Friday, July 23, 2010

social pain

Acetaminophen (tylenol) reduces physical and social pain.

derek bowds

DeWall et al. show that an anti-pain medication that acts on the brain's pain pathways, reduces both physical and social pain:
Pain, whether caused by physical injury or social rejection, is an inevitable part of life. These two types of pain—physical and social—may rely on some of the same behavioral and neural mechanisms that register pain-related affect. To the extent that these pain processes overlap, acetaminophen, a physical pain suppressant that acts through central (rather than peripheral) neural mechanisms, may also reduce behavioral and neural responses to social rejection. In two experiments, participants took acetaminophen or placebo daily for 3 weeks. Doses of acetaminophen reduced reports of social pain on a daily basis. We used functional magnetic resonance imaging to measure participants’ brain activity, and found that acetaminophen reduced neural responses to social rejection in brain regions previously associated with distress caused by social pain and the affective component of physical pain (dorsal anterior cingulate cortex, anterior insula). Thus, acetaminophen reduces behavioral and neural responses associated with the pain of social rejection, demonstrating substantial overlap between social and physical pain.

Tuesday, July 20, 2010

sapolsky on stress

Posted on: July 19, 2010 11:49 AM, by Jonah Lehrer

I've got a new article in the latest Wired on the science of stress, as seen through the prism of Robert Sapolsky. The article isn't online yet (read it on the iPad!), but here are the opening paragraphs:

Baboons are nasty, brutish and short. They have a long muzzle and sharp fangs designed to inflict deadly injury. Their bodies are covered in thick, olive-colored fur, except on their buttocks, which are hairless. The species is defined by its social habits: The primates live in troops, or small groupings of several dozen individuals. These troops have a strict hierarchy, and each animal is assigned a specific ranking. While female rank is hereditary--a daughter inherits her mother's status--males compete for dominance. These fights can be bloody, but the stakes are immense: A higher rank means more sex. The losers, in contrast, face a bleak array of options: submission, exile, or death.
In 1978, Robert Sapolsky was a recent college graduate with a biology degree and ajobinKenya.Hehadsetoffforayearof fieldwork by himself among baboons before he returned to the US for grad school and the drudgery of the lab. At the time, Sapol- sky's wilderness experience consisted of short backpacking trips in the Catskill Moun- tains; he had lit a campfire exactly once. Most of what he knew about African wildlife he'd learned from stuffed specimens at the Museum of Natural History. And yet here he was in Nairobi, speaking the wrong kind of Swahili and getting ripped off by everyone he met. Eventually he made his way to the bush, a sprawling savanna filled with zebras and wildebeests and marauding elephants. "I couldn't believe my eyes," Sapolsky remem- bers. "There was an animal behind every tree. I was inside the diorama."

Sapolsky slowly introduced himself to a troop of baboons, letting them adjust to his presence. After a few weeks, he began recog- nizing individual animals, giving them nick- names from the Old Testament. It was a way of rebelling against his childhood Hebrew school teachers, who rejected the blasphemy of Darwinian evolution. "I couldn't wait for the day that I could record in my notebook that Nebuchanezzar and Naomi were off screwing in the bushes," Sapolsky wrote in A Primate's Memoir. "It felt like a pleas- ing revenge."

Before long, Sapolsky's romantic vision of fieldwork collided with the dismal reality of living in the African bush. His feet itched from a fungal infection, his skin was cov- ered in bug bites, the Masai stole his stuff, he had terrible diarrhea, and he was des- perately lonely. Sapolsky's subjects gave him no glimpse of good fellowship. They seemed to devote all of their leisure time--and baboon life is mostly leisure time--to mischief and malevolence. "One of the first things I discovered was that I didn't like baboons very much," he says. "They're quite awful to one another, constantly scheming and backstabbing. They're like chimps but without the self-control."

While Sapolsky was disturbed by the behavior of the baboons--this was nature, red in tooth and claw--he realized that their cruelty presented an opportunity to investi- gate the biological effects of social upheaval. He began to notice, for instance, that the males at the bottom of the hierarchy were thinner and more skittish."They just didn't look very healthy," Sapolsky says. "That's when I began thinking about how damn stressful it must be to have no status. You never know when you're going to get beat up. You never get laid. You have to work a lot harder for food."

And so Sapolsky set out to test the hypothesis that the stress involved in being at the bottom of the baboon hierarchy led to health problems. At the time, stress was mostly ignored as a scientific subject. It was seen as an unpleasant mental state with few long- term consequences. "A couple of studies had linked stress to ulcers, but that was about it," he says. "It struck most doctors as extremely unlikely that your feelings could affect your health. Viruses, sure. Carcinogens, absolutely. But stress? No way." Sapolsky, how- ever, was determined to get some data. He wasn't yet thinking lofty thoughts about human beings or public health. His transformation into one of the leading researchers on the sci- ence of stress would come later. Instead, he was busy learning how to shoot baboons with anesthetic darts and then, while they were plunged into sleep, quickly measure the levels of stress hormones in their blood.

In the decades since, Sapolsky's speculation has become scientific fact. Chronic stress, it turns out, is an extremely dangerous condition. And it's not just baboons: People are just as vulnerable to its effects as those low-ranking male apes. While stress doesn't cause any single disease--ironically, the causal link between stress and ulcers has been largely disproved--it makes most diseases significantly worse. The list of ailments connected to stress is staggeringly diverse and includes everything from the common cold and lower-back pain to Alzheimer's disease, major depressive disorder, and heart attack. Stress hollows out our bones and atrophies our muscles. It triggers adult onset diabetes and is a leading cause of male impotence. In fact, numerous studies of human longevity in developed coun- tries have found that "psychosocial" factors such as stress are the single most important variable in determining the length of a life. It's not that genes and risk factors like smoking don't matter. It's that our levels of stress matter more.

Furthermore, the effects of chronic stress directly counteract improvements in medical care and public health. Antibiotics, for instance, are far less effective when our immune system is suppressed by stress; that fancy heart surgery will work only if the patient can learn to shed stress. As Sapolsky notes, "You can give a guy a drug-coated stent, but if you don't fix the stress problem, it won't really matter. For so many conditions, stress is the major long-term risk factor. Everything else is a short-term fix."

The emergence of stress as a major risk factor is largely a testament to scientific progress: The deadliest diseases of the 21st century are those in which damage accumulates steadily over time. (Sapolsky refers to this as the "luxury of slowly falling apart.") Unfortunately, this is precisely the sort of damage that's exacerbated by emotional stress. While modern medicine has made astonishing progress in treating the fleshy machine of the body, it is only beginning to grapple with those misfortunes of the mind that undo our treatments.

The power of this new view of stress--that our physical health is strongly linked to our emotional state--is that it connects a wide range of scientific observations, from the sociological to the molecular. On one hand, stress can be described as a cultural condition, a byproduct of a society that leaves some people in a permanent state of stress. But that feeling can also be measured in the blood and urine, quantified in terms of glucocorticoids and norepinephrine and adrenal hormones. And now we can see, with scary precision, the devastating cascade unleashed by these chemicals. The end result is that stress is finally being recognized as a critical risk factor, predicting an ever larger percentage of health outcomes.

There's a lot more in the article. Here's one example of how stress destroys the body. Elissa Epel, a former grad student of Sapolsky's and a professor of psychiatry at UCSF, has demonstrated that mothers caring for chronically ill report much higher levels of stress. That's not surprising. What is surprising is that these women also have dramatically shortened telomeres, those caps on the end of chromosomes that keep our DNA from disintegrating. (Women with the highest levels of stress had telomere shortening equal "to at least one decade of additional aging.") When our telomeres run out, our cells stop dividing; we've run out of life. Stress makes us run out of life faster.

the mind is the body

tumor suppression by enriched environment

By (Deric Bownds)

An amazing article by Cao et al. brings home the intimate attachment between mental well-being and health - in mice (and by implication, for us too). An enriched environment promotes formation of a nerve growth factor which in turn inhibits tumor growth through a series of biochemical steps, shown in the summary graphic before the abstract. A commentary by Jonah Lehrer notes that we need "a new metaphor for the interactions of the brain and body. They aren't simply connected via some pipes and tubes. They are emulsified together, so hopelessly intertwined that everything that happens in one affects the other. Holism is the rule."

Cancer is influenced by its microenvironment, yet broader, environmental effects also play a role but remain poorly defined. We report here that mice living in an enriched housing environment show reduced tumor growth and increased remission. We found this effect in melanoma and colon cancer models, and that it was not caused by physical activity alone. Serum from animals held in an enriched environment (EE) inhibited cancer proliferation in vitro and was markedly lower in leptin. Hypothalamic brain-derived neurotrophic factor (BDNF) was selectively upregulated by EE, and its genetic overexpression reduced tumor burden, whereas BDNF knockdown blocked the effect of EE. Mechanistically, we show that hypothalamic BDNF downregulated leptin production in adipocytes via sympathoneural β-adrenergic signaling. These results suggest that genetic or environmental activation of this BDNF/leptin axis may have therapeutic significance for cancer.

Sunday, July 18, 2010

excercise reduces stress

Exercise reduces anxiety and depression

July 14, 2010 via bps

Exercise can ameliorate anxiety and depression-like behaviors induced by an adverse early-life environment by altering the chemistry of the hippocampus, the part of the brain that regulates stress responses, researchers from the University of New South Wales (UNSW) have found.

In the study, rats were divided into groups and either isolated from their mothers for controlled periods of time to induce stress or given normal maternal contact. Half were given access to a running wheel. In addition to being more anxious, animals that were subjected to stress early in life had higher levels of stress hormones and fewer steroid receptors in the part of the brain controlling behaviour.

“Both the anxious behaviour and the levels of hormones in these rats were reversed with access to the exercise wheel,” said UNSW Professor of Pharmacology Margaret Morris.

“We know that exercise can elevate mood, but here we are seeing chemical changes that may underpin this improvement. One of these is increases in brain-derived neurotrophic factor (BDNF), which helps nerve cells grow.

“Many neurological diseases appear to have their origins early in life. Stress hormones affect the way nerve cells grow in the brain. This discovery may be giving us a clue about a different way to tackle a range of conditions that affect mood and behaviour,” she said.

More info: University of New South Wales news

Sunday, July 11, 2010

wealth diminishes ability to savour the ordinary

via derek bownds

Quoidbach et al. test
...what Gilbert has termed the experience-stretching hypothesis, that experiencing the best things in life — such as surfing Oahu’s famous North Shore or dining at Manhattan’s four-star restaurant Daniel — may actually mitigate the delight one experiences in response to the more mundane joys of life, such as sunny days, cold beers, and chocolate bars.
Their abstract:
This study provides the first evidence that money impairs people’s ability to savor everyday positive emotions and experiences. In a sample of working adults, wealthier individuals reported lower savoring ability (the ability to enhance and prolong positive emotional experience). Moreover, the negative impact of wealth on individuals’ ability to savor undermined the positive effects of money on their happiness. We experimentally exposed participants to a reminder of wealth and produced the same deleterious effect on their ability to savor as that produced by actual individual differences in wealth, a result supporting the theory that money has a causal effect on savoring. Moving beyond self-reports, we found that participants exposed to a reminder of wealth spent less time savoring a piece of chocolate and exhibited reduced enjoyment of it compared with participants not exposed to wealth. This article presents evidence supporting the widely held but previously untested belief that having access to the best things in life may actually undercut people’s ability to reap enjoyment from life’s small pleasures.
- - [Technorati] Poemanias Technorati cosmos for Poemanias Wed, 09 Mar 2005 09:48:55 GMT 474652 2 3 Technorati v1.0 - Technorati logo 60 - Mike Snider's Formal Blog and Sonnetarium: "Poemanias" ... Via Poemanias , I've found this tribute site to Michael Donaghy, surely one of the best poets of the late 20th century in English. There's video, audio, and links to poems and transcripts of talks. I met Michael only briefly ...
Mike Snider's Formal Blog and Sonnetarium View Technorati Cosmos
Mon, 07 Mar 2005 21:39:33 GMT 2005-03-07 20:34:58 GMT
- Silliman's Blog: "Edward Farrelly" ... Amanda Drew Joseph Duemer Cliff Duffy Jilly Dybka E Martin Edmond kari edwards Stuart Eglin AnnMarie Eldon Scott Esposito Steve Evans F Roberta Fallon & Libby Rosof (Philly Artblog) Edward Farrelly Rona Fernandez Caterina Fake Ryan Fitzpatrick Jim Flanagan Flarf Debby Florence Juan Jose Flores Paul Ford William Fox Gina Franco Suzanne Frischkorn G Jeannine Hall Gailey C.P. ...
Silliman's Blog View Technorati Cosmos
Mon, 07 Mar 2005 15:48:43 GMT 2005-03-07 14:50:46 GMT