You can try the first discovery and the 3D controls now. Stella unlocks every stage.
Synapse: Where Memory Forms
Follow one signal as it enters a neuron, becomes a spike, crosses a synapse, and strengthens a pathway into memory.
From the dendrites to the synapse, see it as a journey of the signal
A neuron has branches that receive input, a soma that decides, an axon that sends far, and a synapse that passes to the next. First read it as the route the signal travels, not as part names.
Basics: OpenStax Biology 2e: How Neurons .
In the "See the shape" stage, without adding controls, confirm the order of the soma, axon, terminal, and synapse.
Where it is moving now: Input → stopped at the soma / Stopped at the soma
Center the soma and axon hillock that receive input and head toward firing.
You can try the first discovery and the 3D controls now. Stella unlocks every stage.