Mechanisms of LSD :: Biology Essays Research Papers

Mechanisms of LSD: a Glimpse into the Serotonergic System In 1938, Albert Hoffman discovered, invented a substance that would revolutionize the American drug culture forever and would change how we, as psychologists and biologists, thought about psychosis. That substance was LSD. A simple molecule, LSD has the potency that no other drug has. Only a drop will produce the desired hallucinations and euphoria. In addition, it does not seem to be physically addicting, although tolerance to the drug can develop in as few as three days but disappears after week of abstinence. Much 'research' has been done into the actual effects of the drug. LSD most profound effect on behavior is the production of sensory distortions, such as hallucinations, and euphoria. It also produces dilated pupils, increased blood pressure, and increased heart rate (7, 9). However, little is know about the mechanisms by which it acts. It is known that LSD affects the serotonergic system in the brain. However, the actual ways in which it acts on that system to modify behavior remains unclear. Before we explore the current research into LSD, it may be helpful to review some of the ways in which serotonin affects behavior. Serotonin (also called 5-HT) is a neurotransmitter that is produced from tryptophan. Although serotonin is only produced by a small number of neurons (1000's), each of those neurons innervates as many as 500,000 other neurons (3,12). For the most part, these neurons originate in the Locus Coerleus (LC) and the Raphe Nuclei (RN) (12). The LC controls the release of n orepinephrine, a neurotransmitter/hormone that regulates the sympathetic NS. It also has neurons that extend into the cerebellum, thalamus, hypothalamus, cerebral cortex, and hippocampus (12). The RN extends its projections into the brainstem and up into the brain (12). It has been suggested that neurons in this region of the brain may be responsible for the inhibition of sensation, thus "protecting the brain from sensory overload." (12) The fact that these two regions innervate virtually every part of the brain shows that serotonin can activate large portions of the brain from a relatively small area of origination. Serotonin seems to have an inhibitory effect on these neurons (1, 12). Thus, it would decrease the occurrence and frequency of action potentials in the neurons that it innervates. Because of this, it produces neural activity (of lack of activity) that are in some way an inhibition of behavior. Mechanisms of LSD :: Biology Essays Research Papers Mechanisms of LSD: a Glimpse into the Serotonergic System In 1938, Albert Hoffman discovered, invented a substance that would revolutionize the American drug culture forever and would change how we, as psychologists and biologists, thought about psychosis. That substance was LSD. A simple molecule, LSD has the potency that no other drug has. Only a drop will produce the desired hallucinations and euphoria. In addition, it does not seem to be physically addicting, although tolerance to the drug can develop in as few as three days but disappears after week of abstinence. Much 'research' has been done into the actual effects of the drug. LSD most profound effect on behavior is the production of sensory distortions, such as hallucinations, and euphoria. It also produces dilated pupils, increased blood pressure, and increased heart rate (7, 9). However, little is know about the mechanisms by which it acts. It is known that LSD affects the serotonergic system in the brain. However, the actual ways in which it acts on that system to modify behavior remains unclear. Before we explore the current research into LSD, it may be helpful to review some of the ways in which serotonin affects behavior. Serotonin (also called 5-HT) is a neurotransmitter that is produced from tryptophan. Although serotonin is only produced by a small number of neurons (1000's), each of those neurons innervates as many as 500,000 other neurons (3,12). For the most part, these neurons originate in the Locus Coerleus (LC) and the Raphe Nuclei (RN) (12). The LC controls the release of n orepinephrine, a neurotransmitter/hormone that regulates the sympathetic NS. It also has neurons that extend into the cerebellum, thalamus, hypothalamus, cerebral cortex, and hippocampus (12). The RN extends its projections into the brainstem and up into the brain (12). It has been suggested that neurons in this region of the brain may be responsible for the inhibition of sensation, thus "protecting the brain from sensory overload." (12) The fact that these two regions innervate virtually every part of the brain shows that serotonin can activate large portions of the brain from a relatively small area of origination. Serotonin seems to have an inhibitory effect on these neurons (1, 12). Thus, it would decrease the occurrence and frequency of action potentials in the neurons that it innervates. Because of this, it produces neural activity (of lack of activity) that are in some way an inhibition of behavior.