What are Neurons? - PowerPoint Presentation

Slide1

What are Neurons?What are Neurotransmitters?What Part Do They Play in Mental Illness?

Developed by Roger F. Cram Hiram College in Hiram, Ohio 44234Copyrighted © with all rights reserved January 2011, October 2011, July 2012 NAMI (National Alliance on Mental Illness)Portage and Geauga Counties in OhioJuly 30, 2012Although copyrighted, permission is granted for use by any NAMI organization.Slide2

Electrical signals travel from the brain along the neurons (wires) to a particular device like a muscle cell, a heart cell, lungs, eyes, ears, liver, a feeling, a thought, an emotion, a dream, etc. Neurons in the brain - illustration. Credit: Benedict Campbell.neurons from www.images.wellcome.co.ukSlide3

What

do neurons look like?There are 10 billion nerve cells in the brain.IMAGES FROM RESEARCH - NEURONS AND NEURONAL PROTEINS by Robert S. McNeil Transductions – neurons – Feb. 4th, 2010 by WolfSlide4

Soma(Cell Body)

AxonMyelinDirection of electrical charge to the next neuronCell nucleus

Dendrites:

Electric-

charge

receivers

Axons:

Electric charge

transmitters

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide5

How Does a Neuron Carry An Electrical Charge? Neurons attach to each other through the synapse gap (doorbell button or electric switch) carrying an electrical charge from one neuron to the other. These neurons form the “wires” or nerves carrying information throughout our body. Slide6

Electrical Connection

Often many neurons are linked together where the dendrite connects to the axon carrying electrical signals along their path.AxonDendrite

Direction of current flow

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide7

SWITCH

Dendrites Connected to Axons Act Like Electric Switches Allowing an Electrical Charge to Move Along a Wire

Axon

Dendrite

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide8

Involuntary Neurons Neurons are used to carry electrical signals for involuntary processes: digest your food, keep your heart beating, repair cells, clean your blood, create thoughts and emotions (fear, lust, jealousy, self-esteem), carry light images from your eyes to your brain, create hearing-touch-taste-smell, fight disease, grow a baby, create the sensation of hunger, etc….Slide9

Voluntary Neurons Neurons are also used to carry electrical signals for voluntary movements like moving muscles (running, walking, writing, working, typing, taking a bath, getting dressed, driving a car) or for thinking (solving a problem, creating art, reading a book, meditating, imagining things).Slide10

Neuron SignalsYour brain triggers six trillion electrical signals through your neurons every second to operate your body and allow you freedom of thought, movement and life.How much is six trillion? Well, six trillion pennies stacked end-on-end, would go from the earth to the moon, 243,000 miles, twenty-four

times! Mental illness is a disease of these electrical circuits in the brain.Slide11

The electrical signal is passed from one neuron to the next to the next until it is either blocked or it reaches its targeted device (muscle, thought, heart beat, eye, tongue, hand, etc.). That’s how memory works, how the entire body works, how we think, how our emotions make us aware of pleasure, panic, and sorrow; that’s how we run, speak, fight disease, heal a scratch, see, hear, taste, touch, yell at our kids – all through electrical connections going through nerves carried from one neuron to the next. Slide12

Synapse Connection (switch) Axon Connected to a Dendrite

)AxonDendriteSource: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide13

What does the connection of two neurons look like?Synaptic Cleft (the gap)

Electrical ConnectionAxon endDendrite endThe Brain Bank Your plastic brainPosted on June 20, 2011 by Brain Bank Manc Slide14

End of first

neuron

Start of next neuron

AXON TERMINAL END

Dendrite End

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide15
Slide16

The Synapse Gap Neurons, although they carry the electrical charge from one neuron to the next, are not actually touching each other, but separated by a very small gap called the “synapse cleft or gap” serving as an open switch or doorbell button. Something must happen to push the doorbell button, to throw the switch, to carry the electrical charge across this

gap to the next neuron. Slide17

Start of next neuron

Incoming electrical

charge

AXON TERMINAL END

Dendrite

Gap or

Synaptic Cleft

There is a gap or empty space between the two

connecting neurons.

End of first neuron

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide18

When an electrical charge reaches the end of the first neuron at the axon, it causes vesicles, being tiny bags containing chemical neurotransmitters, to drop down and release their contents into the synapse cleft or gap. The yellow round molecules represent one of over 100 different chemicals your brain uses as neurotransmitters to carry the electrical charge across the gap to the

dendrite receptors, being the next neuron. This transfer of electrical-to-chemical-to-electrical information is how the brain controls all functions necessary for life.

AXON

Vesicles

Neuro

-

transmitters

Dendrite

ReceptorSlide19

Let’s take another look at this illustration. Notice the vesicles?Synaptic Cleft (the gap)Electrical Connection

Axon endDendrite endThe Brain Bank Your plastic brainPosted on June 20, 2011 by Brain Bank Manc Slide20

Start of next neuron

Continuation of charge to

next neuron.

Incoming electrical

charge

AXON TERMINAL END

Dendrite

Receptor

Vesicle

Neurotransmitter

(Serotonin)

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Source: NAMI–Family to Family Course, Class 6, Handout 2–Basic

Neuro

-transmission at the Synapse–page 6.23 Paragraph 3Slide21

NeurotransmittersIf the neurotransmitter (chemical making the electrical connection between two neurons) is in the part of the brain controlling the beating heart, the electrical impulses will go along the chain of neurons to the heart muscle causing it to pump.If the neurons are in the part of the brain controlling voluntary muscle control, and you are trying to wave good-bye, the electrical

impulses will go along a chain of neurons to the muscle cells in the arm allowing you to wave good-bye.Slide22

If the neurons are in the part of the brain controlling emotions, and you are in a crisis situation, instinct will trigger the electrical neurotransmitter impulses resulting in the fight-or-flight response and the necessary emotions and muscle action (fighting, yelling, threatening, blocking an attack, fleeing, running, jumping out of the way, etc.).

NeurotransmittersSlide23

If the neurons are in the part of the brain controlling emotions and you are Bipolar, extra neurotransmitters may carry excessive electrical “good feeling” impulses (manic) or insufficient neurotransmitters may carry a deficient amount of “good feeling” impulses (depression) without your permission. The neurons and neurotransmitters simply take over. This is what many experts think happens with bipolar, but they’re not absolutely sure.

NeurotransmittersSlide24

In the following illustration, the neurotransmitter is serotonin (yellow circle ) and it carries the electrical charge from the axon into the gap. When enough serotonin binds into the receptors of the next neuron, the electric charge will be forwarded. This communication between neurons is brief, lasting about 1 millisecond.Slide25

Start of next neuron

Vesicle

Continuation of charge to

next

neuron

Incoming electrical

charge

AXON TERMINAL END

Dendrite

Receptor

Neurotransmitter

(Serotonin)

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide26

The serotonin molecules are shown as round and the receptors (docking sites) that receive them are the correctly sized semi-circular dish so the round serotonin molecule fits perfectly into the receptor, thus transmitting the electric charge. Source: NAMI – Family to Family Course, Class 6, Handout 2 – Basic Neuro-transmission at the Synapse – page 6.23

Start of next neuron

Gap or

Synaptic Cleft

Vesicle

Continuation of charge to

next neuron.

Incoming electrical

charge

AXON TERMINAL END

Dendrite

Receptor

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide27

If a chemical other than the round serotonin molecule were to enter the synapse gap, assuming each molecule has a unique molecular shape, it would probably not fit into the receptor being a different shape, and therefore not transfer the electrical charge to the next neuron.

Start of next neuron

Continuation of charge to

next neuron.

Incoming electrical

charge

AXON TERMINAL END

Dendrite

Neurotransmitter or

chemical other than Prozac

Receptor

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Will not fit into receptor;

therefore, will not carry

forward a charge.Slide28

Once the neurotransmitter, in this case the yellow serotonin, delivers the electrical charge to the receptors of the next neuron, its job has been completed – it has delivered its message. New messages (electrical charges) will soon be coming down from the axon in other vesicles so the “used” serotonin must leave the synapse cleft or gap so it does not interfere with the new messages.Slide29

The serotonin is released from the receptor and then removed from the gap two ways: (1) an uptake pump passes the serotonin back up into the original axon from which it came (2) a chemical enzyme metabolizes the serotonin getting rid of it. Source: NAMI – Family to Family Course, Class 6, Handout 2 – Basic Neuro-transmission at the Synapse – page 6.23 paragraph 6 Slide30

In the next illustration, notice the addition of the uptake pump. It is the correct size and shape to remove the serotonin molecule. Serotonin is removed from the gap by passing into the uptake pump and delivered back into the axon. Source: NAMI – Family to Family Course, Class 6, Handout 2 – Basic Neuro-transmission at the Synapse – page 6.23 1) ReuptakeSlide31

Start of next neuron

Continuation of charge to

next

neuron.

AXON TERMINAL END

Dendrite

Uptake

Pump

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Serotonin molecules being released by the receptor after they delivered their charge. They are going to the uptake pump.Slide32

Sometimes an enzyme, released from the axon, breaks down the serotonin molecules and removes them from the synapse cleft. This “clean-up enzyme” action, where the serotonin is metabolized (broken down) is a second way of removing a neurotransmitter from the gap serving the same purpose as the uptake pump. Source: NAMI – Family to Family Course, Class 6, Handout 2 – Basic Neuro-transmission at the Synapse – page 6.23 2) Metabolism

Entering enzyme is shaped to remove serotonin molecule from the synapsecleft area.Forward motionof enzyme.

Serotonin

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide33

Start of next neuron

Continuation of charge to

next neuron.

AXON TERMINAL END

Dendrite

Receptor

Clean-up

enzyme

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Serotonin being

metabolized

(broken down) by

the enzyme.Slide34

Neurotransmitters and Emotions

*****UNDERSTAND THIS***** In the emotional sections of the brain, the electrical charge created by neurotransmitters through the synapse gap IS our sensation and awareness of life. It is where emotions are created, felt, and realized. It is where we experience life and are aware that we exist!Slide35

Neurotransmitters These neurotransmitters (Over 100 different chemicals like dopamine and serotonin) are critical in understanding how we feel, our moods, our aggression, our stress levels, how we function, how we think, and whether or not we are in a nurturing relationship or locked in a straight jacket. Slide36

Neurotransmitters That sudden sadness you feel when hurt by some one you love is felt because of neurotransmitters. That panic you feel when suddenly frightened is felt because of neurotransmitters. “Road rage” is felt because of neurotransmitters. Are you afraid of spiders or high places? Are you bipolar and experience depression and manic episodes? Do you have panic attacks? OCD? ADHD? Yep – neurotransmitters!Slide37

Neurotransmitters If your “feel good” neurotransmitters are sufficient you will most likely experience happiness, motivation, focus, emotional stability, good feelings toward others, and calmness through difficulties. Slide38

Neurotransmitters If your “feel good” neurotransmitters are deficient you may feel depression, panic or anxiety, sleeplessness, moody periods, irritability, over aggressiveness, and stress.Slide39

NeurotransmitterIts FunctionToo MuchToo LittleSerotoninMood regulation, hunger, sleep, problems with anger control, sexual desire, decreased anxiety

Depression, obsessive-compulsive disorder, and suicide, irrationalDopamineMotor movement and alertness/ attention, good feelings, aggression, thinking, planningParkinson's diseaseSchizophrenia, lack of remorse, inability to feel love or affectionEndorphinsPain control, stress reduction, feelings of pleasure, "natural opiates“ Potentially involved in addictionSense of inadequacy, inability to combat painAcetylcholine AChCritical to motor movement, learning, and memory; has a part in scheduling REM (dream) sleep. Alzheimer's and muscle disorders.GABA (gamma-aminobutyric acid)Brain's major inhibitory neurotransmitter, reduced anxiety, reduced insomniaSeizures, insomnia, anxiety disorder, epilepsy, racing thoughtsNor epinephrine"Fight or Flight,“ controls alertness, arousal, elevates heart rate, circulation, respiration, and mood elevationDepressed mood, racing heart, manic, elevated blood pressureLack of energy, lack of drive, reduced focus on goals

Glutamate

Brain's major excitatory neurotransmitter, creates links between neurons that form basis of learning, long-term memory

Lou Gehrig's disease

Over stimulation of the brain, seizures

General Psychology – Neurotransmitters - Dr. C. George

Boeree

2009; Healthy Botanicals

Some Types of Neurotransmitters and Their FunctionSlide40

Dopamine and SerotoninPathways in the Brain

NIDA National Institute on Drug Abuse July 2008 - Addiction Science: From Molecules to Managed CareSlide41

When sufficient serotonin or dopamine or another “feeling” neurotransmitter is in the synapse cleft “the gap,” feelings of peace and less agitation are enjoyed. When an insufficient amount is in the gap, feelings of agitation might be experienced. Slide42

If a way could be found to keep the serotonin in the cleft for longer periods of time before it is removed by the uptake pump or enzyme, then more peaceful feelings and less stress could be experienced. Slide43

Prozac and Zoloft are called “serotonin reuptake inhibitors.” Their molecular shapes imitate the shape of the serotonin molecule. They assume the role of serotonin in the synapse cleft confusing the uptake pump or the clean-up enzyme into removing the Prozac or Zoloft instead of the serotonin; thus the serotonin stays longer in the cleft connecting to the receptors and increasing feelings of peace, self-esteem, and well being.Slide44

Serotonin

Prozac

Cleft

Entering

capture-

enzyme

Notice the pink molecules.

They represent the drug Prozac. Although their molecular shape is different

than the yellow serotonin molecules,

it is similar enough to fit

into the uptake

pump;

therefore, when the uptake

pump eliminates

some of the pink molecules

(Prozac) instead

of the serotonin, more serotonin molecules will remain in the

gap

increasing

connections with the receptors, passing on their charge, and creating more peaceful feelings of wellbeing.

Electric Charge

Charge moving

on to next neuron

AXON

DENDRITE

GAP

Uptake pump removing ProzacSlide45

Dopamine Dopamine is a neurotransmitters like serotonin playing an important role in our “reward” and “pleasure” centers and is instrumental in regulating many normal and pathological behaviors. Slide46

Uptake

Pump removing

Dopamine

Dopamine

Cleft or Gap

All

anti-psychotic drugs

prevent dopamine from binding to the receptors on the receiving cell neuron (dendrite). This blocks the electrical charge from going on to the next neuron, thus blocking the

stressful emotion

inherent in the

neurotransmitter.

Axon

Gap

Dendrite

Axon end

Dendrite end

Gap

Receptors

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Source: NAMI – Family to Family Course, Class 6, Handout 2A – Basic

Neuro

-transmission at the Synapse – page 6.24

Anti-psychotic drug entering receptors blocking dopamine from carrying the feeling charge to the next neuron.Slide47

Instinct and NeurotransmittersHomo Sapiens Sapiens, being us - modern-day humans - instinctually, need to feel good about themselves, to develop feelings of self-worth and accomplishment which results from endorphins, serotonin, dopamine, and other “feel good” neurotransmitters entering the “synapse gap.”When something occurs indicating a boost in self-worth is justified (graduating from school, winning a game or race, giving birth, completing a project, falling in love, getting public recognition for accomplishments, etc.) endorphins and other “feel good” neurotransmitters are triggered to enter the “synapse gap” in the emotional part of the brain.Slide48

Unfortunately, there are easier ways to feel the wonderful sensations and euphoria created in the “synapse gap” without completing a great accomplishment.Alcohol, marijuana, caffeine, cocaine, heroine, nicotine, and other recreational drugs increase the levels of dopamine because of their similar molecular shapes. They “fool” the uptake pump into eliminating them from the gap, thus increasing dopamine levels and the associated feelings of well being. LSD, mescaline, and ecstasy work by attaching to serotonin receptor sites and thereby blocking emotional signals from connecting to the receptors of the next neuron. General Psychology 2009 Neurotransmitters Dr. C. George

Boeree Recreational Drugs and NeurotransmittersSlide49

Dopamine

Cleft

Neurotransmitters and Feelings

Humans

seek pleasure and avoid pain. Feelings of pleasure and euphoria come from

great accomplishments.

They also come from artificial stimuli like drugs.

Charge from axon

Cocaine

Marijuana

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Uptake pump removing marijuana

& cocaine

More dopamine in the gap connecting with the receptors.Slide50

Morphine Morphine reduces pain and is often given to patients in hospitals and the wounded on battle fields for this purpose. The morphine molecule has a similar shape as the neurotransmitters in the neurons transmitting pain signals, but the morphine molecule will not carry the electrical charge forward to the next neuron once it is in the receptor, thus blocking the pain signal.Slide51

Start of next neuron

Neurotransmitter

in pain-sending

neuron.

Continuation of charge to

next neuron.

AXON TERMINAL END

Dendrite

Receptor

Morphine molecule

blocks pain signal - no

electric

charge is

carried

forward

– thus

pain

is reduced

Morphine Molecule – a pain reducer

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. CramSlide52

Medicine Side EffectsWhen medicines are introduced into the human body they unfortunately do not only enter the cells and neurons associated with the illness they are trying to relieve, but other areas of the body and brain as well. Medications designed to treat schizophrenia affect the neurons associated with that disease in the brain, but they also connect with the neurons that affect saliva regulation; thus one of the side effects of these

medications is dry mouth.Slide53

Medicine Side EffectsMedicines also enter the synapse gaps of neurons that control muscles, heart rate, vision, weight gain, constipation, nervousness, anxiety, insomnia, headaches, nausea, and many others. These medications interfere with the neuron’s neurotransmitter keeping it from performing its normal function (heart rate, vision, muscle movements, etc.) by blocking the receptors, stopping the uptake pump, stopping the metabolizing enzyme, or by having the uptake pump remove the medicine instead of the existing neurotransmitter.Slide54

Medicine Side EffectsProlixin is a drug frequently prescribed for schizophrenia because it helps eliminate delusions and social withdraw by affecting the neurotransmitters causing the disease.Prolixin also enters other neurons in the brain that control muscle movements (hand tremors are created), that influence the eyes (blurred vision is a side effect), and that control the heart (a rapid heart beat can result). Source: NAMI – Family to Family Course, Class 6, Handout 9 – First Generation Typical Narcoleptic Medications – page 6.36 Slide55

Prozac and Zoloft are drugs called reuptake inhibitors and they do their work in the gap by being absorbed by the uptake pump leaving more serotonin in the gap. When more serotonin is in the gap, there is more chance for stimulation by the serotonin at the receiving receptors, thus increasing feelings of wellbeing.Anti- depressant medications do not interfere with neurotransmitter transmissions across the gap like Prozac does, but instead they block the reuptake pump, thus leaving more neurotransmitters in the gap to react with the receptors of the next neuron.Anti-depressant drugs called MAO inhibitors prevent the metabolic

breakdown of neurotransmitters by interfering with the removing enzyme, thus leaving more neurotransmitter in the gap.Anti-psychotic drugs block the dendrite’s receptors from carrying the charge to the next neuron, thus blocking the painful emotional signals.Source: NAMI – Family to Family Course, Class 6, Handout 2 – Basic Neuro-transmission at the Synapse – page 6.24Slide56

AXON TERMINAL END

Dendrite

Receptor

Prozac

Anti-depressant medications block the uptake pump

Reuptake inhibitor

drugs – Prozac & Zoloft – are absorbed by the uptake pump leaving more serotonin in the gap for the receptors

Anti-psychotic drugs block the receiving

receptors from carrying the charge to the next neuron

Anti-depressant

MAO inhibitors

prevent the enzyme

f

rom breaking down the neurotransmitter

Source: Modeling Future Heroes, A Practical Application of Heroic Values, By Roger F. Cram

Source: NAMI–Family to Family Course, Class 6, Handout 2A–Basic

Neuro

-transmission at the Synapse–page 6.24Slide57

Some Diseases Involving NeuronsBipolar disorderCerebral PalsyParkinson’s Disease

SchizophreniaPanic attacksObsessive-compulsive disorder (OCD)DepressionEpilepsyAlzheimer's DiseaseAttention Deficit Disorder (ADD / ADHD)Multiple SclerosisAutismTurret's SyndromeSlide58

Brain disorders and mental illness are often caused by an over or under developed portion of the brain. Neurons misfiring, too much of a neurotransmitter, and more often, a neurotransmitter deficiency are contributing factors. An irregular brain development during adolescence is often suspected for causing mental illness or an injury or a suspicious gene deciding to fire at the beginning of puberty. Slide59

Many of the causes of mental illness and brain disorders are still a mystery with research continuing every day. But one thing is for sure, whatever the causes and treatments that are discovered, you can bet neurons and neurotransmitters will play an intricate role.Image Source Page: http://colinfarbotko.blogspot.com/2010_04_01_archive.htmlSlide60

The End of this presentation……the beginning of hope. Picture Source: Genetic Engineering and Biotechnology News May 4th 2011Slide61

NIDA National Institute on Drug Abuse July 2008 - Addiction Science: From Molecules to Managed CareModeling Future Heroes, a Practical Application of Heroic Values, by Roger F. Cram, book in progressNAMI (National Alliance of Mental Illness) nami.orgNAMI – Family-to-Family Teacher’s ManualGenetic Engineering and Biotechnology News, May 4, 2011neurons from www.images.wellcome.co.ukThe Brain Bank Your plastic brainPosted on June 20, 2011 by Brain Bank

Manc Neurons in the brain - illustration. Credit: Benedict CampbellGeneral Psychology – Neurotransmitters - Dr. C. George Boeree 2009 Healthy BotanicalsIMAGES FROM RESEARCH - NEURONS AND NEURONAL PROTEINS by Robert S. McNeil Transductions – neurons – Feb. 4th, 2010 by WolfNIDA National Institute on Drug Abuse July 2008 - Addiction Science: From Molecules to Managed CareSources of Material and Photo Credits: