You probably never imagined the inner ear of a developing zebrafish could hold so much drama.

There’s the immune cell trying to establish a relationship with sugar particles. Elsewhere, a cancer cell is trying to hook up with the wall of a blood vessel.

There is, in fact, so much drama — cells swishing and swirling around — you might wonder how that zebrafish’s ear gets any work done at all.

Or you might just wonder how we could ever be witnesses to the comings and goings of such tiny cells inside a living animal.

Well, that would be thanks to pioneering efforts of researchers at the Howard Hughes Medical Institute in Maryland, who, for the first time ever, have managed to record high-definition video of cells moving inside a live animal.

Their findings, published in the journal Science this month, offer an unprecedented glimpse into the bustling universe that exists within us all.

Until now, scientists have struggled to observe the stars that animate our bodies — the working cells — without changing their natural ecosystem.

Cells are typically extracted and studied on glass slides or blasted with light so powerful it may disrupt their natural workings.

"This raises the nagging doubt that we are not seeing cells in their native state, happily ensconced in the organism in which they evolved,” says lead author Eric Betzig, a Nobel Prize-winning physicist at the Howard Hughes Medical Institute, in a statement. "It's often said that seeing is believing, but when it comes to cell biology, I think the more appropriate question is, 'When can we believe what we see?'"

Instead of the traditional approach, the research team developed a new technique to peer gently behind the curtains on the theater of life. This let them watch the bustle of cell biology within a living animal — and record it in 3-D.

To do this, the researchers took a technical cue from astronomy. They used ultra-thin wafers of light to capture two-dimensional snapshots, then matched those images with adaptive optics — a technique astronomers use to peer deeply into the cosmos.

The result? A fascinating and vivid glimpse into what scientists call a “bustling metropolis in action at the subcellular level.”

And it is indeed bustling. In a series of recordings, cells are seen going about very specific missions like a teeming ant colony. One movie shows a very orange immune cell shimmying along the zebrafish’s ear, gathering up sugar particles. A cancer cell debuts in another video, rumbling along a blood vessel and trying to find a place along its wall to get some traction.

The microverse is a strange, sometimes scary place in high-definition 3-D.

For the research team, the next step will be to downsize the microscope. The model they built for the job is heavy and bulky, sprawling across a 10-foot table. But once streamlined, it could be used to capture cellular cinema in labs around the world.

And life, as we never knew it before, will be ready for its close-up.

Scientists can see cells moving inside live animals for the first time
Stunning 3-D videos capture the drama of life on a subcellular level.