Acetylcholine
A neurotransmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in many organisms. It is presented in autonomic nervous system (ANS) and in the motor division of the somatic nervous system. It is believed to be involved in memory, mood and learning.
Seretoin
A monoamine neurotransmitter presented in pineal gland, blood platelets, the digestive tract, and certral nervous system of human (CNS). It is used to alter mood of a person or treat depression. Also refered to as Happiness Hormone.
Endorphins (endogenous morrphine)
A neurotransmitter produced by pituitary gland and hypothalamus in vertebrates during exercise, excitement, pain, love, etc.
It act as a pain killer. Immediately after injury, endorphins allow animals to feel a sense of power and control over themselves that allows them to persist with activity for an extended time.
Norepinephrine
A nerotransmitter affect part of the brain where attention and responding actions are controlled. The brain also increases its stimulation on norepinephrine when stress is signaled.