How sleep deep cleans your brain

Jeffrey Iliff at TEDMED 2014. Photo: TEDMED/Sandy Huffaker
Jeffrey Iliff at TEDMED 2014. Photo: TEDMED/Sandy Huffaker


In his TEDMED 2014 talk, neuroscientist Jeffrey Iliff illuminated a newly discovered, critical function of the brain during sleep: a natural cleansing system that keeps toxic proteins at bay.  We spoke to him via email about his talk.

What motivated you to speak at TEDMED?

TEDMED offered the unique opportunity to tell the story of our research – not just its facts, but also its story. As a neuroscientist, I go to the lab every day expecting to see something new within the brain, its pieces, processes, and the systems that comprise it that no one has ever seen before. What we find within the brain – its simplicity, minimalism, functionality, and its beauty – are a continuous source of wonder to me. In the methods, results, and careful interpretation of our findings, this wonder can easily be distilled. When the outside world looks in at our work, they may only see cells, blood, water, and so many solutes; not the beauty I see through the eyepieces of a microscope. TEDMED gave me the chance to tell the story of our work as we experience it, as the story that it is.

Why does this talk matter now? What impact do you hope the talk will have?

First, I think that it is a subject to which every person can relate. Each of us who is in school, works long hours at a job, or has kids to keep them up when they’re sick, deals with the inescapable fact that sleep is necessary for our brains to work correctly. Learning that parts of the way our brains work can make intuitive sense is comforting, and makes our brains seem a little less like these strange alien machines that no one can really understand.

I think that the research itself is timely, as well. An increasing number of clinical studies have begun to link such seemingly disparate processes as sleep, neurodegenerative disease, cardiovascular disease, brain injury and others. The science that we describe, and that is the subject of my talk, is fundamental to the basic function of the brain and may help to explain many of these puzzling associations. My hope is that my TEDMED talk will spur people’s imaginations and encourage them to dive headfirst into these questions and, in doing so, drive the field forward far beyond these small contributions that we’ve made.

What kind of meaningful or surprising connections did you make at TEDMED?

During the conference, I was approached by several people who were attending TEDMED for their own professional reasons, but who had also dealt – either personally or within their immediate families – with conditions that are likely impacted by the biology that we are studying. For those of us who are scientists, but not physicians, it is incredibly easy to view our work academically, to equate progress with papers and grants, and to view treatments as ideas and hypotheses to be tested. To an extent, this is completely appropriate. But, I was reminded that, when I talk about “Alzheimer’s patients” in a scientific talk, those words stand for millions of mothers and fathers, grandfathers and grandmothers who live with this disease every day – each loved and missed as they slip slowly away. In the face of this reality, the thin replies of “We don’t know yet,” “Here’s what we think is happening,” or “Here’s something we’re testing in our mice” seem hollow and inadequate. It was a stark reminder to focus not only on what, but also whom we are trying to cure with all of this amazing science.