Glossary

Synaptic release

An arriving action potential supplies the condition for calcium-channel opening. Calcium entry supports vesicle fusion and transmitter release.

• Synaptic release

Reversible receptor binding

Transmitter binds outside the ion pore; separate ions move through the gated channel. Binding is reversible.

• Reversible receptor binding

Signal termination

Diffusion, metabolism and reuptake are alternative or concurrent routes, not compulsory consecutive events for each molecule.

• Signal termination

Separate vesicular loading

Uptake ends in cytosol. A separate vesicular transporter loads a vesicle; the membrane transporter never becomes a vesicle.

• Separate vesicular loading

Receptor signaling mechanisms

Ionotropic receptors contain a ligand-gated channel. The modeled GPCR signals through separate intracellular machinery.

• Receptor signaling mechanisms

Receptor classification

Mechanism, location and effect are different dimensions. The course includes Trk as a non-GPCR metabotropic category.

• Receptor classification

Monoamine transport

Canonical course associations: DA–DAT, NE–NET and 5-HT–SERT. Uptake and vesicular loading are separate operations.

• Monoamine transport

Synaptic interface structure

Presynaptic/postsynaptic are relationships at a synapse. Release, uptake and vesicular loading use distinct structures.

• Synaptic interface structure

Drug and psychoactive terminology

Distinguish drug origin, psychoactive action, and naming without treating origin as a safety judgment.

• Drug and psychoactive terminology

Pharmacology, kinetics and dynamics

Separate questions about drug handling from questions about drug action and behavior.

• Pharmacology, kinetics and dynamics

Primary and secondary effects

Explain why primary and secondary effects depend partly on the purpose for which an effect is sought.

• Primary and secondary effects

Biopsychosocial context and differences

Use biological, psychological, and social factors together when explaining variation in drug effects.

• Biopsychosocial context and differences

History and reasoning about drug effects

Describe the deck’s historical arc and distinguish an effective intervention from evidence of an illness’s cause.

• History and reasoning about drug effects

CNS/PNS and brain regions

Orient major course brain regions within the CNS/PNS distinction and relate the emphasized regions to later transmitter pathways.

• CNS/PNS and brain regions

Neuron organization and relational terminology

Identify the principal neuron parts and apply pre/postsynaptic labels to a specific connection.

• Neuron organization and relational terminology

Action potentials

Describe the all-or-none action potential and distinguish its propagation from transmitter release at a terminal.

• Action potentials

Plasticity versus neurogenesis

Distinguish changing connections among neurons from producing new neurons.

• Plasticity versus neurogenesis

Glia

Explain how glial support and transmitter handling contribute to neuronal function.

• Glia

Precursors and acetylcholine

Trace acetylcholine synthesis, breakdown, and choline recycling, and locate the course’s cholinergic pathway examples.

• Precursors and acetylcholine

Dopamine families and pathways

Connect dopamine handling, D1/D2 receptor families, and the three named pathways without reducing dopamine to one behavioral label.

• Dopamine families and pathways

Norepinephrine and adrenergic receptors

Connect norepinephrine to its uptake transporter, receptor families, and central/peripheral course framing.

• Norepinephrine and adrenergic receptors

Serotonin and receptor exceptions

Identify serotonin’s transporter, precursor sequence, and ionotropic receptor exception while separating association from simple deficiency claims.

• Serotonin and receptor exceptions

Glutamate/NMDA and GABA comparisons

Compare glutamate and GABA receptor mechanisms and termination routes, including NMDA’s additional conditions.

• Glutamate/NMDA and GABA comparisons

Histamine, peptides and other messengers

Recognize the additional messenger groups at the limited depth provided by the course.

• Histamine, peptides and other messengers

Drug

An exogenous chemical that affects bodily processes, using the course definition.

• Drug and psychoactive terminology

Exogenous

Originating outside the body.

• Drug and psychoactive terminology

Endogenous

Produced within the body.

• Drug and psychoactive terminology

Psychoactive

Acting on the brain and potentially changing mood, behavior, or consciousness in the course framing.

• Drug and psychoactive terminology

Generic name

The name of a drug chemical, distinct from a marketed brand name.

• Drug and psychoactive terminology

Pharmacology

The study of drug action.

• Pharmacology, kinetics and dynamics

Pharmacokinetics

How the body affects a drug.

• Pharmacology, kinetics and dynamics

Pharmacodynamics

How a drug affects the body.

• Pharmacology, kinetics and dynamics

Psychopharmacology

The study of psychoactive drug effects on brain and behavior.

• Pharmacology, kinetics and dynamics

Primary effect

An effect desired for the purpose under discussion.

• Primary and secondary effects

Secondary effect

An additional, unintended effect, not necessarily a negative one.

• Primary and secondary effects

Biopsychosocial perspective

An explanation that considers biological, psychological, and social influences together.

• Biopsychosocial context and differences

Individual differences

Variation between people that can matter for their responses and experiences.

• Biopsychosocial context and differences

Causal inference

Reasoning about what produces an outcome; an intervention’s effect does not by itself identify every cause of the original condition.

• History and reasoning about drug effects

Central nervous system

Brain and spinal cord.

• CNS/PNS and brain regions

Peripheral nervous system

Neural connections outside the brain and spinal cord serving the rest of the body.

• CNS/PNS and brain regions

Ventral tegmental area

A midbrain region emphasized in the course’s dopamine pathway material.

• CNS/PNS and brain regions

Substantia nigra

A midbrain region connected to the striatum in the course’s movement pathway.

• CNS/PNS and brain regions

Nucleus accumbens

A forebrain region connected with VTA in the course’s reward-related pathway.

• CNS/PNS and brain regions

Dendrite

A neuronal process shown receiving signals in the introductory neuron model.

• Neuron organization and relational terminology

Axon

A neuronal process that carries signals toward terminal outputs in the introductory model.

• Neuron organization and relational terminology

Presynaptic

On the sending side of the particular synapse being discussed.

• Neuron organization and relational terminology

Postsynaptic

On the receiving side of the particular synapse being discussed.

• Neuron organization and relational terminology

Synaptic vesicle

A membrane-bound sac that stores transmitter within a neuron.

• Neuron organization and relational terminology

Action potential

A threshold-triggered, all-or-none electrical event that propagates along an axon in the course model.

• Action potentials

Depolarization

A change toward a less negative membrane potential in the illustrated action-potential cycle.

• Action potentials

Refractory period

The recovery interval associated with the action-potential cycle.

• Action potentials

Ligand

A molecule that binds to a receptor.

• Synaptic release

Vesicle fusion

Joining of vesicle membrane with terminal membrane during the modeled release process.

• Synaptic release

Reuptake

Transport of released material back into a cell; vesicular loading is a separate step.

• Signal termination

Vesicular transporter

A transporter that moves material across a vesicle membrane into the vesicle in the loading model.

• Signal termination

Diffusion

Passive dispersal that can carry transmitter away from the synaptic space.

• Signal termination

Synaptic plasticity

Changes in synaptic connections, including the formation and elimination emphasized by the course.

• Plasticity versus neurogenesis

Neurogenesis

The production of new neurons.

• Plasticity versus neurogenesis

Synaptic pruning

Elimination of some synaptic connections during remodeling.

• Plasticity versus neurogenesis

Glia

Non-neuronal cells introduced through support, myelin, and transmitter-handling roles.

• Glia

Myelin

An insulating covering around some axons that supports faster impulse transmission.

• Glia

Autoreceptor

A receptor for the transmitter released by the neuron on which it is located.

• Receptor classification

Heteroreceptor

A receptor for a transmitter different from the transmitter released by its host neuron.

• Receptor classification

Extrasynaptic

Located outside the synaptic contact region.

• Receptor classification

Ionotropic receptor

A receptor containing the ion channel controlled by ligand binding.

• Receptor signaling mechanisms

Receptor subunit

A protein component that assembles with others into a receptor.

• Receptor signaling mechanisms

G protein-coupled receptor

A receptor that signals through a coupled G protein.

• Receptor signaling mechanisms

Second messenger

An intracellular signaling molecule produced downstream of receptor activation in the described pathway.

• Receptor signaling mechanisms

cAMP

Cyclic adenosine monophosphate, the deck’s example of a second messenger.

• Receptor signaling mechanisms

Trk receptors

The receptor kinase family that the course includes as metabotropic without G-protein coupling.

• Receptor classification

BDNF

Brain-derived neurotrophic factor, linked to TrkB in the course.

• Receptor classification

Neurotrophin

A signaling molecule introduced through support of neuronal survival and growth.

• Receptor classification

Acetylcholine

ACh, the transmitter formed from acetyl coenzyme A and choline in the course example.

• Precursors and acetylcholine

Acetylcholinesterase

AChE, the enzyme that breaks down acetylcholine in the illustrated cleft.

• Precursors and acetylcholine

Precursor

A starting material used to synthesize another molecule.

• Precursors and acetylcholine

Choline

A precursor recycled into the terminal after acetylcholine breakdown.

• Precursors and acetylcholine

Nicotinic receptor

An ionotropic acetylcholine receptor class.

• Receptor classification

Muscarinic receptor

A metabotropic, G protein-coupled acetylcholine receptor class.

• Receptor classification

Monoamines

The transmitter grouping taught here through dopamine, norepinephrine, and serotonin.

• Monoamine transport

Catecholamines

The family including dopamine, norepinephrine, and epinephrine in the course.

• Monoamine transport

Tyrosine

The precursor starting the catecholamine synthesis sequence discussed in the deck.

• Monoamine transport

L-DOPA

DOPA, the intermediate following tyrosine in the course’s catecholamine sequence.

• Monoamine transport

Monoamine oxidase

MAO, an enzyme emphasized for monoamine metabolism.

• Monoamine transport
• Monoamine oxidase

Dopamine

DA, a catecholamine discussed across multiple pathways and functions.

• Dopamine families and pathways

DAT

Dopamine transporter, the course’s canonical dopamine membrane-uptake association.

• Dopamine families and pathways
• DAT

COMT

Catechol-O-methyltransferase, an enzyme discussed in catecholamine metabolism.

• Dopamine families and pathways
• COMT

D1 receptor family

The dopamine receptor family containing D1 and D5 in the deck.

• Dopamine families and pathways
• D1 receptor family

D2 receptor family

The dopamine receptor family containing D2, D3, and D4 in the deck.

• Dopamine families and pathways
• D2 receptor family

Mesolimbic pathway

The course’s VTA-to-nucleus-accumbens reward-related dopamine pathway.

• Dopamine families and pathways
• Mesolimbic pathway

Mesocortical pathway

The dopamine pathway discussed through cortical attention and working memory.

• Dopamine families and pathways
• Mesocortical pathway

Nigrostriatal pathway

The substantia-nigra-to-striatum dopamine pathway discussed through movement.

• Dopamine families and pathways
• Nigrostriatal pathway

Norepinephrine

NE, the catecholamine discussed through adrenergic receptors and central/peripheral signaling.

• Norepinephrine and adrenergic receptors

NET

Norepinephrine transporter, the course’s canonical NE membrane-uptake association.

• Norepinephrine and adrenergic receptors

Adrenergic receptors

The alpha and beta receptor families discussed for norepinephrine and epinephrine.

• Norepinephrine and adrenergic receptors

Locus coeruleus

The brainstem region emphasized in the deck’s central norepinephrine pathways.

• Norepinephrine and adrenergic receptors

Serotonin

5-hydroxytryptamine, abbreviated 5-HT.

• Serotonin and receptor exceptions

SERT

Serotonin transporter, the course’s canonical 5-HT membrane-uptake association.

• Serotonin and receptor exceptions

5-HT3 receptor

The ionotropic exception among the serotonin receptor families discussed in the course.

• Serotonin and receptor exceptions

Glutamate

The major excitatory amino-acid transmitter in the course’s introductory framing.

• Glutamate/NMDA and GABA comparisons

GABA

Gamma-aminobutyric acid, the major inhibitory transmitter in the introductory course framing.

• Glutamate/NMDA and GABA comparisons

NMDA receptor

An ionotropic glutamate receptor whose supplied activation model also requires relief of magnesium block and a co-agonist.

• Glutamate/NMDA and GABA comparisons

GABA-A receptor

The ionotropic GABA receptor class discussed in the deck.

• Glutamate/NMDA and GABA comparisons

GABA-B receptor

The metabotropic GABA receptor class discussed in the deck.

• Glutamate/NMDA and GABA comparisons

EAAT

Excitatory amino acid transporter, named in the glutamate uptake material.

• Glutamate/NMDA and GABA comparisons

GAT

GABA transporter, named in the GABA uptake material.

• Glutamate/NMDA and GABA comparisons

Histamine

A messenger introduced through H1 receptor discussion in this course.

• Histamine, peptides and other messengers

Opioid peptides

Peptide messengers including the deck’s endorphin and enkephalin examples.

• Histamine, peptides and other messengers

Hormone

A signal discussed through glandular release and wider circulation beyond a synapse.

• Histamine, peptides and other messengers

Endocannabinoids

Endogenous messengers introduced through regulation of other transmitter release.

• Histamine, peptides and other messengers

Adenosine

A messenger connected to energy metabolism and sleep/wakefulness in the deck.

• Histamine, peptides and other messengers

ADME

Absorption, distribution, metabolism and excretion: four processes used to organize drug handling.

• Pharmacokinetics and ADME

Systemic bioavailability

The fraction of an administered dose that reaches systemic circulation unchanged.

• Absorption and bioavailability

Enteral route

An administration route involving the gastrointestinal tract, including oral and rectal delivery in this course.

• Oral and rectal administration

Sublingual

Delivery under the tongue for absorption through oral mucosa.

• Inhaled and mucosal routes

Buccal

Delivery at the inner cheek or gum for absorption through oral mucosa.

• Inhaled and mucosal routes

Depot formulation

A formulation that serves as a reservoir from which drug is released over time.

• Skin delivery and injection routes

Transdermal

Delivery across skin into systemic circulation.

• Skin delivery and injection routes

Distribution

Movement of drug between blood and body tissues.

• Distribution, membranes and protein binding

Plasma protein binding

Reversible association of a drug with proteins in plasma, distinguishing bound from unbound drug.

• Distribution, membranes and protein binding

Blood-brain barrier

A selective interface regulating movement between blood and brain tissue.

• Blood-brain and placental barriers

Placental transfer

Movement of substances across the placental interface between maternal and fetal compartments.

• Blood-brain and placental barriers

Excretion

Removal of drug or metabolites from the body.

• Excretion and the kidney-liver connection

Renal reabsorption

Movement of material from renal tubular fluid back toward the circulation.

• Excretion and the kidney-liver connection

Active metabolite

A product of metabolism that retains or produces pharmacological activity.

• Enzymes and phases of metabolism

Conjugation

A metabolic reaction that attaches another chemical group to a compound.

• Enzymes and phases of metabolism

Cytochrome P450 (CYP)

An enzyme family important in the metabolism of many drugs.

• Enzymes and phases of metabolism

Enzyme induction

An increase in relevant enzyme expression or activity.

• Enzyme induction, inhibition and variation

Enzyme inhibition

A reduction in an enzyme's activity.

• Enzyme induction, inhibition and variation

Prodrug

A compound administered so that metabolic conversion produces an active drug.

• Prodrugs and first-pass metabolism

First-pass metabolism

Metabolism before a dose reaches systemic circulation, often involving the gut wall and liver.

• Prodrugs and first-pass metabolism

Half-life

The time required for a concentration to fall by half in the specified kinetic phase.

• Half-life and redistribution

Redistribution

Movement of drug between tissue compartments after its initial distribution.

• Half-life and redistribution

Steady state

A stable repeating exposure pattern in which average drug input and elimination balance.

• Therapeutic window, steady state and washout

Washout

The decline in drug exposure after input stops; active metabolites may have different time courses.

• Therapeutic window, steady state and washout

Tolerance

A reduced response to the same dose with repeated exposure.

• Tolerance, dependence and discontinuation

Physical dependence

Adaptation to continued drug exposure that can produce withdrawal when exposure decreases or stops.

• Tolerance, dependence and discontinuation

Affinity

A ligand’s tendency to bind a target under specified conditions; binding does not by itself establish activation.

• Receptor signaling mechanisms

Potency

The dose or concentration needed to produce a specified effect in a defined system.

• 3.2 · Read dose-response curves and compare agonists

Efficacy

Capacity to produce a functional response; maximal response must be compared within a specified system.

• 3.2 · Read dose-response curves and compare agonists

Partial agonist

A ligand producing a lower maximal response than a reference full agonist in the same system; not necessarily less potent.

• 3.2 · Read dose-response curves and compare agonists

Reversible competitive antagonist

A ligand that reversibly competes with an agonist at a binding site; the simple equilibrium model predicts a rightward agonist curve shift with the maximum preserved.

• 3.2 · Read dose-response curves and compare agonists

Therapeutic index

A ratio between specified population toxicity or lethality and effectiveness endpoints, such as TD50/ED50 or LD50/ED50; not an individual safe-dose guarantee.

• 3.4 · Therapeutic index, interactions and placebo reasoning

Quantal ED50

Dose at which 50% of a studied population meets a specified effect endpoint; distinct from half of a graded maximum.

• 3.4 · Therapeutic index, interactions and placebo reasoning

Polypharmacy

Use of multiple medications; the term alone does not establish whether a combination is appropriate or how it interacts.

• 3.4 · Therapeutic index, interactions and placebo reasoning

Nocebo effect

An adverse response associated with negative expectations or treatment context.

• 3.4 · Therapeutic index, interactions and placebo reasoning

Receptor downregulation

A reduction in receptor availability during adaptation; distinguish receptor number from other changes in signaling sensitivity.

• 3.3 · Acute effects, adaptation and tolerance

Addiction

A pattern of compulsive or poorly controlled use despite harm; physical dependence alone does not establish it.

• 4.1 · Addiction, dependence and biopsychosocial context

Comorbidity

Conditions occurring together; co-occurrence alone does not establish a direction of causation.

• 4.1 · Addiction, dependence and biopsychosocial context

Reinforcement

A consequence that increases the likelihood of a behavior; it can add an outcome or remove an aversive condition.

• 4.2 · Reward circuits, reinforcement and adaptation

Extinction

Reduced responding when a previously reinforcing contingency is no longer present; not necessarily permanent erasure of learning.

• 4.3 · Cues, stress, glutamate and model limitations

Reinstatement

Return of a previously extinguished response under conditions such as a cue, stressor or drug exposure in the described experiment.

• 4.3 · Cues, stress, glutamate and model limitations