Alpha & Beta-adrenergic blocker: Also known as "beta-blockers," these drugs reduce symptoms connected with hypertension, heart muscle problems, migraine headaches, and other disorders related to the sympathetic nervous system by competing with the nerve-stimulating hormone epinephrine for beta-adrenergic receptor sites located primarily in the heart, lungs, kidneys, and blood vessels. These beta-receptors enhance cardiac muscle contraction and smooth muscle relaxation in tissues; thus, blockers interfere with the action of epinephrine (which is used by the body to prepare for fight or flight), decreasing the body's reaction to stressful or fearful situations. Beta-blockers are sometimes used as anti-anxiety drugs, especially for stage fright; however, people taking a beta-blocker must avoid caffeine, alcohol, and salty foods, because the interaction of those substances and the drugs can raise the heart rate and blood pressure.
Amygdala: A structure of the interior of the rostral temporal lobe and part of the limbic system.
Autonomic Nervous System: The part of the peripheral nervous system that is automatic and voluntary.
Benzodiazepine: This is an anti-anxiety drug. Sometimes prescribed to chronic nightmare suffers.
Central Nervous System(CNS): The brain and spinal cord
Dopamine, norepinephrine, and serotonin: These are types of neurotransmitters that are classified as monoamines, due to their chemical structure. These neurotransmitters modulate the function of widespread regions of the brain, increasing or decreasing the activities of particular brain functions.
DSM-IV (or just DSM): The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. This book, published by the American Psychiatric Association, attempts to classify all known psychological disorders according to symptoms. It is generally used by psychiatrists to determine diagnoses of patients, and to determine what does or does not constitute a mental disorder.
EEG: An ElectroEncephaloGram is a recording of electrical potentials from the brain through surface electrodes placed on the scalp. By observing abnormalities in recordings and determining the area of the brain from which they originate, the physician's ability to diagnose and treat such conditions as epilepsy, cerebral tumor, encephalitis, and stroke, is greatly enhanced. Due to the non-invasive nature of the procedure, this is also one of the most common ways to monitor transitions between the various stages of sleep in humans.
Epinephrine: A natural chemical involved in the fight-flight-frights syndrome
Fat-solubility: Fat solubility is a descriptive term meaning that the substance referred to can dissolve in fat and (usually) does not dissolve in water.
Forebrain: The most forward section of the brain. This area is responsible for emotions, thought process, self-awareness, memory, and motor movement.
Hippocampus: A forebrain structure of the temporal lobe, constituting an important part of the limbic system. Includes the hippocampus proper, dentate gyrus, and subiculum.
L-DOPA: This is a drug used to alleviate some of the symptoms of Parkinson's disease (see below), particularly trembling, rigidity, and slow movements; the drug is also called levodopa. Parkinson's disease results when the concentration of dopamine in the brain is depleted. L-dopa enters the brain through the bloodstream more easily than dopamine itself, and is there converted into dopamine. Virtually all patients on l-dopa experience some side effects, which may include nausea, loss of appetite, cardiac irregularities, and psychological changes.
Melatonin: This is a substance that is synthesized in the pineal gland (a pea-like organ located in the brain which is sensitive to different levels of light and is essential to the functioning of an animals biological clock). The pineal gland halts the synthesis of melatonin when light hits the retina of the eye. Besides influencing daily, or circadian, rhythms such those of sleep and temperature, the pineal gland and melatonin appear to direct annual rhythms and seasonal changes in animals.
Norepinephrine: A neurotransmitter found in the brain and in the sympathetic division of the autonomic nervous system.
Parasomnia: From "para-" (around) and "somnia" (sleep), this is a type of disorder characterized by abnormal behavioral or physiological events occurring in association with sleep, specific sleep stages, or sleep-wake transitions. Parasomnias listed in the DSM-IV include Nightmare Disorder, Sleep Terror Disorder, Sleepwalking Disorder, and Parasomnia Not Otherwise Specified. (DSM-IV; American Psychiatric Association, 1994, p.579).
Parkinsons Disease: A degenerative brain disorder first described by the English surgeon James Parkinson in 1817, in which the chemicals that facilitate electrical transmission between nerve cells are depleted. Symptoms usually begin after age 40 with trembling of the lips and hands, loss of facial expression, and muscular rigidity. As it progresses it may bring on body tremors, particularly in muscles at rest, movements may become slow and difficult, and walking degrades to a shuffle. After many years physical incapacity may occur. Dementia occurs in at least 50% of the patients; depression is also common. It was the first disease to be treated by drugs that replace deficient neurotransmitters. When drugs such as L-Dopa (see above) are taken orally, many of the worst symptoms are lessened.Future approaches to treatment include a focus on early detection and slowing progression of the disease. Encouraging results have been reported from surgical insertion of a pacemaker-like device deep in the brain to suppress uncontrolled movements, but surgical transplantation of fetal dopamine-producing cells failed to show significant benefits in a controlled study. Traditional surgery can alleviate some tremors, and physical therapy may also help mobility.
Parkinsonism: a descriptive term meaning having the characteristics of Parkinson's disease (see below), but usually not referring to the disease itself. Parkinsonism may be caused by head injury, encephalitis, syphilis, carbon monoxide poisoning, cerebral arteriosclerosis, use of MPTP (a synthetic narcotic), or other diseases or conditions.
Psychosis: This is broad category of mental disorder encompassing the most serious emotional disturbances, often rendering the individual incapable of staying in contact with reality. Symptoms of these disorders may include: hallucinations and delusions, severe deviations of mood (depression and mania), lack of, or inappropriateness of, emotional response, and severe impairment of judgment. Other types of psychosis involve brief episodes, characterized by an acute onset lasting no longer than a month, usually resulting from situational circumstances such as an earthquake or flood. Non-specified psychotic disorders include psychotic symptoms, e.g., delusions, hallucinations, or disorganized behavior, that cannot be classified in any other disorder. Organic psychoses, so called because of the structural deterioration of the brain, include senile dementia and Alzheimer's disease; occurring in middle to old age, these disorders involve progressive, nonreversible brain damage. Organic brain damage may also result from toxic reactions to such substances as alcohol, PCP, amphetamines, and crack cocaine.
REM-Stage Sleep: The Rapid Eye Movement stage of sleep is characterized by (you guessed it!) rapid darting movements of the eyes, as if surveying a scene, as well as complete paralysis of the rest of the body. This is the stage in which dreams typically occur, and if a person is awakened during this stage of sleep, they will usually report having been dreaming, and be able to describe these dreams in some detail.
Reserpine: This is an active ingredient isolated from the root of the snakeroot plant (Rauwolfia serpentina), a small evergreen climbing shrub of the Dogbane family native to the Indian subcontinent. Known in India as Sarpaganda, it was used for centuries to treat insanity as well as physical illnesses such as fevers and snakebites. After its isolation in 1952 it was used to lower high blood pressure, but its property of producing severe depression as a side effect also made it useful in psychiatry as a tranquilizer in the control of agitated psychotic patients. It has largely been replaced in psychiatric use by the phenothiazine tranquilizers, although it is still used as an experimental tool in the study of psychosis. Reserpine causes many toxic side effects including nightmares, Parkinsonism (see above), and gastrointestinal disturbances.
Schizophrenia: A serious mental disorder characterized by disordered thoughts, delusions, hallucinations, and often bizarre behaviors.
Slow-wave Sleep: Stages 3 and 4 of the sleep cycle, these are characterized by long, slow, synchronous brainwave activity. A person is typically difficult to wake from slow-wave sleep, and if they are awakened they will usually be groggy and disoriented, and will not recall any dreams. Parasomnias involving movement, such as sleepwalking (somnambulism) and Sleep Terror Disorder, typically occur during slow-wave sleep.
Sympathetic Nervous System: A branch of the autonomic nervous system that releases adrenaline.