[Verse 1]
Picture a wire running bare down a hall,
Every drop of current leaking through the wall,
Signal getting tired, fading before it's done,
Unmyelinated axon, slow like molasses run,
Half a meter, maybe two, each second it will creep,
That's the pace the naked fiber's forced to keep.
[Chorus]
Myelin, myelin, wrapped up tight,
Fatty rings of insulating white,
Nodes of Ranvier, gaps between,
Sodium gateways, electric sheen,
Jump, jump, saltatory leap,
Node to node the impulse takes a leap,
Myelin, myelin, keep the current steady,
Signal's sprinting, axon's ready.
[Verse 2]
In the brain and cord, oligodendrocyte's the name,
One cell reaching out, dressing axons all the same,
Many arms, many fibers wrapped in its embrace,
Layer after layer, a lamellae lace—
Thin sheets of membrane coiled round and round,
That's the word for stacking sheets without a sound.
Out in the body, Schwann cell does the chore,
One cell, one segment, nothing less, nothing more,
Loyal little wrapper, devoted to its patch,
Every axon's journey has a Schwann cell match.
[Chorus]
Myelin, myelin, wrapped up tight,
Fatty rings of insulating white,
Nodes of Ranvier, gaps between,
Sodium gateways, electric sheen,
Jump, jump, saltatory leap,
Node to node the impulse takes a leap,
Myelin, myelin, keep the current steady,
Signal's sprinting, axon's ready.
[Verse 3]
Why the hurry, why the insulated coat?
Capacitance drops, that's the trick they tote,
Current can't seep out through the fatty sleeve,
So it builds up fast, no time to grieve,
From one bare node the charge will roar and fly,
Straight across the sheath, no stopping by,
Lands on the next gap, channels open wide,
Hundred twenty meters a second, in full stride.
[Bridge]
Compare the two: one-twenty versus one,
Myelinated sprinter's left the slowpoke outrun,
Lose the wrap, the signal starts to stall,
That's multiple sclerosis, scarring through it all,
White matter's color comes from fatty sheen,
Strip the myelin, the tissue's lost its gleam.
[Verse 4]
Development's a timeline, sheaths don't come at birth,
Infant axons bare and slow, still proving worth,
Myelination marches on through childhood's climb,
Reflexes sharpen, coordination keeps its time,
Growth spurts in the cortex, wrapping thick and fast,
Building highways for the signals built to last,
Even into twenties still the process churns,
Learning, practice, myelin adapts and learns.
[Chorus]
Myelin, myelin, wrapped up tight,
Fatty rings of insulating white,
Nodes of Ranvier, gaps between,
Sodium gateways, electric sheen,
Jump, jump, saltatory leap,
Node to node the impulse takes a leap,
Myelin, myelin, keep the current steady,
Signal's sprinting, axon's ready.
[Outro]
Node to sheath, and sheath to node,
Down the fatty-wrapped highway road,
Ranvier's gaps light up the chain,
Saltatory fire down the lane.