2. Neurotransmitters
These are chemical messengers
that our body can't function
without. Their job is to carry
chemical signals (“messages”)
from one neuron (nerve cell)
to the next target cell. Nerve
cells send and receive
information from all body
sources. This constant
feedback is essential to our
body’s optimal function.
3. We have billions of nerve cells in your body. Nerve cells are generally made up of
three parts:
•A cell body.The cell body is vital to
producing neurotransmitters and
maintaining the function of the nerve
cell.
•An axon. The axon carries the electrical
signals along the nerve cell to the axon
terminal.
•An axon terminal.This is where the
electrical message is changed to a
chemical signal using neurotransmitters
to communicate with the next group of
nerve cells, muscle cells or organs.
4. Neurotransmitters are located in a part of the neuron called the
axon terminal. They’re stored within thin-walled sacs called
synaptic vesicles. Each vesicle can contain thousands of
neurotransmitter molecules. In this space, called the synaptic
junction, the neurotransmitters carry the message across less than
40 nanometers (nm) wide (by comparison, the width of a human
hair is about 75,000 nm).
Neurotransmitters are chemicals
that brain cells use to talk to each
other. Some neurotransmitters make
cells more active (called excitatory)
while others block or dampen a cell’s
activity (called inhibitory).
5. •Excitatory. Excitatory neurotransmitters “excite” the neuron and cause it to
“fire off the message,” meaning, the message continues to be passed along
to the next cell. Examples of excitatory neurotransmitters include glutamate,
epinephrine and norepinephrine.
Acetylcholine is also an excitatory
neurotransmitter because it
generally makes cells more excitable.
It governs muscle contractions and
causes glands to secrete hormones.
Alzheimer’s disease, which initially
affects memory formation, is
associated with a shortage of acetylcholine.
Glutamate is a major excitatory neurotransmitter. Too much
glutamate can kill or damage neurons and has been linked to
disease, stroke
6. •Inhibitory. Inhibitory neurotransmitters block or prevent
the chemical message from being passed along any
farther.Gamma-aminobutyric acid (GABA), glycine and
serotonin are examples of inhibitory NeuroTransmitters.
GABA (gamma-aminobutyric acid) is an inhibitory
neurotransmitter that helps
control muscle activity and
is an important part of the
visual system. Drugs that
increase GABA levels in the
brain are used to treat epileptic
seizures and tremors in patient
with Huntington’s disease.
7. Serotonin is a neurotransmitter that constricts blood vessels and brings on sleep. Low levels
of serotonin may cause sleep problems and depression, while too much serotonin can lead
to seizures.
Dopamine is an inhibitory neurotransmitter
involved in mood and the control of complex
movements. The loss of dopamine activity in
some portions of the brain leads
to the muscular rigidity of Parkinson’s disease.
Many medications used to treat behavioural
disorders work by modifying the action of
dopamine in the brain.
8. Modulatory.
Modulatory neurotransmitters influence the effects of other
chemical messengers. They “tweak” or adjust how cells
communicate at the synapse. They also affect a larger
number of neurons at the same time.
