Ablation experiment

-- an attempt to determine the behavioral changes that follow brain damage


Acetaldehyde

-- a toxic metabolite of ethyl alcohol


Acetaldehyde dehydrogenase

-- an enzyme that rapidly converts acetaldehyde into harmless acetic acid


Acetylcholine

-- a neurotransmitter of the autonomic, somatic, and central nervous systems


Acetylcholinesterase

-- an enzyme that rapidly inactivates acetylcholine that has been released at the synapse


Acetylcholinesterase inhibitor

-- a drug that blocks acetylcholinesterase, thereby increasing levels of acetylcholine in the synapse


Acquired motivation

-- in this context


ACTH

-- a pituitary hormone (adrenocorticotropic hormone) that stimulates the release of hormones from the adrenal cortex during stress


Action potential

-- the electrical activity that carries information down the neuron


Active transport

-- a metabolic process that can transfer relatively large molecules across a cell membrane


Acupuncture

-- a procedure to produce pain reduction by the mechanical stimulation of nerves


Adenyl cyclase

-- a compound that serves as a second messenger to initiate neuromodulatory changes


Affective contrast

-- an opponent emotion produced by the removal of a relatively novel emotion-inducing stimulus


Affective habituation

-- a reduced emotional response to a familiar emotion-inducing stimulus


Affective withdrawal

-- a strong opponent emotion produced by the removal of a familiar emotion-inducing stimulus


Agonist

-- a drug that mimics the effect of a neurotransmitter


Alcohol

-- a central nervous system depressant that is produced by fermentation


Allergy

-- an abnormally strong response of the immune system to a harmless foreign substance


Alpha methyl tyrosine

-- an inhibitor of the enzyme tyrosine hydroxylase


Alpha receptor

-- a specific receptor type for norepinephrine and related compounds


Alpha wave

-- a regular EEG pattern that accompanies quiet resting in the absence of visual stimulation


Alzheimer's disease

-- a degenerative disorder of brain acetylcholine systems that can accompany senescence


Amphetamine

-- a central nervous system stimulant that acts on neurons that release dopamine or norepinephrine


Amphetamine psychosis

-- the symptoms of psychotic behavior that can accompany an overdose of amphetamine


Analgesic

-- a drug that reduces pain


Anaphylactic shock

-- a severe allergic response that can result in respiratory collapse and death


Anesthetic

-- a drug that causes the loss of sensation


Anion

-- a negatively charged ion (e.g., Cl-)


Antagonist

-- a drug that blocks the action of a neurotransmitter


Anterior cortex

-- a portion of the cerebral cortex that is a target area for the fibers of the MFB reward system


Antibodies

-- chemically specific molecules that are produced by B cells during the humoral immune response


Anticholinergics

-- drugs that specifically interfere with the activity of neurons that release acetylcholine


Antigen

-- a foreign body that induces the formation of antibodies


Antihistamine

-- a drug that interferes with the effects of histamine on cells


ARAS

-- the ascending reticular activating system; a brain system that mediates arousal


Arcuate nucleus

-- a hypothalamic nucleus that releases opiate transmitters in the limbic system


Area postrema

-- a specialized brain structure that lies outside the blood-brain barrier and controls the vomiting reflex


Astrocytes

-- specialized glial cells that comprise a part of the blood-brain barrier


Atropine

-- an extract from the nightshade plant (Atropos belladonna) which blocks muscarinic receptors for acetylcholine


Attention deficit disorder

-- a disorder that is characterized by excessive activity


Autism

-- a severe disorder that is characterized by language deficits, learning disabilities, and abnormal responses to external stimuli


Autoimmune diseases

-- disorders that are caused by an inappropriate attack by the immune system on the body's own proteins


Autonomic nervous system

-- the portion of the peripheral nervous system that regulates the visceral organs, glands, and circulatory system


Autoreceptors

-- receptors on the presynaptic neuron that modulate activity by responding its to own neurotransmitter


Avoidance learning

-- a learned response to a signal that predicts the occurrence of an aversive stimulus


B cell

-- a specialized white blood cell that is formed in the bone marrow and participates in the humoral immune response


Barbiturate

-- a drug that depresses central nervous system activity


Behavioral inhibition

-- the withholding of previously rewarded responses that would now lead to nonreward or punishment


Behavioral pharmacology

-- the analysis of the effects of drugs on behavior


Behavioral tolerance

-- the reduced behavioral response to a drug that occurs as a result practice


Benzodiazepines

-- a chemical class of drugs (e.g., Librium and Valium) that typically have antianxiety effects


Beta-lipotropin

-- a pituitary hormone incorporating several of the same sequences of amino acids that comprise peptides that are known to be important in the stress response


Beta receptor

-- a specific receptor for epinephrine, norepinephrine, and related compounds


Biochemical marker

-- a specific metabolite of a neurotransmitter system that can be correlated with a specific disorder


Biosynthesis

-- the production of neurotransmitters by the neuron


Bipolar depression

-- a disorder that is characterized by episodes of manic behavior that are followed by severe depression


Blood brain barrier

-- a mechanical and lipid barrier that limits the ability of many types of molecules from reaching the neurons of the brain


Body surface

-- includes the skin, mucous membranes, and lungs as surfaces through which drugs may enter or exit the body


Bright pain

-- acute, sharp pain that occurs in response to an aversive stimulus such as a pin prick


Caffeine

-- a naturally occurring xanthine derivative that acts as a central nervous system stimulant


Calcium (Ca++) channels

-- membrane pores that determine Ca++ permeability, thereby regulating membrane excitability


Carbachol

-- an acetylcholine mimicker that is not inactivated by acetylcholinesterase


Catecholamines

-- a chemical class of compounds that includes epinephrine, norepinephrine, and dopamine


Cation

-- a positively charged ion (e.g., Na+ or Ca++)


Cellular response

-- an immune response that is characterized by the proliferation of T cells


CER

-- a conditioned emotional response, to a signal that predicts aversive consequences, which suppresses ongoing behavior


Cerebrospinal fluid

-- the clear filtrate of the blood that bathes and cushions the neurons of the brain and spinal cord


Chemical degradation

-- the inactivation of neurotransmitters (or drugs) by specific enzymes


Chemical transmission

-- the transfer of information from one cell to another through the release of a chemical messenger


Chloride (Cl-) channels

-- membrane pores that determine Cl- permeability, thereby regulating membrane excitability


Chlorpromazine

-- a drug that stabilizes the autonomic nervous system during stress and is effective in reducing psychotic symptoms, probably by blocking dopamine receptors


Cholinomimetics

-- a class of compounds that mimic the actions of acetylcholine


Choroid plexus

-- specialized blood vessels in the brain ventricles that produce cerebrospinal fluid


Cimetidine

-- a drug (Tagamet) used in the treatment of gastric ulcers to specifically block the H2 receptors for histamine and to reduce the release of gastric acid


Circadian rhythm

-- the daily cyclic fluctuations of the body's physiological systems


Circumventricular organs

-- a specialized group of brain structures that lie outside the blood-brain barrier allowing them to monitor changes in body conditions


Clinical potency

-- the typical drug dosage that therapists use to get the desired drug effect


Cocaine

-- a drug that can serve as a local anesthetic and a powerful central nervous system stimulant, probably through interference with the reuptake of dopamine and norepinephrine


Codeine

-- a narcotic drug that is one of the components of opium


Compensatory response

-- a physiological or behavioral response that opposes the direct effects of a drug or environmental stimulus


Competitive inhibition

-- the competition of drug molecules with the neurotransmitter molecules for access to the receptor site


COMT

-- an extracellular enzyme, catecholamine O-methyl transferase, that participates in the breakdown of catecholamines


Conditioned fear

-- the response to a signal that has been paired with an aversive stimulus


Conflict

-- the response to a situation in which behavior that normally has a desirable outcome may sometimes be punished


Contingency

-- a predictable relationship between a specific response and some change in the environment


Cortisol

-- a hormone released by the adrenal cortex, especially in response to stress


CR

-- in Pavlovian conditioning, the conditioned response to a signal that reliably predicts the occurrence of a biologically important event


Cross-tolerance

-- the reduced response to a drug due to exposure to some other drug


CS

-- in Pavlovian conditioning, the signal that reliably predicts the occurrence of a biologically important event


Curare

-- a drug that causes muscular paralysis by blocking the action of acetylcholine at the nerve-muscle junction


Cyclic AMP

-- a compound that serves as a second messenger to initiate neuromodulatory changes


D1 and D2 receptors

-- two receptor types for dopamine


DBH model

-- Stein and Wise's biological model that proposes reduced dopamine beta hydroxylase as a possible cause of schizophrenia


Delay conditioning

-- in Pavlovian conditioning, a procedure in which a signal is accompanied, after a brief delay, by a biologically important event


Delirium tremens

-- a progressive dysfunction of the motor system that occurs in response to long-term alcohol consumption


Delta wave

-- the characteristic slow-wave EEG pattern that accompanies periods of deep sleep


Denervation supersensitivity

-- an exaggerated sensitivity of neurons to a neurotransmitter following the destruction of presynaptic neurons


2-deoxy glucose

-- a compound (similar to glucose) that can be radioactively labeled to assess the metabolic activity of different brain areas


Depolarize

-- to reduce the electrical potential across the membrane of the neuron


Dexamethasone suppression test

-- a measurement of the ability of dexamethasone (a synthetic cortisol) to suppress cortisol production which has been useful in the diagnosis of depression


DHPG

-- a metabolite (3,4-dihydroxyphenethylene glycol) of catecholamines that may serve as a biochemical marker for certain types of depression


Diffusion

-- the random movement of ions or other particles toward a uniform distribution or concentration (e.g., across the neuronal membrane)


Digitalis

-- an extract from the foxglove plant (Digitalis purpura) which acts as an autonomic nervous system stimulant


Disulfiram

-- a drug that interferes with the enzyme acetaldehyde dehydrogenase, thus causing illness following alcohol ingestion


Dopamine

-- one of the catecholamines, a neurotransmitter of the central nervous system, and a hormone of the adrenal medulla


Dose-response curve

-- the relationship between different dosages of a drug and the accompanying changes in physiology or behavior


Drug

-- a chemical compound (natural or synthetic) that is administered for its specific effects


Drug action

-- the biochemical effect of a drug on the neuron, especially at the synapse


Drug effect

-- the end result of a drug's action that is reflected by a change in physiology or behavior


Dull pain

-- the long-term, throbbing sensation of pain


Dynamic synapse

-- the concept of the synapse as a system that undergoes constant change through the regulation of transmitter release, number of receptors, and so forth


E

-- (see Epinephrine)


ED-50

-- the amount of drug that serves as an effective dose for 50 percent of the population


Electroconvulsive therapy

-- a procedure, frequently used in the treatment of depression, that involves the passage of electric current through the brain to induce seizure activity


Emergence

-- the appearance of specific behavioral abilities in concert with the maturation of specific brain systems


Encephalization

-- the pattern of brain maturation from lower to progressively higher regions


Endorphins

-- the term applied to a group of endogenous peptides that are involved in pain reduction


Enkephalins

-- the term applied to the two small peptides that were the first morphine-like substances discovered in animals


Enzyme induction

-- the increased production of an enzyme that occurs as a result of exposure to the substrate


Ephedrine

-- a drug that acts indirectly by causing the release of norepinephrine from the neuron


Epinephrine

-- one of the catecholamines, the principle hormone of the adrenal medulla that is released during certain types of stress; also known as adrenaline


Ergot

-- a grain fungus that is a stimulant of the sympathetic nervous system


Escape learning

-- the acquisition of a response that terminates an aversive stimulus


Experimental extinction

-- in Pavlovian conditioning, the repeated presentation of a CS that had previously signaled a biologically important event (the US)


Extrapyramidal motor system

-- one of the systems of the brain responsible for body movement


False transmitter (+/-)

-- a substance that can be stored in a neuron and released by neural activity; the compound may enhance (+) or interfere with (-) normal neurotransmitter activity


Flight-or-fight response

-- a sympathetic nervous system response that prepares an organism to cope with a stressful event


Flinch/jump test

-- a procedure to measure the pain threshold


Free operant (Sidman) avoidance

-- an unsignaled avoidance training procedure in which each response postpones the delivery of the next shock


GABA

-- an inhibitory neurotransmitter (gamma amino butyric acid) that is abundant throughout the brain


GABA receptor complex

-- a receptor structure with separate sites for GABA, sedative/convulsants, and benzodiazepines that regulates Cl- channels


Ganglionic stimulation

-- the excitation of the autonomic nervous system ganglia via chemical or electrical stimulation


General adaptation syndrome

-- the sequence of physiological responses to stress as described by Hans Selye


Generalized fear

-- the spreading of a conditioned fear response from the initial, specific CS to other situations


Glycine

-- an amino acid that is also a neurotransmitter (usually inhibitory) in the spinal cord and brain


H1 receptor

-- a type of histamine receptor that mediates responses to injury or allergies throughout the body


H2 receptor

-- a type of histamine receptor that mediates the release of gastric acid from the stomach


Half-life

-- the amount of time required for half of the drug dosage to be inactivated or removed from the body


Haloperidol

-- a drug that blocks dopamine (D2) receptors and is commonly used in the treatment of schizophrenia


Heroin

-- a synthetic opiate drug


5-HIAA

-- a metabolite (5-hydroxy indole acetic acid) of serotonin that may serve as a biochemical marker in the diagnosis of suicidal depression


Hippocampal theta

-- a characteristic EEG pattern in the septohippocampal system that appears to be mediated by cholinergic neurons


Histamine

-- an amine compound that is present throughout the body, participating in responses to injury and immunological challenges


Hormones

-- naturally occurring compounds, released into the bloodstream by endocrine glands, that stimulate chemically specific receptors on target organs


Humoral response

-- an immune response that involves the production and release of specific antibodies by the B cells


HVA

-- a metabolite (homovanillic acid) of dopamine that may serve as a biochemical marker in the diagnosis of certain types of schizophrenia


Hyperkinesis

-- (see Attention deficit disorder)


Hypodermic syringe

-- a device for injecting drugs under the skin


Immunoglobulins

-- a set of five different types of antibodies, produced by B cells, which are probably involved in separate types of humoral immune responses


Inactivation

-- the rapid termination of the activity of a neurotransmitter to allow the postsynaptic cell to recover and be ready to initiate the next action potential


Indirect action

-- the action of drugs that have little or no effect on the postsynaptic receptors, but produce their effects by stimulating the release of the normal neurotransmitter


Inhalation procedure

-- the administration of drugs through the membrane surfaces of the lungs


Interstitial fluid

-- the extracellular fluid that bathes cells throughout the body


Intraarterial administration

-- the administration of a drug by injection directly into an artery


Intracerebral administration

-- the administration of a drug by injection or application directly into brain tissue


Intracisternal administration

-- the administration of a drug by injection directly into the cerebrospinal fluid


Intracranial administration

-- the administration of a drug locally into the brain, usually by the Intra cerebral or Intra cisternal route


Intramuscular administration

-- the administration of a drug by injection directly into a muscle


Intraperitoneal administration

-- the administration of a drug by injection through the abdominal wall into the space surrounding the viscera


Intrathecal administration

-- the administration of a drug (typically an anesthetic) by injection through the spinal sheath into the local region surrounding the spinal cord


Intravenous administration

-- the administration of a drug by injection directly into an vein


Iproniazid

-- a drug that inhibits the activity of the enzyme monoamine oxidase and is commonly used in the treatment of depression


Ischemia

-- the loss of blood (and oxygen) supply to an organ or portion of an organ


James-Lange theory

-- the theory that the expression of an emotion occurs before the experience of an emotion


L-DOPA

-- a precursor of dopamine and norepinephrine


Law of initial values

-- the principle that a drug effect depends on the initial level of the physiological or behavioral system


LD-50

-- the dosage of a drug that would be lethal to 50 percent of the population


Learned helplessness

-- the result, generalized to other situations, of learning that one's behavior is ineffective in changing the environment


Leukocytes

-- white blood cells that commonly participate in the body's response to injury or immunological challenges


Limbic system

-- a set of brain structures involved in emotional and motivational responses


Lipid soluble

-- the ability of a relatively large molecule to enter a cell by dissolving in the lipid (fat) membrane of the cell


Lithium

-- a simple salt that is commonly used in the treatment of manic behavior


Liver enzymes

-- in this context, enzymes formed by the liver that facilitate the breakdown of drugs


Locus coeruleus

-- the primary location of neurons that send axons through the MFB to release norepinephrine in the anterior cortex


Long delay conditioning

-- in Pavlovian conditioning, a procedure in which the CS is presented for a relatively long period of time before being accompanied by the US


LSD

-- a drug (lysergic acid diethylamide) that causes various forms of hallucinations


Lymphokines

-- compounds released by sensitized T cells in the cellular immune response


Macrophage

-- specialized white blood cells that engulf potential antigens and "present" them to B cells


MAO

-- an intracellular enzyme (monoamine oxidase) that converts catecholamines and serotonin into inactive forms


MAO inhibitor

-- a drug that inhibits the activity of MAO, allowing neurotransmitter levels to increase; commonly used in the treatment of depression


MAO isozymes

-- different forms of MAO that are present throughout the body (MAO-A) and in the brain (MAO-B)


Mast cells

-- large cells in connective tissues, respiratory tract, eyes, and lymph glands that participate in the humoral immune response


Mecholyl

-- a drug that mimics acetylcholine at muscarinic receptor sites


MED-50

-- minimum effective dose for 50 percent of the population


Melatonin

-- a hormone, released by the pineal gland, that participates in circadian rhythms


Membrane pores

-- interruptions in the cell membrane that allow small molecules to enter and exit the cell


Methyl atropine

-- a positively charged form of atropine that does not cross the blood-brain barrier


Methyl scopolamine

-- a positively charged form of scopolamine that does not cross the blood-brain barrier


MFB

-- a collection of fibers (the medial forebrain bundle) that projects through the hypothalamus to the anterior cortex and participates in the reward system


MHC

-- the template (major histocompatibility complex) in T cells that is used to determine self versus non-self


MHPG

-- a metabolite (3-methoxy-4 hydroxyphenylethylene glycol) of dopamine and norepinephrine that may be a biochemical marker for the diagnosis of depression


Mitogen

-- a compound that facilitates the proliferation of T cells


Morphine

-- a narcotic drug that is one of the components of opium


Mucous membranes

-- the smooth membranes lining the nose and mouth; some drugs can be readily administered through these membranes


Muscarine

-- a drug (derived from the mushroom Amanita muscaria) which mimics acetylcholine in the parasympathetic and central nervous systems


Muscarinic receptors

-- specific acetylcholine receptors (defined by their response to muscarine) that are present in the parasympathetic organs and in the central nervous system


Myasthenia gravis

-- a grave weakening of the muscles caused by a decrease in the acetylcholine receptors of the somatic muscles


Naloxone

-- a drug that blocks opiate receptor sites


Narcotic

-- a drug that causes a numbing of pain and other sensations


Negative afterimage

-- a perceptual illusion (usually of the visual system) which follows the termination of a strong stimulus


Nerve-Muscle junction

-- the region where alpha motor neurons release acetylcholine onto receptors in the muscles


Neurochemistry

-- the analysis of the response of neurons to drugs


Neuromodulation

-- relatively long-term changes in neuronal function (e.g., increase in transmitter or decrease in receptors) that occur in response to drugs, behavioral experience or other influences


Neuron doctrine

-- the notion that the brain is comprised of individual cells rather than a syncytium of protoplasm


Neuronal specificity

-- the similarity among brains in terms of anatomical pathways, neurochemistry, and other features of organization


Neurotoxin

-- a compound that leads to the impairment or destruction of neurons


Neurotransmitter

-- a compound that is stored in the terminal endings of neurons, released into the synapse by the arrival of an action potential, and bound with a specific receptor


Nicotine

-- a compound (present in tobacco) that mimics acetylcholine at receptors in the autonomic nervous system, the central nervous system, and the somatic muscles


Nicotinic receptors

-- specific acetylcholine receptors (defined by their response to nicotine) that are present in the autonomic ganglia, the somatic muscles, and at some central nervous system sites


Nigrostriatal pathway

-- fibers from cells of the substantia nigra that project to dopamine receptors in the striatum and comprise a major pathway of the extrapyramidal motor system


Noncompetitive inhibition

-- the antagonistic effect of drugs that alter the shape or structure of a receptor rather than mimicking a neurotransmitter


Nonspecific anxiety

-- a generalized feeling of fear or anxiety for which no specific cause can be identified by the individual


Norepinephrine

-- one of the catecholamines, a neurotransmitter of the sympathetic and central nervous systems, and a hormone of the adrenal medulla


6-OHDA

-- a neurotoxin (6-hydroxy dopamine) that destroys the terminal endings of cells that release dopamine or norepinephrine


Operant behavior

-- B. F. Skinner's descriptive and empirical system of the analysis of instrumental behavior


Opioid link

-- a short neuron in the spinal cord that relays pain inhibitory messages from descending serotonergic fibers by releasing opioid neurotransmitters that block incoming pain signals


Opium

-- a narcotic compound (derived from the opium poppy), that is comprised of morphine and codeine


Opponent process theory

-- Solomon and Corbit's theory that the termination of a situation that elicits a strong emotion will elicit an opponent emotion


Oral administration

-- the administration of drugs by ingestion through the mouth


Organismic variables

-- age, sex, body weight, and so forth can influence the size or direction of a drug effect


Parasympathetic

-- the division of the autonomic nervous system that is involved with vegetative processes; postganglionic fibers release acetylcholine


Parkinsonism

-- a progressive dysfunction of dopamine fibers in the extrapyramidal motor system


Pavlovian conditioning

-- the procedures, originally described by Pavlov, that allow the learning of relationships among environmental stimuli


Paw-lick test

-- a procedure to measure the pain threshold


PEA

-- an amphetamine-like compound that may serve as a biochemical marker in the diagnosis of certain types of schizophrenia


Pentylenetetrazol

-- a convulsant drug (Metrazol) that stimulates the nervous system by reducing the recovery time between action potentials


Peptides

-- short chains of amino acids, some of which serve as neurotransmitters


Periaqueductal gray

-- a collection of cell bodies in the brain stem that plays an important role in pain reduction


Pharmacological tolerance

-- physiological adjustments that reduce a drug's action following repeated exposures to the drug


Phenothiazines

-- a chemical class of drugs that is commonly used in the treatment of psychotic symptoms


Phencyclidine

-- a hallucinogen (PCP) that interferes with several different transmitter systems


Phenylketonuria

-- a disorder caused by the genetic absence of a single enzyme that disrupts the development of serotonergic neurons (among others)


Phosphoinositide cycle

-- a second messenger system that initiates neuromodulatory changes


Physical dependence

-- a drug-induced change in the body's physiology that necessitates the presence of the drug for normal function


Picrotoxin

-- a stimulant drug that acts on the GABA receptor complex to reduce Cl- permeability


Pineal gland

-- a brain structure that plays an important role in circadian rhythms


Pituitary

-- the master gland of the neuroendocrine system


Placebo

-- an inactive compound that may have an effect when it is administered as though it were a specific drug


Plasma compartment

-- the fluid portion of the blood


Pools

-- any of several locations (e.g., bladder or fat deposits) where a drug may be present in the body while having no effect


Postsynaptic neuron

-- the neuron that receives chemical messages from other neurons


Postsynaptic inhibition

-- the interference with chemical transmission by blocking or changing the shape of the receptors for the neurotransmitter


Pre-post design

-- a procedure for discriminating behavioral tolerance from pharmacological tolerance


Precursor

-- a compound that can be readily transformed into an active substance by the body


Preformed chemical mediators

-- a collection of compounds released by sensitized mast cells in the hay fever reaction


Presynaptic neuron

-- the neuron that sends messages to other neurons


Presynaptic inhibition

-- the interference with chemical transmission by blocking the action potential or the release of the neurotransmitter


Primary symptoms

-- the symptoms that are always present in a disorder and are useful in establishing a diagnosis


Proliferation

-- the rapid increase in the number of sensitized T cells during the cellular immune response


Protein binding

-- the attachment of a drug molecule to a large protein molecule which effectively inactivates the drug


Psychopharmacology

-- an analysis of the effects of drugs on mood, emotions, and other aspects of human behavior


Punishment

-- aversive events that are contingent upon the occurrence of a specific response


Raphe nucleus

-- a collection of serotonergic neurons in the brain stem that is involved in sleep


Rate-limiting enzyme

-- the enzyme that mediates the slowest step in a series of chemical reactions


Rebound effects

-- the behavioral effects, opposite to those produced by a drug, that occur when the drug is abruptly withdrawn


Receptor antibodies

-- substances produced by the immune system that destroy the body's own receptors


Receptor binding

-- the attachment of a drug to a receptor site; this drug/receptor complex can be isolated for study


Receptor sites

-- specific protein structures in the cell membrane that match the structure of the neurotransmitter molecule


Rectal administration

-- the administration of drugs through the membrane surfaces of the colon


Recurrent inhibition

-- a feedback loop in which the activity of a neuron inhibits further activity


REM sleep

-- a portion of the sleep cycle that is characterized by rapid eye movement, behavioral sleep, an "alert" EEG pattern, and dream reports


Renal excretion

-- the removal of a drug from the body through the action of the kidneys


Renshaw cell

-- a small neuron in the spinal cord that receives cholinergic input from motor nerves and releases glycine to produce recurrent inhibition


Reserpine

-- a drug which causes the gradual depletion of catecholamines and serotonin from neurons


Resting potential

-- the membrane potential (-70 millivolts inside) of an inactive neuron


Reticular formation

-- a diffuse net of small neurons in the brain stem that participates in the ascending arousal system


Reuptake

-- the inactivation of a neurotransmitter by transporting it back into the neuron that released it


Reward system

-- the brain structures (including the MFB, limbic system, and anterior cortex) that release catecholamines and mediate rewarded behavior


Ritualistic behavior

-- a regimen associated with the self-administration of a drug


Schizoaffective disorders

-- mental illnesses that are characterized by some of the same symptoms as schizophrenia


Schizophrenia

-- a severe psychotic disorder characterized by disordered thought processes, flattened affect, and withdrawal; usually associated with dopamine dysfunction


Scopolamine

-- a drug that blocks acetylcholine receptors in the parasympathetic and central nervous systems


Second messengers

-- compounds that initiate changes in neuronal function following the arrival of the neurotransmitter ("first" messenger)


Secondary reinforcer

-- a previously neutral stimulus that has rewarding properties as a result of its association with rewarding stimuli


Secondary symptoms

-- symptoms that may sometimes be present in a disorder, but are not consistent enough to be used for diagnosis


Self-administration

-- the voluntary administration of drugs that have rewarding properties


Semipermeable membranes

-- cell membranes having pores that allow small particles to pass through but restrict the passage of larger particles


Senescence

-- the stage of late adulthood


Sensitization

-- an exaggerated response to a drug because of prior exposure to that drug


Septohippocampal system

-- the local neuronal circuits between the septum and the hippocampus which release acetylcholine in the regulation of the hippocampal theta rhythm


Serotonin

-- a compound (5-hydroxytryptamine) that is common throughout the body, and also serves as a neurotransmitter in the central nervous system


Side effects

-- any unintended effect of a drug


Social defeat

-- a procedure to produce the experience of submission which can lead to neurochemical changes associated with the stress response


Sodium (Na+) channels

-- membrane pores along the axon which open to increase Na+ permeability during the propagation of the action potential


Sodium pump

-- an active transport system that regulates the resting potential by maintaining the high extracellular concentration of Na+


Spontaneous remission

-- the recovery from a disorder (e.g., depression) in the absence of treatment


Stage of alarm

-- the first stage of Selye's general adaptation syndrome, which initiates responses to the stressor


Stage of exhaustion

-- the final stage of Selye's general adaptation syndrome in which the organism's ability to counteract the stressor is depleted


Stage of resistance

-- the second stage of Selye's general adaptation syndrome in which the organism's physiological systems are actively combating the stressor


Storage pools

-- the regions within a neuron where neurotransmitter molecules are stored before becoming available for release


Structure-activity relationship

-- the correlation between chemical structure and drug effects


Strychnine

-- a stimulant drug that acts primarily by blocking the inhibitory effects of glycine receptors


Subcutaneous administration

-- the administration of drugs by injection under the skin


Substance abuse

-- the use of a drug or some other substance to an extent which interferes with work or family environments


Substance P

-- a peptide neurotransmitter that is released in the spinal cord by incoming pain fibers


Substantia nigra

-- a group of dopamine neurons that project to D2 receptors in the extrapyramidal motor system


Subtractive model

-- a method of analyzing structure/function relationships by determining which function is no longer present following the removal of a specific brain structure


Sudden death

-- death resulting from massive parasympathetic discharge that can be triggered by an acute stressor for which there is no obvious coping response


Suprachiasmatic nucleus

-- a structure of the hypothalamus that participates in circadian rhythms


Surgical shock

-- a generalized stress syndrome associated with surgical procedures


Sympathetic

-- the division of the autonomic nervous system that is involved with arousal processes; postganglionic fibers release norepinephrine


Sympathomimetic

-- drugs that mimic or otherwise increase the activity of neurotransmitters associated with the sympathetic nervous system


Synapse

-- the gap between successive neurons where chemical transmission takes place


Synaptic vesicle

-- small packets in the terminal endings of neurons where neurotransmitter molecules are stored for release


Syncytium

-- Golgi's notion that the nervous system was comprised of an interconnected net of protoplasm


T cell

-- a specialized white blood cell that is formed in the thymus gland and participates in the cellular immune response


Tachyphylaxis

-- rapid tolerance to the indirect actions of drugs


Tail-flick test

-- a test to determine the pain threshold


Tardive dyskinesia

-- an impairment of extrapyramidal motor system functions that eventually appears as a side effect of phenothiazines


Target organ

-- organs that have specific receptor sites for circulating hormones


Terminal endings

-- the final portion of the neuron that contains the mechanisms for the release of the neurotransmitter


Tetanus toxin

-- a substance that blocks the release of acetylcholine from alpha motor neurons


Tetrabenazine

-- a synthetic tranquilizer that produces effects similar to those of reserpine


Theobromine

-- a naturally occurring xanthine derivative that acts as a central nervous system stimulant


Theophylline

-- a naturally occurring xanthine derivative that acts as a central nervous system stimulant


Therapeutic ratio

-- the ratio of LD-50 to MED-50 that represents the clinical safety factor of a drug


Theta wave

-- a regular EEG pattern that accompanies the early stages of falling asleep


Think-drink effect

-- the observation that behavior is more closely related to perceived alcohol consumption than to actual consumption


Tolerance

-- a reduced response to a drug following repeated exposures to the drug


Trace conditioning

-- in Pavlovian conditioning, a procedure in which the CS is terminated for a brief period before the US is presented


Transdermal administration

-- the administration of a drug by application to the skin surface


Transpleural administration

-- the administration of a drug by injection into the space surrounding the lungs


Triad design

-- a procedure that involves the simultaneous testing of three groups: an untreated group, an experimental group, and a yoked control group


Tricyclic antidepressants

-- a chemical class of compounds that block the reuptake of catecholamines and are used in the treatment of depression


Two factor theory

-- the theory that avoidance behavior is based on a combination of Pavlovian and instrumental conditioning


Two way avoidance

-- an avoidance training procedure in which the signaled shock is presented alternately in either end of a shuttle box


Tyramine

-- a dietary amino acid; causes the "wine and cheese" effect during treatment with MAO inhibitors


Tyrosine hydroxylase

-- the rate-limiting enzyme in the synthesis of catecholamines


Ulcers

-- stomach lesions caused by excessive parasympathetic activity due to stress


UR

-- in Pavlovian conditioning, the reflexive response that is elicited by a biologically important event (the US)


US

-- in Pavlovian conditioning, a biologically important event (e.g., food powder or electric shock) that elicits a reflex (the UR)


Vagusstoff

-- Loewi's term for the chemical (acetylcholine) released by electrical stimulation of the vagus nerve


Vehicle

-- the carrier (usually a solution) mixed with the drug in order to facilitate its administration


Ventral tegmental area

-- a collection of neurons in the region of the pons that project axons through the MFB and release dopamine in the limbic system and anterior cortex


Withdrawal effects

-- symptoms (usually aversive) that accompany the abrupt cessation of drug use


Xanthines

-- a group of stimulant compounds (including caffeine, theobromine, and theophylline) that occur naturally in coffee, tea, chocolate and cola and act by increasing Ca++ permeability


Yerkes-Dodsen law

-- the inverted U-shaped relationship between arousal and performance


Yoked control

-- a procedure in which the environmental consequences for one subject are linked to the behavior of another subject