A neuron is not a wire. It is a switching station where electricity becomes chemistry, then becomes behavior.
This lab renders an anatomical neuron specimen, a synapse close-up, and a rotatable NIH-derived brain mesh in Three.js. It covers six major neurotransmitter systems, with short explanations tied to source-backed anatomy instead of medical folklore.
The transmitter notes, source table, and methodology below remain readable.
The synapse is the gap where the signal changes form. The molecule is not the meaning. Meaning comes from receptor, region, timing, and the circuit already in motion.
A good neuron chapter should connect structure, timing, chemistry, and circuit context. Use the specimen first, then the stepper, then the tables. By the end, the labels should feel like a mechanism rather than vocabulary.
Before memorizing molecules, learn the logic. Inputs are summed, voltage becomes chemistry, receptors define the local effect, and brain regions make sense only as circuits.
The specimen is simplified, but the roles are real: dendrites receive, the soma integrates, the axon carries the spike, terminals release chemicals, and receptors decide what the next cell does with the message.
The same event has two languages. Voltage carries the message inside the sending neuron. Molecules carry it across the gap. Receptors translate it again on the receiving side.
Most incoming synapses land on dendrites. A single input is usually not the whole decision. The soma integrates many excitatory and inhibitory nudges before the axon initial segment fires.
A transmitter is closer to a control signal than a mood label. Glutamate and GABA handle fast excitation and inhibition. Dopamine, serotonin, acetylcholine, and norepinephrine often modulate how strongly circuits respond.
Ionotropic receptors open a channel directly. AMPA receptors are the classic fast glutamate example in this lab.
Metabotropic receptors change cell state through signaling cascades. The effect can be slower and broader.
Transporters, enzymes, and diffusion end the message. The off-switch is part of the computation.
A transmitter is only half the story. The receptor determines whether the receiving cell changes voltage immediately, changes its internal chemistry, or clears the signal and resets.
| Process | Tempo | Mechanism | Example | Takeaway |
|---|
The table mirrors the interactive panel so the page stays useful even without WebGL.
| Transmitter | Class | Primary action | Representative regions | Synapse note |
|---|
The chapter is useful only if it prevents the usual bad shortcuts: one molecule per feeling, one brain point per behavior, and excitation as a moral category.
The neuron and synapse are browser-built Three.js geometry with organic membranes, tapered dendrites, myelin wraps, vesicles, receptors, and transmitter particles. The brain mode loads an optimized NIH 3D GLB mesh so the map is a rotatable object, not a flat image. No Meshy key is shipped to the browser. If a future GLB asset is generated, the API key belongs in MESHY_API_KEY and the final file should be committed under /assets/models/neurotransmitter-atlas/.
Generated imagery is not used as the brain object. The labels, region notes, transmitter explanations, and interaction logic stay browser-native and source-backed so the atlas can be inspected, tested, and corrected.