If there’s any possibility that a brain may be right for us, I usually say yes. The brains we seek are rare and precious, and we don’t get nearly enough.
Once we have settled on potential candidates, our technicians contact each one’s next of kin to make a wrenching request: Would you consider donating your loved one’s brain to medical research?
It seems a simple question. Yet a few hours earlier, these people were alive. Now they are forever lost, and we are asking parents or spouses or children to see through their own shock and grief to give us the most personal part of their loved ones, the part that made up the very essence of who they were. Not surprisingly, perhaps, only about a third of them agree to donate the brains we seek.
When a brain arrives at our bank, we label it with a number in order to protect confidentiality. Then our job begins in earnest. We can now cut this specimen open and study its inner workings in an attempt to better understand mental illness.
It is among these brains—sliced up and frozen in a slurry of hope and optimism that they will one day reveal their secrets—that I do my work.
Brains are a bloody business. I’ve worked with them for over thirty years, starting with rat brains, each of which is the size of a walnut, smooth, and relatively simple. They have none of the intricate folds and crevices—called gyri and sulci—of the human brain.
By contrast, the human brain is large, elaborate, and far more complex. It is a feat of evolutionary engineering. All of its folds, all of those gyri and sulci, ridges and crevices, help to squeeze more storage and function into the relatively small space of the human skull. Consciousness is one of the many products of this marvelously complicated piece of tissue. Unfortunately, mental illness—an affliction of consciousness—is a product as well.
In our quest to understand what’s wrong in the brains of people with mental illness, we have to dig deep into the brain’s tissues, cells, and molecules. Novel techniques make this a little easier every year. To try to unlock the secrets of schizophrenia, for instance, I examine thin slices of brain stained with radioactive or fluorescent dyes and evaluate the cells’ various molecules, proteins, and types of RNA and DNA. To read their genetic code, I analyze the brain cells’ minute molecular composition with modern sequencing machines.
As a neuroscientist and molecular biologist, I’m an expert on the brain. But I’m not a clinical doctor. Before I became head of the brain bank, I’d never worked with intact human bodies or even identifiable body parts. I did my work in quiet laboratories far from morgues and hospitals, and by the time the brains got to me, they didn’t look like brains at all. They were pulverized bits of frozen tissue that looked like specks of pinkish flour suspended in liquid in little test tubes, or they were thin slices of tissue preserved in foul-smelling chemicals. They could have been almost anything or come from almost any organism.
It never bothered me to be both intimate with and distant from the subjects of my studies. After all, that is the nature of scientific research. Each scientist works on her own small, discrete piece of an overwhelming puzzle that she hopes will someday be solved by researchers’ collective efforts and to which her narrow contribution will have been some significant part.
Before I took this job, I’d never even touched a whole human brain. I’d been to a morgue several times, seen bodies splayed open with their organs removed. But I’d never seen a brain lifted out of a skull. I’d never held a whole brain in my hands, much less cut one apart.
“You have to do it yourself,” my predecessor at the brain bank, Dr. Mary Herman Rubinstein (known as Dr. Herman), urged me in 2013 as she trained me. “When we get the next brain, we’ll slice it up and freeze it together.”
So we do. On a sunny day in September of that year, with the leaves just beginning to turn yellow and red but the air still warm and comforting, we stand in the lab awaiting the arrival of my first brain. We are armored in protective gear—surgical masks strung from ear to ear, plastic shields over our faces, hair caps secured tightly around our foreheads, several layers of latex gloves that cover our arms up to our elbows, white lab coats overlaid with plastic aprons to protect us from splashing blood, and plastic booties covering our shoes.
A technician carries in a large white cooler, the kind that holds beer and steaks for a football tailgate party. This cooler, I know, contains a human brain packed in lots and lots of ice.
It is critical that the brain stays cold, because this helps slow the process by which tissues break down. For our experiments, the brain cells’ RNA—key to how genes are expressed—must be intact. Putting a brain on ice immediately after it’s removed from the body is the first step in preserving the RNA, but for long-term storage, we must quickly deep-freeze the tissue. Keeping the brain at very low temperatures can halt RNA decomposition for decades.
Dr. Herman opens the lid of the cooler and carefully lifts out a clear plastic bag frosted with ice. She slowly takes out the brain and places it in my outstretched palms. It fits comfortably in my hands. Heavy, cold, and wet, it drips with blood just like any other piece of meat. The average brain weighs 1,300 grams, or about three pounds; in time, I will see some that are as large as 1,800 grams, about four pounds. It feels like firm Jell-O, but in fact it’s quite fragile; if I’m not careful, parts might snap off.
Given that the human brain is the most complex structure in our universe, you’d expect it to look more . . . well, complicated. But it just doesn’t appear all that extraordinary. The
