[Verse 1]
Deep behind your temple, curled up like a seahorse shape,
A tiny archive keeps your yesterday from getting lost in space.
Entorhinal cortex is the mailroom at the gate,
It fires down the perforant path, no pause, it will not wait.
[Chorus]
Entorhinal to Dentate, Dentate to CA3,
Mossy fibers carry secrets through the gray relay,
CA3 sends Schaffer collaterals to CA1's door,
Trisynaptic, three stops ticking, that's the hippocampus tour!
[Verse 2]
Dentate gyrus is the bouncer, keeping lookalikes apart,
Two blurry memories walk in — it splits them clean, a separate start.
But CA3 loops back on itself, a tangled web, recurrent and tight,
Give it one torn fragment of a cue, it rebuilds the whole scene overnight.
That's attractor memory pulling the full picture from the rim,
Pattern separate, pattern complete — a tag-team, never grim.
[Chorus]
Entorhinal to Dentate, Dentate to CA3,
Mossy fibers carry secrets through the gray relay,
CA3 sends Schaffer collaterals to CA1's door,
Trisynaptic, three stops ticking, that's the hippocampus tour!
[Verse 3]
Nineteen seventy-one, O'Keefe found a cell that only sparked
When a rat stood on one square — a living map, a spot it marked.
The Mosers found the grid cells, triangles tiled in the brain's own floor,
Two thousand five, a hexagon compass, nobody'd seen before.
Twenty-fourteen, Stockholm called, three names upon the prize,
Place and grid cells, partners mapping world behind your eyes.
[Verse 4]
Henry Molaison, called H.M., lost both his hippocampi in '53,
Could learn a task with steady hands yet never knew he'd practiced, see.
No new memories could dock and stay, the present slipping like the tide,
His loss taught us this seahorse shape is where our long-term facts reside.
And in these very circuits, Bliss and Lømo watched a synapse grow,
Long-term potentiation — fire together, strengthen, glow.
[Verse 5]
At night the theta rhythm hums, a slow and steady eight-cycle wave,
Sharp-wave ripples replay the day, compressing what the synapse gave.
The cortex listens, slowly learns what the hippocampus rushed to save,
A nightly transfer, memory's courier, from temporary to engrave.
Sleep isn't idle — it's the archivist, sorting what the day interred,
Turning fragile traces into something permanent, something stirred.
[Bridge]
Perforant, mossy, Schaffer — three bridges, one river wide,
Separate then complete the picture, memory's architect inside.
Without this looping seahorse, moments drown before they're kept,
With it, experience turns to knowledge while the body slept.
[Chorus]
Entorhinal to Dentate, Dentate to CA3,
Mossy fibers carry secrets through the gray relay,
CA3 sends Schaffer collaterals to CA1's door,
Trisynaptic, three stops ticking, that's the hippocampus tour!
[Outro]
Dentate splits, CA3 fills in, CA1 sends it home,
Three synapses, one small seahorse, carrying everything you've known.