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NEUROTRANSMITTERS

Neurotransmitters - · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

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Page 1: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEUROTRANSMITTERS

Page 2: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEURONS

Neurons don’t actually touch

Separated by a tiny fluid-filled gap called a

synapse

Neural impulses must be ferried across the

synapse by chemical messengers called

neurotransmitters.

Page 3: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEUROTRANSMITTERS

Biochemical substances that are released into

the synaptic cleft to stimulate or suppress

other neurons.

Dozens of neurotransmitters have been

identified.

Page 4: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEUROTRANSMITTERS

Contraction of muscles to move our bodies

Release hormones

Psychological states of thinking and emotions

Page 5: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEUROTRANSMITTER

Each type of (NT) has a three-dimensional

shape.

Page 6: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NEUROTRANSMITTERS

The journey across the synapse takes only a

thousandth of a second.

Page 7: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NT

Changes have either an excitatory effect or an

inhibitory effect.

Page 8: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

EXCITATORY

Green light: “yes”

Just do it!

Activates the next cell

Makes an action potential more likely to occur

How? hooked to a positive ion

channel….happens slowly

Page 9: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

INHIBITORY

Red light

Just say no

Less likely that the cell would fire

Hooked on to a negative ion channel

Page 10: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NT

Some NT have only Excitatory effects

Some NT have only Inhibitory effects

Some NT have both

Page 11: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

PREVENTING THE ENT FROM STIMULATING

A RECEIVING CELL

1. Reuptake: NT not taken up by the receiving cell are reabsorbed by their vesicles to be used again. Nature’s own version of recycling.

1. Enzymes: organic substances in the synapse break down NT, which are then eliminated from the body in the urine.

Page 12: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

CONTINUE FROM PREVIOUS SLIDE…

3.Neuromodulators: terminal buttons release

these chemicals that either increase or

decrease the sensitivity of the receiving neuron

to NT.

Page 13: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

NT

NT originate in the body

Drugs originate outside of the body.

Page 14: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

DRUGS/CHEMICALS OUTSIDE OF THE BODY

Antagonists: drugs or chemicals that block the

actions of NTs by occupying their receptor sites.

Antagonists prevent transmission of the messages

carried by the NT

Compete with NTs at the same receptor sites

Page 15: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

DRUGS/CHEMICALS

Agonists: drugs that either increase the

availability or effectiveness of NT or mimic their

actions.

Page 16: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

5 NT THAT STUDENTS NEED TO KNOW

1. Acetylcholine (ACh): NT that enables motor

function in the body. Ex. Wiggle my fingers.

makes muscles contract (motor cortex)

Role in learning and memory.

If ACh transmission is blocked, the muscles

cannot contract.

Page 17: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

ACH

Underproduction of ACh is an important factor in Alzheimer’s disease

Reductions in ACh weaken or deactivate neural circuitry that stores memories.

Absence: Paralysis

Oversupply: violent muscle contractions

Certain spider bites/Black widow

Page 18: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

5 NT THAT STUDENTS NEED TO KNOW

2. Endorphins: natural chemicals released in the

brain that have pain-killing and pleasure-inducing

effects. Blocks pain.

Inhibitory NT

Located in the Brain, pituitary gland, and spinal cord.

“runners high”

Morphine and heroin are agonists since they mimic

the effects of endorphins.

Page 19: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

5 NT THAT STUDENTS NEED TO KNOW

3. Serotonin: affects mood, hunger, temp regulation

and sleep.

Inhibitory or excitatory

Located in the brain stem, cerebellum, pineal gland,

and the spinal cord.

Undersupply may lead to depression, sleeping and

eating disorders.

Oversupply linked to OCD

Page 20: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

SEROTONIN

Prozac acts as a agonist

Prozac elevates serotonin levels

Some other antidepressant drugs raise

serotonin levels

Page 21: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

5 NT THAT STUDENTS NEED TO KNOW

4. Dopamine: influences body movement, learning,

attention, reward experiences, and emotion.

Located in the brain and the peripheral nervous

system.

excess dopamine receptor activity linked to

schizophrenia.

Antipsychotic drugs like Theorize are antagonists that

block receptor sites for dopamine.

Page 22: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

DOPAMINE

Parkinson’s Disease: a degenerative brain disease that leads to a progressive loss of motor function. Experience tremors, shakiness, rigidity, and difficulty in walking.

Lack normal levels of dopamine.

Ex. Michael J. Fox

Muhammad Ali

Page 23: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

5 NT THAT STUDENTS NEED TO KNOW

5. Gamma-aminobutyric acid (GABA): a major inhibitory NT.

Regulates nervous activity by preventing neurons from overly exciting their neighbors.

Located in the retina, spinal cord, hypothalamus, and cerebellum.

Exists in as many as a third of all synapses.

Drugs that boost GABA’s effects have a calming or relaxing effect.

Reduced levels of GABA may play a role in emotional disorders in which anxiety is a core feature.

Page 24: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

GABA

Alcohol and antianxiety drugs like Valium, act as

agonists

Rohypnol (roofies): suppress general neural activity by

enhancing the action of GABA. Rohypnol is 10 times

more potent than Valium

Coma, amnesia, respiratory depression, and death.

Page 25: Neurotransmitters -   · PDF fileneurotransmitters. NEUROTRANSMITTERS ... Dopamine: influences body movement, learning, attention, reward experiences, and emotion

ASSESSMENT QUESTION

A scientist develops a drug that blocks the actions of cocaine by locking into the same receptor sites as cocaine. So long as a person is taking the drug, cocaine will no longer produce a high. Would this drug be an antagonist or an agonist to cocaine? Why?