This presentation summarizes key information about four major neurotransmitters: dopamine, GABA, glutamate, and glycine. It describes how each neurotransmitter is synthesized, the receptors it acts on, its functions in the brain and body, and potential implications when levels are too high or low. Dopamine is involved in reward and motor control and impacts conditions like Parkinson's and schizophrenia. GABA is the main inhibitory neurotransmitter and prevents overexcitement. Glutamate is the primary excitatory neurotransmitter influencing cognition and memory. Glycine also acts as an inhibitory neurotransmitter and is used in various biosynthesis pathways. References are provided at the end to cite sources of information.