Follow an electrical signal into a chemical message, then trace its clearance and recycling.
Sources and model limits
Original schematic. Positions show relationships; structures and concentrations are not to scale.
Julien's Primer of Drug Action · 15 · 2 · Inside a working synapse · PDF 26, 27, 30, 31 · 2.11, 2.17, 2.18
Course notes and existing practice
Learning objective
Connect electrical arrival, calcium entry, vesicle fusion, and receptor binding without confusing transmitter with ions.
From arrival to release
In the core model, an arriving action potential opens voltage-gated calcium channels at the terminal. Calcium entry supports vesicle fusion with the presynaptic membrane, releasing transmitter into the cleft. The vesicle membrane and the released molecules are different modeled objects.
Binding is not passage through a pore
Released transmitter can bind and unbind at compatible receptors. The modeled receptor response changes ion-channel activity and therefore ion movement. Transmitter is the ligand; it does not become an ion or travel through the postsynaptic channel pore. The deck’s key-and-lock analogy illustrates compatibility, but does not replace the physical mechanism.
Ligand
A molecule that binds to a receptor.
Vesicle fusion
Joining of vesicle membrane with terminal membrane during the modeled release process.
Calcium supports release; transmitter binds outside an ion pore. Membrane uptake and vesicular loading are separate. Boxes group related structures; positions are illustrative, not anatomical scale. Read the accompanying lesson for causal and alternative routes.
Professor deck 2, PDF pages 19, 20, 21. Explanation and terminology are paraphrased course material. Examples and study prompts are original, unscored teaching aids. Source conformance is separate from scientific or clinical review.
Worked examples are original instructional illustrations; they are not professor quotations or exam requirements.
Sección: MASTER_SPEC section 3; prof-02 pp.19–21; transcript-a approximately pp.13–16
Release, receptor binding, termination and transporter correction
Paráfrasis
Revisado
Página 20
Synaptic release and receptor interaction: source-conformance review
Paráfrasis
Revisado
Página 19
Sección: PDF pages 19, 20, 21; paraphrased from embedded text and reviewed diagram labels. Review means source conformance, not independent clinical validation.
PolyDiscipline original study examples
Explicación original
Revisado
Sección: Phase 5 teaching illustrations and unscored reflection prompts; not professor quotations or assessment items.