Until 1920, the action at a synapse was thought to be electrical. Otto Loewi, a German physiologist, aroused from sleep, with an idea to demonstrate the action at a synapse is chemical. He did so by taking fluid from one frogs’ heart and transferred it to another frogs’ heart to find that the heart rate increased. He also did this with another fluid, which decreased the heart rate. From this, he concluded that nerves send messages by releasing chemicals. These chemicals are the neurotransmitters that are synthesized by neurons, which are derived from the foods we eat. The neuron then transports them to axon terminals. From there, an action potential causes their release from the terminals. Once released, they attach to receptors and alter the activity of the postsynaptic neuron. When the molecules are separated form the receptors, they may become inactive chemicals. They may be taken back into the presynaptic terminal to be used again, also known as reuptake. Some empty vesicles return to the cell body to pick up a neurotransmitter (54-55).There are five different types of neurotransmitters: amino acids, peptides, acetylcholine, monoamines, purines, and gases. Serotonin falls into the monoamines, which are defined as “non-acidic neurotransmitters containing an amine group (NH2), formed by a metabolic change of certain amino acids” (56). Serotonin plays a part in some drug effects, attack behaviors, depression, eating regulation, learning, sleep, and PMS.HallucinogensSome hallucinogens, including LSD, DMT, psilocin, and psilocybin, inhibit the release of serotonin. They act as false transmitters, by attaching to the postsynaptic receptor sites and not allowing serotonergic activity. No one really understands how these drugs produce such profound changes in mental functioning. “One speculation of how they manifest their alterations of mood, perception, and thought is that the pontine raphe,...
