The chemistry
that rides the membrane.
Neurotransmitters get the headlines, but they only mean something because a membrane is there to receive them. Chemistry is the message; the membrane is the medium.
Brain chemistry is often taught as a cast of molecules — dopamine, serotonin, glutamate, GABA. But a neurotransmitter floating in a dish does nothing. It becomes a signal only when it meets a receptor embedded in a membrane, which opens a channel and changes the voltage across the boundary. SMX puts the membrane back at the centre of the story.
One handoff, four membrane events.
Every chemical signal in the brain runs the same four-beat loop across the synapse. Each beat happens at, or through, a membrane.
Release
An electrical spike reaches the terminal. Vesicles fuse with the presynaptic membrane and spill neurotransmitter into the gap.
Binding
Transmitter drifts across and locks onto receptors studding the postsynaptic membrane — a key finding its lock.
Response
Bound receptors open ion channels. Charge floods in or out, nudging the neuron toward firing — or away from it.
Reset
Transmitter is cleared, pumps restore the voltage, and the membrane is primed for the next message — milliseconds later.
A small cast with enormous range.
The same handful of transmitters, in different circuits, produce focus, calm, motivation, and memory. Their effect always depends on which receptors the receiving membrane presents.
Glutamate
The brain's main "go" signal and the workhorse of learning. Central to how synapses strengthen when you form a memory.
GABA
The main "stop" signal. It quiets over-excited circuits and keeps the whole network from tipping into noise.
Dopamine
Tunes motivation, reward, and movement. It doesn't shout "fire" — it changes how loudly everything else is heard.
Serotonin
Shapes mood, sleep, and appetite by adjusting the tone of vast stretches of cortex at once.
Acetylcholine
Sharpens attention and encoding. Its membrane receptors are among the first casualties in cognitive decline.
Phospholipids
Not transmitters, but the substrate. The membrane's own lipids set how readily every receptor above can do its job.
The membrane is a chemical, too.
Here's what SMX insists on: the lipids that build the membrane are active players in brain chemistry, not inert scaffolding. Phosphatidylserine concentrates at synapses and supports receptor function. DHA, an omega-3, keeps the membrane fluid enough for receptors to move and cluster. Change the fats, and you change the chemistry.
This is why diet reaches the brain at all: you are, in a real sense, building tomorrow's synapses from today's meals.
- DHAOmega-3 tail → membrane fluidity → mobile receptors
- PSPhosphatidylserine → synaptic density & signalling
- PCPhosphatidylcholine → precursor to acetylcholine
- CHOLCholesterol → tunes stiffness of the bilayer
Chemistry needs a membrane that holds.
All of this signalling assumes an intact boundary. Next: what damages membranes, and how the brain defends the surface it depends on.
Pillar 03 · Membrane Integrity →