Cross-Bridges Over Troubled Water

This parody (written by Greg Crowther) is sung to the tune of "Bridge Over Troubled Water" (written by Paul Simon and performed by Simon and Garfunkel).

In the context of muscle physiology, "bridges" are the cross-bridges that myosin heads form when they bind to actin, the molecular mechanism for force generation.

When you're weary --
Low on ATP --
Your frontal lobe moves you...
Electrically!
And your brainstem, too...

Oh, when neurons fire,
And acetylcholine’s all around,
You’ll find bridges through the muscle fibers,
Where the actin’s bound!
You’ll find bridges through the muscle fibers,
Where the actin’s bound!

Slide on, filaments;
Slide on by!
Your time has come to bind!
Excitation’s underway;
Membrane voltage climbs...

Oh, if SR channels open,
And calcium is all around,
You’ll find bridges through the muscle fibers,
Where the actin’s bound!
You’ll find bridges in the muscle fibers,
Where the actin’s bound!