Researchers at Chicago’s Northwestern Medicine announced a breakthrough this month in confronting Alzheimer’s Disease.

Like many scientific advances, it took years of grinding work.

But the young man behind this discovery had some deeply personal reasons to keep going in the face of long hours, long odds and even broken bones.

Chris Bissonette was just a kid when his grandfather succumbed to Alzheimer’s.

All he really understood was that his grandfather was losing memories, and then he moved into the hospital.

The picture got clearer years later, when Bissonette was working a summer job at a lab.

BISSONNETTE: And the lab housed the British Columbia brain bank, with hundreds of brains of people with Alzheimer’s Disease.

Bissonnette would see their medical records.

And he came to learn the disease is even more grisly than he’d thought.

BISSONNETTE: Descriptions by doctors of someone screamed all night because they couldn’t sleep and they didn’t know what was happening and they no longer had a personality. There is a horrible end to people with Alzheimer’s Disease that most people don’t really know about. I wanted to make it so that these people had some hope.

So he threw himself into brain science.

He learned the culprit in early Alzheimer’s seems to be one particular kind of brain cell crucial for accessing memories.

BISSONNETTE: They’re kind of like librarians in a library, and now suddenly with them all dead, people don’t really know where everything’s stored. It’s not that the memories in peoples brains are being destroyed, it’s just that the brains are unable to retrieve them.

Save or replace those cells, and maybe you could outsmart the disease.

As a grad student he joined the lab of Dr. John Kessler at Northwestern.

Bissonnette wanted to use human embryonic stem cells to figure out how to grow the affected brain cells from scratch.

Kessler says he tried to talk him out of it.

KESSLER: To be perfectly honest, I said you know, Chris, this may be too tough a project for you to be doing as a student. Perhaps we should do this with mouse cells. Chris’s response to me was, no …

BISSONNETTE: I don’t really care if mice have Alzheimer’s, and I don’t care if mice are able to remember stuff. So I want to be able to have an impact in the actual human disease.

And so he began what would become a six-year project in a windowless lab.

BISSONNETTE: So this is the stem cell lab here. And so, all of the air inside this room has been filtered twice.

SPITZER: How much time would you say you’ve spent in this room?

BISSONNETTE: Thousands of hours.

The narrow, yellowish room is lined with fridges, incubators, a canister of liquid nitrogen.

Stem cells can develop into any type of cell in the body.

Bissonnette painstakingly manipulated them with different solutions.

Getting the right formula took many educated guesses, and lots of wrong turns.

BISSONNETTE: You’d think you were on the road to getting the right kind of cells, and then at the end you’d check to see what you’ve made, and they’re entirely wrong. So you know that a month of your work was completely wasted, and for the next month you’re not going to get anything better.

The cells need constant attention – missing work was not an option.

Twice, Bissonette broke bones in bike accidents and was right back in the lab – once even before the bones were set.

Again, his mentor John Kessler pleaded with him to take it easy.

KESSLER: He came in, he was obviously in a lot of pain, his arm was in a sling, it just didn’t stop him.

Eventually Bissonnette cracked the code.

The lab can now grow virtually unlimited numbers of the brain cells.

That means scientists will be able to test thousands of drugs and maybe, someday, even transplant the cells into a sick person’s brain.

Kessler attributes the breakthrough to Bissonette’s determination.

KESSLER: Chris is as good as any student I’ve had in my laboratory in 30 years. He is really that good, and that smart. You know I sometimes feel that if I had a half a dozen people like Chris, there’s no disease we couldn’t deal with.

So what do you do when you pulled off a scientific coup at age 29?

If you’re Chris Bissonette, you apply to business school.

BISSONNETTE: I don’t have the energy to work 18 hours a day, 7 days a week any more. I’m never going to find another discovery that’s going to be as large as the first stem cell therapy for Alzheimer’s Disease. So I think I could have a much bigger impact in science by leaving academic science.

Bissonette wants to help biotechnology firms bring discoveries to market.

After all, the real breakthrough will come when the advances he’s made move beyond that windowless lab, and to a patient’s bedside.

(Hear an extended interview with Bissonnette here)