Transcript Specialized Neurotransmitters Dopamine

NEUROTRANSMITTERS
A NEUROTRANSMITTER is a chemical substance
that is used by one neuron to signal another.
• Some are made in the cell body while others are made in the
neurotransmitter swellings. The impulse is changed from and
Electrical Impulse to a Chemical Impulse (Electrochemical
Impulses). The molecules of the neurotransmitter diffuse across the
gap and attach themselves to SPECIAL RECEPTORS on the
membrane of the neuron receiving the impulse. This now causes the
electrical impulse to be regenerated. After the neurotransmitter
relays it message it is rapidly REMOVED or DESTROYED, thus
halting its effect. ENZYMES, taken up again by the axon terminal
and recycled, may break down the molecules of the neurotransmitter
or they may simply diffuse away.
Synapses are the slowest part of the nervous
system.
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The advantage to having many neurons,
with gaps between them, is that we can
control and receive information from
different parts of the body at different
times. They also ensure one-way
transmission of impulses in a living
person. The number of synapses
associated with each neuron varies from
1000 for a cell body of the spinal cord to
up to 10,000 for cell bodies in the brain.
To Review: The main functions of the
synapse are:
• 1. To transmit impulses from one neuron to another
neuron or to an effector.
• 2. To control the direction of the impulse. Impulses can
only go one way. The neurotransmitter swellings are only
found on the presynaptic side of the synapse. Thus, the
impulse can only travel from the presynaptic side to the
postsynaptic side.
• 3. To prevent over stimulation of effectors. Constant
stimulation causes neurotransmitter production to cease.
In this way we get used to stimuli such as pain or noise.
• 4. Certain chemicals can block the impulse. This is why
doctors prescribe certain drugs for pain relief.
Specialized
Neurotransmitters
Dopamine - Serotonin -Norepinephrine GABA – Glutamate-Acetylcholine
#1 ACETYLCHOLINE
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Acetylcholine was the first neurotransmitter discovered and is the major
neurotransmitter in the peripheral nervous system (the only other peripheral
neurotransmitter being norepinephrine). Acetylcholine is usually (but not
always) an excitatory neurotransmitter — in contrast to the monoamine
neurotransmitters, which are nearly always (with a few exceptions)
inhibitory.
There are comparatively few acetylcholine receptors in the brain, but
outside the brain acetylcholine is the major neurotransmitter controlling the
muscles. Body muscles can be divided into the skeletal muscles system
(under voluntary control) and the smooth muscles of the autonomic
nervous system (controlling heart, stomach, etc. — not under voluntary
control). The autonomic nervous system is further subdivided into
sympathetic and parasympathetic divisions. Direct innervation of skeletal
muscles is due to acetylcholine, as is the innervation of smooth muscles of
the parasympathetic nervous system. Direct innervation of the sympathetic
nervous system (except for sweat glands) is due to norepinephrine (or both
epinephrine & norepinephrine in the case of the adrenal medulla).
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#5 Dopamine
is often called the "Feel Good
Neurotransmitter!
When we have enough Dopamine we have . . .
Feelings of pleasure
Feelings of attachment/love
Sense of altruism (unselfish concern for the welfare of
others)
Integration of thoughts and feelings
ADD/ADHD medications target the Dopamine in our
Central Nervous System serving as proof that the
medical professionals believe that Dopamine (and the
related Neurotransmitter, Norepinephrine) are the
reasons for these problems
Dopamine Is One Of The
Most Important Nutrients
Needed By Your Body!
• Dopamine, along with Norepinephrine has come
to be recognized as playing a large role in
attention and focus. For people with ADD/ADHD,
psychostimulant medications such as
Ritalin/Concerta (methylphenidate), Dexedrine
(dextroamphetamine), and Adderall (a racemic
mixture of amphetamine salts) are prescribed to
help increase levels of norepinephrine and
dopamine.
When we have enough Dopamine
we have . . .
• Feelings of pleasure
• Feelings of attachment/love
• Sense of altruism (unselfish concern for
the welfare of others)
• Integration of thoughts and feelings
When we have Dopamine
Deficiencies . . .
• Anhedonia (lack of pleasure)
• Lack of ability to feel love, sense
attachment to another
• Lack of remorse about actions
• Distractibility
#6 Serotonin
• When we have enough serotonin, we feel
emotionally stable, we can sleep, we can
sort out the feelings and determine in a
logical manner if there is a threat present.
Serotonin . . . How Important Is
It?
• SEROTONIN: Promotes And Improves Sleep,
Improves Self Esteem, Relieves Depression,
Diminishes Cravings, Prevents Agitated
Depression And Worrying.
• Serotonin provides numerous calming and
stabilizing actions in the brain and body. When
we have enough serotonin, we feel emotionally
stable, we can sleep, we can sort out the
feelings and determine in a logical manner if
there is a threat present.
When we are low in serotonin,
• we feel immediately irritable and we are
overly sensitive to sights and sounds. We
have difficulty sleeping and may suffer
unexplained outbursts of tears.
When we have enough
Serotonin, we are . . .
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Hopeful
Optimistic
Calm
Patient
Creative
Focused
Responsive
Good Natured
In addition, we are . . .
Loving and Caring
Reflective & Thoughtful
Able To Concentrate
Able To Think Things Through
And we . . .
Don't Crave Carbohydrates
Sleep Well
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Good Dream Recall
But when we have a shortage of
serotonin, lookout! We are . . .
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Depressed
Anxious
Irritable
Impatient
Impulsive
Abusive
Reactive
A Real Pain
#2 Norepinephrine
• Norepinephrine, also known as
noradrenaline, is a neurotransmitter found
in the sympathetic nervous system.
The sympathetic nervous system
stimulates the heart, blood vessels, sweat
glands, the large internal organs, and the
adrenal medulla in the brain.
Norepinephrine
(Also Known As Noradrenaline)
• Like dopamine, norepinephrine has a stimulating effect, fosters
alertness, and plays an important regulatory role in long-term
memory and learning. It also protects endorphins from being broken
down prematurely.
• Optimal levels of this transmitter can stimulate a sense of wellbeing
or even create a euphoric effect in stressful situations . . .
• Yet excess norepinephrine can fuel the physiological expressions of
fear and anxiety, as may be the case for people who suffer from
anxiety disorders.
• The amino acid tyrosine, found in high concentrations in cheese, is
converted by specific reactions into at least two neurotransmitters . .
. norepinephrine and dopamine.
• Norepinephrine is produced from dopamine, with the help of the
amino acids phenylalanine, lysine, and methionine. Vitamins C and
B-6, magnesium, and manganese are important cofactors.
Norepinephrine Functions in:
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Arousal, energy, drive
Stimulation
Fight or Flight
Norepinephrine Deficiencies result in:
Lack of energy
Lack of motivation
First "state" called depression
#4 GABA
• GABA (gamma-aminobutyric acid) is the
most important and the abundant inhibitory
neurotransmitter in the brain (it's actually
an amino acid classified as a
neurotransmitter).
What Is Gaba?
• GABA helps induce relaxation and sleep.
• It also acts as a "balancer" for the brain
where excitation of the brain is balanced
with inhibition.
• Other studies have shown that GABA increases
the body's sleeping cycle and patients reported
much more vivid dreams. Getting a good night's
sleep and obtaining more rest can lead to more
energy throughout the day.
• GABA also has a slightly sedative effect, which
makes it ideal to take before going to bed.
#3 GLUTAMATE
• Glutamate is the most common
neurotransmitter in the brain. It is
always excitatory, usually due to
simple receptors that increase the
flow of positive ions by opening
ion-channels.