PSY290H5 Chapter Notes - Chapter 4: Cholinergic, Aromatic L-Amino Acid Decarboxylase, Neurotransmitter
Document Summary
Ronald siegal (1989) has suggested that early humans learned to identify drugs by observing the reactions to various plants by their animals. Most psychoactive substances produce their behavioural effects by interacting with the existing chemistry of the nervous system. Neurotransmitter a chemical messenger that communicates across a synapse. Neuromodulator a chemical messenger that communicates with target cells more distant than the synapse by diffusing away from the point of release. Neurohormone a chemical messenger that communicates with target cells at great distance, often by travelling through the circulation: often travel in the blood supply to reach their final targets. Lo2: summarize the major criteria for identifying a substance as a neurotransmitter. Neurotransmitters are substances released by one cell at a synapse that produce a reaction in a target cell. Neuroscientists generally agree with the following additional criteria: a neurotransmitters must be synthesized within the neuron.
