Neurotransmitters are chemical messengers that transmit signals between neurons. There are four main neurotransmitter systems: monoamines like dopamine and serotonin which regulate movement, mood, and reward; acetylcholine which is involved in memory, attention, and muscle control; amino acids like glutamate and GABA which are excitatory or inhibitory; and neuropeptides which modulate various functions. Disorders like Parkinson's, Alzheimer's, epilepsy, depression, and others have been linked to imbalances in specific neurotransmitters.

1. Neurotransmitters

2. Neurotransmitters
Four general neurotransmitter systems explain human behaviour:
• Monoamines:
- Catecholamine (Dopamine & Norepinephrine, Epinephrine)
- Indolamines (Serotonin [5 hydroxy tryptamine; 5-HT] )
• Acetylcholine
• Aminoacids (Glutamate, Aspartate, Glycine, GABA)
• Neuro-Peptides (Endorphines, Chole-cystokinine, Neurotensin)
• Soluble gases (Nitric oxide, Carbon Monoxide)
NEUROMODULATION

7. channels

9. Neurotransmitter
Example of Disorder Involving It
Neurotransmitter
Example of Disorder Involving It
Acetylcholine is a very widely distributed Alzheimer’s disease is associated with a lack
excitatory neurotransmitter that triggers of acetylcholine in certain regions of the
muscle contraction and stimulates the brain.
excretion of certain hormones. In the central
nervous system, it is involved in
wakefulness, attentiveness, anger, aggressio
n, sexuality, and thirst, among other things.
Dopamine is a neurotransmitter involved in The loss of dopamine in certain parts of the
controlling movement and posture. It also brain causes the muscle rigidity typical of
modulates mood and plays a central role Parkinson’s disease.
inpositive reinforcement anddependency.

10. GABA (gamma-aminobutyric acid) is an Some drugs that increase the level of
inhibitory neurotransmitter that is very GABA in the brain are used to treat
widely distributed in the neurons of the epilepsy and to calm the trembling of
cortex. GABA contributes to motor people suffering from Huntington’s
control, vision, and many other cortical disease.
functions. It also regulates anxiety.
Glutamate is a major excitatory It is also thought to be associated with
neurotransmitter that is associated Alzheimer’s disease, whose first
with learning and memory. symptoms include memory
malfunctions.
Norepinephrine is a neurotransmitter Norepinephrine plays a role in mood
that is important for attentiveness, disorders such as manic depression.
emotions, sleeping, dreaming, and
learning. Norepinephrine is also released
as a hormone into the blood, where it
causes blood vessels to contract and
heart rate to increase.
Serotonin contributes to various Depression, suicide, impulsive behaviour,
functions, such as regulating body and agressiveness all appear to involve
temperature, sleep, mood, appetite, and certain imbalances in serotonin.
pain.