Download Neurotransmitters CHART

Common Neurotransmitters
Neurotransmitter
Function
Acetylcholine (Ach)
Enables Muscle Action (movement),
Learning, Memory
Examples of Malfunctions
Alzheimer’s disease: caused by too little
AcH; Ach-producing neurons deteriorate in
hippocampus causing memory problems
Excitatory
Botulism poison blocks Ach; leads to
paralysis of respiratory muscles
Black Widow spider bite – causes a release
of AcH by motor neurons – leads to violent
muscle convulsions
Dopamine
Inhibitory
Influences movement, learning,
attention, and emotion
Excess dopamine receptor activity linked to
schizophrenia (positive symptoms)
Strongly associated with reward
mechanisms in brain
Starved of dopamine, the brain produces
tremors and decreased mobility of
Parkinson’s disease
Contributes to the physical high
associated with drugs such as
cocaine, alcohol, opium, heroin,
nicotine… THESE DRUGS
INCREASE DOPAMINE
Serotonin
Affects mood, hunger, sleep, and
arousal, impulsivity
Inhibitory
An undersupply of dopamine is also linked to
depression.
Undersupply – linked OCD, anxiety, mood
disorders(depression), anger control,
insomnia, and suicide
Prozac and other antidepressant drugs in the
SSRI category (selective serotonin reuptake
inhibitors) increase serotonin levels in the
synapse (see additional handout)
Drinking warm milk at night helps you sleep
because warm milk contains an amino acid
that the brain uses to make serotonin (helps
you to relax)
Plays a role in schizophrenia, may interact
with dopamine system to alter the way it
operates.
Norepinephrine
Excitatory
Aka Noradrenaline
Helps control alertness and arousal;
associated with mood, sleep,
learning
Increases heart rate and slows
digestion during stress
*Role in perception: LSD attaches to
serotonin receptor sites blocking perceptual
paths
Undersupply can depress mood
Oversupply can lead to insomnia
Common Neurotransmitters
Neurotransmitter
GABA (gammaaminobutyric acid)
Inhibitory
Function
A major (best known) inhibitory
neurotransmitter
Excitatory
Undersupply linked to seizures, tremors, and
insomnia, anxiety, Huntington’s disease,
epilepsy
Associated with sleep; movement
Seems needed to keep neuron
activity “in check” (role as an
inhibitory neurotransmitter)
Glutamate
Examples of Malfunctions
Major excitatory neurotransmitter
Involved in memory
Most common in CNS – as much as
½ of all brain neurons release
glutamate
Curiously…Actually toxic to neurons
and an excess will kill them (see
next column: “Damage after stroke”)
Some anti-anxiety drugs, such as Valium,
work by enhancing effects of GABA
Too little GABA in some brain areas may be
a cause of epilepsy
Oversupply – overstimulates brain leading to
migraines or seizures (why some avoid
MSG, monosodium glutamate, in food)
Damage after stroke:
Sometimes brain damage or stroke leads to
excess glutamate and many more brain cells
die than from original trauma
ALS – (Lou Gehrig’s Disease) caused by
excessive glutamate production.
Schizophrenia – lack of glutamate
production. (negative symptoms, ex.
catatonic)
Many neurologists believe glutamate is
responsible for many CNS diseases
Endorphins:
(endogenous
morphine)
Short for Endogenous
morphine – built in
morphine
If brain is flooded with opiates, such as
heroin and morphine, the brain may stop
producing these natural opiates and physical
addiction and withdrawal will result
Released in response to pain or
vigorous exercise
This is the neurotransmitter responsible for
allowing bears and other animals to
hibernate. Heroin slows heart rate,
respiration, and metabolism in general…
exactly what you would need to hibernate…
if you were a bear. Heroin can lead to death
by shutting down the CNS permanently.
Purpose: Pain control
Structurally similar to heroin and has
similar functions: pain reduction,
pleasure
Opiates (such as heroin, morphine)
work by attaching at endorphin
receptor sites = AGONISTS