Candace Pert, section chief of brain biochemistry at the National Institute of Mental Health, is sitting in a barber's chair, having makeup applied for an appearance on "The MacNeil-Lehrer NewsHour." In just minutes, she will provide counterpoint to the author of a new study -- published recently in the prestigious New England Journal of Medicine -- which concludes that emotions have no effect on the survival of cancer patients.

The study, and an accompanying editorial by New England Journal deputy editor Marcia Angell, provoked outrage among emotions researchers. Pert considers it ludricrous that serious scientists could even think of dismissing the notion of a mind-body link for health and disease.

Moreover, she claims she has the proof -- a pile of scientific papers now sitting in her lap -- to back up that position. But it's still a formidable task to boil down the importance of a major revolution in biochemical research to a few short sentences -- even for an outspoken, and often ardent, advocate like Pert.

To prepare for her national television debut, Pert wedged a half-mile swim into a busy afternoon schedule that also included a trip to one of her three children's summer programs. She exercised to boost her level of beta-endorphins -- the natural, opium-like substances produced by the body. The endorphins, in turn, reduce anxiety and generally make people feel good.

The swim worked. She now feels "mellow," she tells friend and colleague Michael Ruff, who is along for a last-minute briefing and general moral support.

Just before walking into the studio to go on the air with Jim Lehrer, Pert turns and says: "Healing thoughts is what it's about. I'm in a great position. I'm representing the truth, and it's important for people to know it."

But on the air, some of the technical information about emotions research has Lehrer stumped. "I don't understand a word you just said," he tells Pert after she's attempted to describe the complex relationship between what she says are the chemical molecules of emotion and what they might mean to health and disease.

"Okay, right," she says, and tries again. "The revolution," Pert tells Lehrer, "is that the brain and the immune system and the glands are now communicating with each other."

Pert goes on to describe how these different body parts use the same chemical messengers to carry on a two-way conversation -- a thought that would have been scientific heresy just a few years ago. What this means is that the stomach can talk to the brain and then the brain can send signals to the pancreas.

Pert is on a roll now. She even manages to get in a swipe at the New England Journal editorial, calling it "extremely dangerous and irresponsible" of the journal "to print an editorial that closed the door on this type of scientific inquiry.

"They actually stated that it is an old wives' tale that mental states can influence health -- here at a time when we are showing that the same mood chemicals are making your body cells grow," Pert says.

"What we're talking about is a scientific revolution where immunologists and neuroscientists are starting to believe that they have found the biochemical basis of emotion and how it affects your body's integrity."

It may take a while for the rest of the world to catch up with scientists like Candace Pert as they delve into the complicated world of emotions. The key question is what impact behavior and feelings have on health and disease.

This is the old mind-body debate updated for the 1980s. It's the question of whether feelings and behavior -- everything from suppressing anger to feeling depressed -- have any effect on health. Only this time, the ball seems to be in the court of the emotion researchers, because sophisticated laboratory techniques now allow scientists to do everything from mapping individual receptors in the brain to measuring how white blood cells move in response to such diverse substances as heroin and adrenalin.

But some of the most intriguing news may be this: Pert and others believe they can reduce emotions to a few chemicals called neuropeptides.

"This is 1985," she says. "We're materialists, right? We don't believe in God, right? We believe in chemistry. And we all have emotions, and what are they made of? Neuropeptides."

The word neuropeptides means a brain-produced protein. In the old days, it meant a handful of substances. Today, 40 or 50 neuropeptides have been identified -- including many familiar substances like insulin (once known as a hormone) and a few new ones, like Substance P, which seems to be associated with pain and inflammation and is found in arthritis patients.

"My fantasy -- it's not even at the level of a hypothesis yet -- is that I can imagine that each neuropeptide may represent a different emotion," Pert says.

"An emotional state," adds Joanna Hill, a colleague of Pert's, "could be modified by a whole array of neuropeptides."

Already, studies show that neuropeptides can have a big effect on behavior. Take, for instance, angiotensin, a neuropeptide related to water regulation and thirst in the body. "Inject angiotensin into a rat's brain, and even if he's been drinking water for hours before, within 10 seconds he'll start drinking again just like a little robot," Pert says. "Interestingly, angiotensin works on the kidney to conserve water. It's an example of a neuropeptide working in the brain and in an organ to get the same end state -- conserve water."

The surprise is not just that neuropeptides work on different parts of the body. The surprise is that these substances, which have such a profound effect on how we act, are produced outside the brain in white blood cells. These cells, the macrophages, are also attracted to the chemical scent of these substances. Give them a whiff and white blood cells will march across a test tube, pass through a piece of gauze or even move across the supposedly impenetrable blood-brain barrier.

Among the neuropeptides attractive to white blood cells are opiates, the pleasure-producing class of drugs that include heroin, morphine, beta-endorphins and Substance P.

Some of the most recent work, soon to be published in the journal Science, shows that there are receptors on white blood cells for benzodiazepines, the anti-anxiety drugs such as Librium and Valium.

The discovery of these receptors on white blood cells, plus the fact that immune cells can produce substances once thought to arise only from the brain, "suggests a psychosomatic pathway of communication," within the body, report Pert and coauthors Michael Ruff, Sharon Wahl, Larry Wahl and Steven Paul in the Science article.

Not surprisingly, research in emotions is exploding. This month's issue of the Journal of Immunology published its first 125-page special supplement on the many interconnections between the immune system and the brain. Other reports are appearing in journals such as Science and Nature.

Pert is one of the leaders in this field. Her recent work includes:

*A study to appear in Clinical Immunology and Immunopathology describing a possible way cancer spreads throughout the body. The four authors -- Ruff, Pert, Elliott Schiffmann and Victor Terranova -- found that neuropeptides attract human tumor cells and a type of white blood cell called a monocyte. The scent of these neuropeptides causes both cancer and white blood cells to move toward a concentration of these substances, a process called chemotaxis.

*A paper published last year in the Journal of Biological Psychiatry, in which Pert, Richard Weber and Lynn DeLisi reported that schizophrenic patients seem to have antibodies in their blood against brain cells. This is one indication that schizophrenia may be a reaction against the brain by the immune system, what scientists call an autoimmune response.

*In this month's Journal of Immunology, a report by Pert and Ruff showing that glial cells in the brain appear to originate from white blood cells produced initially in the bone marrow. The paper is just one in the journal supplement describing the numerous, and until recently unheralded, interconnections between nervous and immune systems -- the mind-body connection.

Other findings suggest that macrophages may actually be a kind of free-moving nerve cell capable of communicating with the nervous system, but classified as a white blood cell. Nerves in the body serve as stationary wiring for messages, kind of like a telephone line. They're fast but may not always get the message delivered to the right place. Macrophages can deliver a special message where there may not otherwise be wiring, similar to a hand-delivered message. "It's like a cellular pony express," explains Ruff. "It has maximum flexibility, but probably not maximum speed."

The appearance of such theories and studies in a major scientific journal is "unheard of," says Sharon Wahl, chief of the immunology section at the National Institute of Dental Research and a coauthor of the Science study. "It used to be that people laughed when you said that you were studying the relationship of mood and . . . immunity."

"But now this is legitimate," she says, pointing to the Journal of Immunology supplement. "This will open doors to a lot more kinds of studies."

And the potential significance is staggering. Asthma. Schizophrenia. Depression. Arthritis. "I would like to challenge someone to tell me one disease that is not psychosomatic," says Pert.

William James is considered the father of American psychology. In June, Candace Pert stood in James Hall at Harvard University and gave the keynote address at the inaugural meeting of the International Society for Research on Emotions. The conference marked the second international society to form within the year for the study mind-body connections. (Last fall, the First International Meeting on Neuroimmunodulation held its first meeting on the NIH campus in Bethesda.)

Projected behind Pert was a giant autoradiograph of a monkey's limbic system -- the portions of the brain that have been proven during surgery to be the seat of emotions. The colors border on the psychedelic. They represent where specific neuropeptides operate, in this case opiates, indicating that opiates are one of the chemical essences of emotion.

"Emotions," Pert tells the audience, "have a lot to do with survival. It's interesting to speculate that neuropeptides are synchronizing the organism. They're literally flowing and squirting out from one place to the other. I didn't mention that neuropeptides are not just found in the brain and that they're not just found in the gut. There are huge quantities in the ovaries and in the heart."

Pert ought to know. This 39-year-old scientist performed landmark work on opiate receptors. Educated at Bryn Mawr College in Pennsylvania, she married early, began a family, but still managed to keep studying. Post-doctoral work at Johns Hopkins with Solomon Snyder thrust her into the limelight when Snyder won a coveted Lasker Award, in 1979.

Pert moved to NIMH shortly afterwards with her psychologist husband. Both have been there ever since, although they divorced several years ago.

Today, Pert is a section chief, who this year earned tenure -- a situation that gives her the job security necessary to pursue this sometimes still controversial area. But despite the fact that research on emotions is expanding rapidly, Pert and her colleagues often wage battles not just against disease but also against the shrinking research dollar.

On a recent day, dressed in Army camouflage pants and a T-shirt, she lectured to a group of 15 or so psychiatric fellows on the rewards of collaborating in basic research.

"It's not outrageous to think that our mood states can alter where our white blood cells move," Pert told them.

"You could charge that it's only of academic interest to have a biochemical theory of emotions, but anyone interested in mental illness -- and presumably psychiatrists are interested in mental illness -- understands that these very sick people are obviously suffering the pathology of emotions."

"Finally," Pert said, "let me say a word about the mental diseases themselves. I think that it is highly likely that many of these diseases have an autoimmune basis. I think that within the next year or two we are going to see some incredible breakthroughs documenting schizophrenia as an autoimmune disease."

"Charles Darwin wrote a book about emotion a hundred years ago," Pert said. "On the last page, he wrote that one day we will unearth the physiological mechanisms of emotion. I think we've got it."