Biology Neurotransmitters

Pair-share

How do you think chemicals in our bodies impact our behavior?(Discuss with your table partner).

Nervous SystemQ: Why do psychologists study the brain and the

nervous system?

A: Some biological functions underly human behavior, and in order to form a fuller understanding of ourselves,

it’s important to recognize what aspects of our behavior we can attribute to our own bodies.

Psychologists who examine behavioral problems based on the ways in which our bodies affect our behavior are using the “biological” or “neuroscience” approach. Psychologists who specialize in studying the effects of biological functions on

behavior are called “behavioral neuroscientists.”

Nervous System

You have about 1 trillion nerve

cells in your body, and 100 chemicals that

transfer messages

between those nerves.

(Those chemicals are called

neurotransmitters).

Nerve Ending (outgoing)

Neurotransmitters

Neurotransmitters stimulate the nerve endings, or transmit electrical impulses from the brain to the body.

Nerve Ending (incoming)

Neurotransmitters(Chemicals that travel

between neurons)

(Axon)

(Dendrite)

Synapse (gap)

NeurotransmittersNeurotransmitter Name Function

Acetylchloline Movement control, thinking/comprehending

Glutamate Memory

Gamma-amino butyric acid (GABA) Eating, sleeping, aggression

Dopamine Movement control, attention, pleasure and reward feelings

Serotonin Eating, sleeping, mood, pain, depression,coping with stress

Endorphins Pain suppression, pleasurable feelings, appetite

NeurotransmittersAn excess or lack of neurotransmitters

can impact our behavior.

For example, Parkinson’s Disease causes the brain

cells that produce dopamine to die. The

lack of dopamine in the body leads to shaking,

irregular movements, and loss of motion control. Lack of dopamine also depresses your mood,

which affects your personality and habits.

NeurotransmittersAn excess or lack of neurotransmitters

can impact our behavior.

Dopamine is also associated with motivation and

reward. When we do things like eating,

exercise, and romancing,

dopamine is released in our brains.

Too much is also bad: studies show that unusually high amounts of dopamine in our bodies is related to schizophrenia.

Drugs & The BrainCertain drugs like cocaine cause a temporary

overproduction of dopamine, mimicking the reward sensation. In other words, cocaine gives you a greater feeling of reward than the things that naturally cause dopamine production. The result of this is addiction.

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Dop

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Time Time

CocaineExercise, eating,

kissing/sex, winning

NeurotransmittersEndorphins block pain in your body, and are also

responsible for feelings of pleasure or happiness. A lack of endorphins may be responsible for certain forms of mental illness such as obsessive-compulsive disorder.

Endorphins are released when you exercise, and also when you experience pain.

Some people who engage in self-hurting behaviors may do so in part to feel the

feelings of euphoria prompted by controlled

amounts of self-inflicted pain.

NeurotransmittersAcetylcholine deficiency is an

abnormally low level of acetylcholine. This

neurotransmitter is involved in the control of muscle movement, learning, and memory formation. A lack of it causes uncontrolled muscle movements and difficulty forming and retrieving memories. Serotonin is a

neurotransmitter greatly involved in your mood. If you’re

feeling pessimistic, sad, distrustful, unconfident, or have panic attacks, you may have a

serotonin deficiency.

NeurotransmittersToday in modern medicine, drugs that stimulate

neurotransmitter production are being tested to see if they help relieve symptoms of clinical depression.

Symptoms of depression: Loss of interest Loss of appetite Loss of energyFeelings of lonelinessFeelings of worthlessnessAnger or irritabilityConcentration problemsReckless behavior

CausesWhat causes you to have too much or too little

of a neurotransmitter in your body?

Genetics: If family members have a chemical deficiency, it may

be passed on genetically.

Poor Nutrition:

Your diet impacts your bodily

chemicals (and obesity does too).

Stress: Stress can raise

or lower certain your

bodily chemicals.

Disease: Related to genetics:

Parkinson’s,Alzheimer’s,

and other diseases cause chemical

imbalances.

Drugs: Taking certain drugs confuses your body into

releasing chemicals when it has no

natural reason to.

Lack of Exercise:

Can cause problems like high blood pressure that

lowers blood-flow to your brain.

Alcohol, Smoking: Both cause

direct damage to the brain tissues.

Lack of Sleep:

Lowers blood flow to your

brain.

Brain Imaging

Brain ImagingTwo types of brain scans - PET scans and SPECT scans -

show how much activity is going on in the brain. “Activity” is measured by neurons firing, increased blood

flow, and/or release of brain chemicals.

This is a PET scan. After scanning thousands of

brains, researchers identified what “normal” levels of

brain activity looks like. If a brain shows activity higher

or lower than a normal brain, we know there is

something wrong.

Brain ImagingTwo types of brain scans - PET scans and SPECT scans -

show how much activity is going on in the brain. “Activity” is measured by neurons firing, increased blood

flow, and/or release of brain chemicals.

This is a SPECT scan. The healthy brain

will have a smoother shape with even brain activity. A brain with

problems will be shaped with holes or

lumps.

Brain ImagingTwo types of brain scans - PET scans and SPECT scans -

show how much activity is going on in the brain. “Activity” is measured by neurons firing, increased blood

flow, and/or release of brain chemicals.

For example, a SPECT scan can help us see if a

person’s brain is not producing enough of a

neurotransmitter, or is producing

too much.