Synapse & Neurotransmitters

Synapse & Neurotransmitters 3D brings chemical neurotransmission to life at the molecular scale. Students view the presynaptic axon terminal bulb with voltage-gated calcium channels, glowing neurotransmitter vesicles, and a reuptake transporter pump positioned above the synaptic cleft and postsynaptic dendrite receptors. Dragging a vesicle to the presynaptic membrane or clicking any structure triggers exocytosis, releasing neurotransmitter molecules that bind ligand-gated ion channels below. Controls for action potential rate, calcium influx, and pharmacology let students compare normal signalling with SSRI reuptake inhibition, competitive receptor blockade, and enzyme inhibition.

• Drag the glowing green synaptic vesicle down to the presynaptic membrane to trigger exocytosis and flood the cleft with neurotransmitter molecules.
• Increase Action potential rate and Calcium influx until the Postsynaptic potential readout crosses the -55 mV threshold to fire an action potential.
• Select Reuptake Inhibitor (SSRI) in the Pharmacology menu to block the pink reuptake pump and see neurotransmitter concentration stay elevated in the cleft.
• Select Receptor Blocker to occupy the postsynaptic ion channels and observe why high neurotransmitter levels fail to depolarise the dendrite.

1. 1Describe the sequence of events at a chemical synapse from presynaptic depolarization and Ca2+ influx to vesicle exocytosis.
2. 2Explain how neurotransmitter binding opens ligand-gated ion channels to generate an excitatory postsynaptic potential (EPSP).
3. 3State the role of threshold potential (-55 mV) in triggering a new postsynaptic action potential.
4. 4Predict how reuptake inhibitors, enzyme inhibitors, and receptor antagonists alter synaptic transmission.

Questions teachers ask