Download File

AGONISTS
E FFECTS
•
•
•
•
ANTAGONISTS
OF DRUGS ON
N.S.
• Block actions of
Mimic actions of
neurotransmitters
neurotransmitters
 Occupy receptor site &
Bind to receptors &
prevent action.
generate PSP’s
 A molecule, that by binding
A molecule that, by
to a receptor site, inhibits or
binding to a receptor
blocks a response
site, stimulates a
 Botulin (poison found in
response
improperly canned food causes
Opiate drugs can
paralysis by blocking ACh
release
produce a temporary
 We call it Botox and inject it into
“high”
our faces to paralyze underlying
facial muscles 
BIOLOGICAL
PSYCHOLOGY AND
NEUROTRANSMISSION
WHY STUDY BIOLOGY IF THIS CLASS IS
CALLED PSYCHOLOGY??
 Everything psychological is simultaneously biological.
 To think, feel or act without a body would be like running without legs.
-We are bio-psycho-social systems. To understand our behavior, we
need to study how biological, psychological and social systems interact.
 The human brain is the most complex system, natural or man
made, in the world.
 About 3 lbs.
About the size of a grapefruit
Pinkish/gray in color
About 100 billion nerve cells
At a loss rate of 200,000 per day during our adult lives we still end up
with over 98% of or brain cells.
 Biopsychology: The specialty in psychology that studies the
interaction of biology, behavior and mental processes.
-The mind thinking about the mind .
 some biological psychologists call themselves behavioral
neuroscientists, neuropsychologists, behavior geneticists,
physiological psychologists, or biopsychologists
 Neuroscience is a newer field of study in psychology focusing
on the brain and our behavior.
PHRENOLOGY
 Back in the olden days, we
believed many very stupid and
silly things about humans and
our minds (cough…hindsight
bias..)
 One of those things was
phrenology - the believed that
studying bumps on the skull
could reveal your mental
abilities and skills.
BIOLOGICAL PSYCHOLOGISTS
Today, we now rely on biological
psychologists (people who study the
links between biological [genetic, neural,
hormonal] and psychological processes)
NEURONS
NEURONS ARE SUPER COOL
 A specialized cell that receives information and transmits it
to other cells
 Individual nerve cells that receive, integrate, and transmit
information
 The basic elements of communication in the nervous system,
but only the majority communicate with other neurons.
 However, there are some exceptions
 Approx. 100 billion neurons make up the brain
 Millions of neurons are involved in producing a single thought
A “T YPICAL” NEURON
GLIA
 Cells found throughout the nervous system that provide
various types of support for neurons





Outnumber neurons 10-1, 50% of the brains volume
Nourish neurons
Remove waste products
Insulation
The heroes of the nervous system
THE CHARGE INSIDE THE NEURON IS
NEGATIVE
Resting potential
● The imbalanced electrical charge of the axon
in its inactive state (when the neuron is ready
to fire)
oThe inside of cell is negative relative to the outside of the
axon
POLARIZATION
DURING RESTING POTENTIAL the neuron is
polarized = opposites of each other.
inside of a neuron’s charge is all NEGATIVE
Outside of a neuron, the charge is POSITIVE
Negatives w/negatives, positives w/positives.
“Happy homeostasis” prefers to be this way.
NEURON AT REST
 Inside and outside the neuron are fluids containing
electrically charged atoms and molecules called “ions”
 Positively charged potassium and sodium and negatively
charged chloride ions flow back and forth across the cell
membrane, but do NOT cross at the same rate
 HIGHER CONCENTRATION of negatively charged ions inside the
cell------ resulting voltage/potential energy
 RESTING POTENTIAL- stable, negative charge when the cell is
inactive (-70 million volts)
How Does it Work?
Neurotransmission is
a fancy name for two or more
neurons communicating with
each other.
There are 4 neurons
communicating in the picture
to the right or you could say
that neurotransmission is
taking place
1
3
4
2
Neurons stay at rest with their
sodium ions on the outside of
the cell body (or soma)
and potassium ions on the inside.
Neurons are no longer at
rest when the
sodium ions on the outside
of the cell body rush in
and potassium ions on the
inside rush out.
The typical neuron receives hundreds of messages…some
of these messages are excitatory (saying “FIRE”) while
others are inhibitory (saying “DON’T FIRE”)
e
e
i
e
e e e
e
e
i
i
e
i
When there are more
excitatory than inhibitory
messages, the cell body
exceeds its threshold (level
of stimulation required to
trigger the impulses) and
creates an electric
impulse…
This is called ACTION
POTENTIAL
Action potential
An electrical impulse is caused
from the rushing in and out of the
ions (depolarization)
Most basic – electrical charge
that travels through the axon of
the neuron; the message that
travels through the axon of the
neuron.
At that moment, the charge
becomes less negative/even
positive, creating an action
potential
Action potential is the DEPOLARIZATION of
a NEURON
Depolarization occurs, when positive sodium
(Na+) ions enter the neuron, making it more
susceptible to fire an action potential.
Neuron no longer @ homeostasis—domino effect.
Once the electrical
impulse reaches
the terminal button
it triggers the
vesicles (containing
neurotransmitters),
to move toward the
bottom of the
terminal button.
REFRACTORY PERIODS
 After all this excitement, the channels in the cell membranes
will close up again (and this may take some time)
Refractory Period
After a neuron has fired an action potential it pauses for a short period to
recharge itself to fire again – at this time the inside potassium ions move
out of the cell & cannot fire
Like a toilet bowl..gotta wait for the water to fill up again.
 Imagine running a sprint. After you finish running, you will
need a period of time (ARP) to calm down before you will run
again.
 After you completely recover, you can run again, but you will
need some more intense motivation (RRP), because you don’t
really feel like sprinting again.
Other Action Potential Info…
This graph depicts the change, with
time, in the electrical charge across
a given point on the axon
membrane as an action potential
passes through that point.
To transmit the “message”
the length of the axon takes
less than one hundredth of a
second!!
With each action potential, a small amount of sodium enters the
cell and a small amount of potassium leaves it – to maintain the
original balance of these elements, each portion of the axon has a
sodium-potassium pump that continuously moves sodium out of
the cell and potassium into it
http://highered.mheducation.com/sites/0072943696/student_view0/chapter8/animation__transmission_acr
oss_a_synapse.html
Synapse -- a junction
between the axon tip
of the sending neuron
and the dendrite or
cell body of the
receiving neuron. This
tiny gap is called the
synaptic gap or cleft.
Axon Terminal buttons
creates
NEUROTRANSMITTERS. Go
into gap, and received (from
receptor sites) on dendrites.
Create electrical impulse
for the neuron.
All in 1/100th of a second!
SYNAPTIC CLEFT &
NEUROTRANSMITTERS
 Neurons don’t actually touch
 Synaptic Cleft-microscopic gap between the terminal button of
one neuron and the cell membrane of another neuron
 This gap must be jumped in order for neurons to communicate
 Presynaptic neuron- sends signal
 Postsynaptic neuron- receives signal
 How does this happen?
 The arrival of an action potential at an axon’s terminal triggers the
release of NEUROTRANSMITTERS- chemicals that transmit
information from one neuron to another
 Collected together in little sacks called SYNAPTIC VESICLES
 Vesicles fuse together with the membrane and spill contents into the
synaptic gap
 They may bind to certain areas at various receptor sites
ALL-OR-NONE (PRINCIPLE) LAW
 The neural impulse is like a toilet, either it fires or it doesn’t
fire
 Action potentials are all the same size as well
 Neurons convey information about the strength of a stimulus
by varying the rate at which they fire action potentials
 Stronger stimulus- more rapid volley of neural impulses than a
weaker stimulus
FLUSHING NEURON-CAT
 Write these out on a separate sheet of paper (label and EXPLAIN)









All-or-Nothing Principle
Refractory Period
Resting Potential
Action Potential
Dendrites
Axon
Myelin Sheath
Terminal Buttons
Soma
 Watch the cat again, however this time, watch it and imagine that the
toilet flushing is like a neuron firing
 https://www.youtube.com/watch?v=H2W8XKK -3Rk&feature=youtu.be
NEUROTRANSMITTERS
Neurotransmitters
(chemicals) released
from the sending
neuron, travel across
the synapse and bind
to receptor sites on
the receiving neuron,
thereby influencing it
to generate an action
potential.
OCD
High blood pressure
Neurotransmitters bind to the receptors of the
receiving neuron in a key-lock mechanism.
Each neurotransmitter has an unique chemical configuration…
Neurotransmitters attach to specific receptors…like a puzzle piece fitting into
its proper place, receptors will only accept or recognize one type of
neurotransmitter
NEUROTRANSMITTERS
ACETYLCHOLINE
 Acetylcholine (often abbreviated ACh) is the most common
neurotransmitter. It is located in both the central nervous and
peripheral nervous system
 Acetylcholine was the first neurotransmitter be identified in 1914
 As a neuromodulator it acts on basic autonomic and muscular
fuctions
 Sarin Gas disrupts its ability to function and often leads to death
Neurotransmitters
Dopamine
Generally involved in regulatory motor
activity
In the basal ganglia, involved in mood,
sensory perception, and attention
NEUROTRANSMITTERS
Glutamate
Is an excitatory neurotransmitter
Plays a role in learning and memory
Too much can cause seizures
Malfunction of glutamate has also been
associated with Alzheimer's’
NEUROTRANSMITTERS
Epinephrine
Also known as adrenaline
Causes the feeling of being
“revved up” or on edge
Activates a “fight or flight” reaction in the
autonomic nervous system
NEUROTRANSMITTERS
Serotonin
Attention and other complex cognitive
functions, such as sleep (dreaming), eating,
mood, pain regulation
 Neurons which use serotonin are distributed
throughout the brain, stomach and spinal
cord
 Mood disorders
NEUROTRANSMITTERS
GABA
(gamma-aminobutyric acid)
GABA is the most important and common
inhibitory neurotransmitter
Stops the brain from becoming overexcited
Too much may cause hallucinations
AGONISTS
E FFECTS
ANTAGONISTS
OF DRUGS ON
N.S.
Block actions of
neurotransmitters
Mimic actions of
 Occupy receptor site &
neurotransmitters
prevent action.
Bind to receptors &
 a molecule, that by binding
generate PSP’s
to a receptor site, inhibits or
a molecule that, by
blocks a response
binding to a receptor
 Botulin (poison found in
site, stimulates a
improperly canned food) causes
response
paralysis by blocking ACh
Opiate drugs can
release
produce a temporary
 We call it Botox and inject it into
our faces to paralyze underlying
“high”
•
•
•
•
•
facial muscles 
Outside substances, that mimic (Fit) into
receptor site for neurotransmitter
Similar enough in structure that it
mimics the neurotransmitters
effect on the receiving neuron –
often agonists INCREASE
activity by inhibiting reputake
Sends message over and over
again! (Drugs and effectiveness)
“Master Key”
Similar enough to occupy the
receptor site and block its
action, but not similar enough
to stimulate activity
“Other Key”