86 billion of these in your brain.
Each one a living wire.
Each one waiting for a signal
worth passing on.
Click any structure.
Everything has a reason
for looking exactly like it does.
RESTING · −70 mV
CONDUCTION: —
ALL-OR-NOTHING LAW
THE ACTION POTENTIAL
When input exceeds threshold, the membrane fires. Every time. Fully. The signal doesn't get stronger with more stimulus. It fires or it doesn't.
Na⁺ SODIUM
K⁺ POTASSIUM
Cl⁻ CHLORIDE
STIMULUS
STRENGTH
0
Threshold: 55 · Below threshold: no signal
CONDITIONS
MYELINATION
100%
TEMPERATURE
37°C
Na⁺ CHANNELS
100%
Normal conditions. Full myelination. Body temperature. All channels open.
VELOCITY
—
PEAK mV
—
DURATION
—
REFRACTORY
—
KEY PRINCIPLES
All-or-Nothing: Signal fires fully or not at all. Stronger stimulus does not mean stronger signal.
Saltatory Conduction: Myelinated axons jump signal node to node — up to 100x faster.
Refractory Period: Brief window after firing where the axon cannot re-fire. Signal travels one direction only.
THE SYNAPTIC CLEFT
20 nanometers wide.
Your entire emotional life happens in this gap.
NEUROTRANSMITTER
GLUTAMATE — Primary excitatory. Fires the next neuron. Learning and memory depend on it. Found at most synapses.
REUPTAKE
PUMP ACTIVITY
80%
Normal reuptake. Neurotransmitters cleared efficiently.
SSRI MECHANISM
Reduce reuptake to 0–20%. Serotonin lingers in the cleft. Signal strength and duration increase. This is the exact mechanism of every SSRI antidepressant ever made.
SIGNAL
RECEPTOR SENSITIVITY
100%
Normal sensitivity. Baseline receptor response.
CLEFT WIDTH
20 nm
NT IN CLEFT
0
POST POTENTIAL
−70 mV
SIGNAL TYPE
—
SIGNAL COHERENCE —
CLICK NEURON TO STIMULATE · DRAG TO PAN
NETWORK
NEURON COUNT
35
CONNECTIVITY
3
INHIBITORY %
20%
ACTIONS
PLASTICITY
Hebbian Rule:
Neurons that fire together wire together. Strengthen a pathway by firing it repeatedly. Watch the connection thicken.
Use it or lose it:
Starve a pathway and it weakens. This is how memory fades and skills atrophy.