems
DIVISIONS OF THE NERVOUS
Amyotrophic Lateral Sclerosis
SYSTEM
6 out of 100,000 people usually Central Nervous System
between ages 60 to 75 – brain and spinal cord
Death within 5 years – billions of neurons
Reason: D th of motor neurons.
R Death f t Peripheral N
P i h l Nervous S t
System
Possible causes: – Sensory and motor neurons that
connect the brain to the rest of the body
– Death of microtubules in those axons
– A few millions for each.
– Buildup of toxic chemicals within
neurons
– Toxic chemicals from other neurons
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DIVISIONS OF THE NERVOUS Peripheral Nervous System
SYSTEM (2 components)
NERVOUS SYSTEM Somatic Nervous System:
– voluntary control of skeletal muscles
Autonomic Nervous System:
PERIPHERAL CENTRAL – controls th glands and muscles of
t l the l d d l f
internal organs
Sympathetic nervous system arouses (3 F’s)
AUTONOMIC SOMATIC Parasympathetic nervous system calms
SYMPATHETIC PARASYMPATHETIC
Tell me what’s happening within
your nervous system.
Tell me what’s happening within
your nervous system.
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Neural Chain (radio) Reflexes
1. Receptor Cells (antennae):
- Skin on fingers
2. Sensory cells (wires connected to radio)
- Send impulse to brain
3. Interneuron cells (radio)
- brain
4. Motor cells (wires to speaker)
- Back down arm to hand
5. Effector cells (speaker)
- Control muscles that retract fingers
Reflexes Central Nervous System
http://www.youtube.com/watch?v=Q Neural Networks form from learning and
mNQdLkkJHM&NR=1 practice
– Increases the speed messages are sent
Class example
You versus a computer You are complex
40 billion neurons Neurons
X Reflex arcs
10,000 connections/neuron
10 000 ti / Networks
Pathways
=
Specialized regions
400 trillion synaptic
Brain Systems
connections!!!
The Brain
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Exit Question
On a strip of paper, What do you think has more lasting
effects?
–write down one question
you have from today’s
today s
lecture and
–drop it off in the black tray
by the door.
A text that reads “143” OR The Endocrine System
• Glands that
produce
hormones that
travel through
the body to
y
affect certain
tissues
• Pituitary gland
(master gland)
gland)
The Endocrine System
NT’s and hormones
are chemically
similar if not the
same.
Feedback System:
Brain
(Hypothalamus)
pituitary other
glands hormones
brain behavior
E.g.: puberty
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