Chemistry of EmotionsEmotions are part of everyday life and they have different meanings to different people. They were first studied by Charles Darwin in 1872, he suggested that emotions developed and adapted over time. He wanted to prove that humans and animals had the same emotions so he observed not only their facial expressions, but also their behavior. Charles Darwin and ,a physician, Guillaunme-Benjamin- Amand Duchenne concluded that face expressions worked together to show a few emotions. Duchenne applied electrical current to the faces of his volunteers, by imitating the right combination of facial expressions, he produced more than 60 photographic plates that he believed were emotions. Darwin however disagreed with this, he believed that not all of Duchenne’s slides showed human expressions. To prove his theory, he invited guests and presented 11 of Duchenne’s slides, he asked his guests to guess the emotion of every slide. The guests united and agreed about certain emotions -like sadness, fear, happiness, and surprise- but disagreed about what other slides showed. Darwin then used these results and his own understanding of emotions to write “Expression”. Emotions consist of not only physical components, but also chemical components. The most important chemical neurotransmitters that control emotions are: Dopamine (C8H11NO2), Norepinephrine (C8H11NO3), Serotonin (C10H12N2O), Glutamic acid (C5H9NO4), and GABA (C4H9NO2). Neurotransmitters impact mood and emotions, it has a connection to health, genetic factors, environmental factors, external emotional stimulus, and nutrition. Dopamine (C8H11NO2) plays a big role in controlling positive emotions, it also contributes to the creating and storing memories. Dopamine is produced in several parts in the brain, including the ventral tegmental area (located near the midline floor of the midbrain) and the substantia nigra (a basal gangliain the midbrain). It sends signals from the central nervous system and allows information to be passed between one neuro to another. Too much dopamine can cause schizophrenia and bipolar disorder, but too little of it can cause social phobia, depression, Parkinson’s Disease, and ADHD.  Norepinephrine (C8H11NO3) role is to mobilize the brain and body for action, it enhances alertness, focus of attention, and retrieval of memory, but it also increases restlessness and anxiety. Low levels of it can cause ADHD, low blood pressure, depression, and stress. Serotonin (C10H12N2O) regulates signals between nerve cells, it plays a big role in the central nervous system. It is known for its major part in mood, happiness and anxiety. The serotonin that is used in the brain must be produced inside it. Glutamic acid (C5H9NO4) influences many areas of the brain, but before it can act it must be attached to a NMDA receptor which helps regulate number of sodium, calcium, and magnesium ions that enter and exit the cells. It is essential for normal healthy brain function, it can be used to treat many disorders like schizophrenia, Parkinson’s Disease, muscular dystrophy. GABA (C4H9NO2) serves to control fear or anxiety, it is a chemical messenger in the brain. Low GABA can cause agitation, trouble relaxing, panic disorders, etc. These neurotransmitters along with hormones are involved in feeling emotions. Many chemical reactions take place in the brain because of synapses which through these neurons transmit messages using the neurotransmitters. The limbic system it’s made up of three structures, hippocampus, hypothalamus, and the amygdala. The hippocampus contains our long term memories, the hypothalamus controls hormones that are associated with survival and moods, and the amygdala connects emotional significance to memories and events. All these help with recognizing, controlling, and showing emotions. The hypothalamus takes control of our bodies, its chemical connection to the pituitary gland sends instructions to release hormones that regulate growth and metabolism.