Can people's differing reactions to situations of stress be attributed at least in part to genetic differences and do those differences affect men and women in different ways - with the edge seemingly favoring the women? Research conducted at the Hebrew University of Jerusalem would seem to indicate that the answer to both questions is yes. Reaction to stress traced to genetic differences
Some people appear to be resilient to difficult conditions, whereas others react adversely to such challenges, incurring a range of physical and mental disorders. Much research has shown that the way in which the brain and body adapt to acute and chronic stress are critical for physical and mental health. Further, according to a recent report by the World Health Organization (WHO), stress will be the second leading cause of mortality worldwide over the next 20 years.
It is generally believed that the genetic code plays a prominent role in different responses to stress. It has been estimated that the heredity factor determines by some 62 percent the level of the stress hormone (cortisol) in our bodies. However, only a handful of investigations so far have documented the role of specific genetic variants on shaping the stress response among individuals.
In an effort to reveal a genetic basis for coping with stress, the Hebrew University researchers devised a laboratory-based social stress test. The trials were carried out on students at the Hebrew University Department of Psychology and at the Aaron Beare Research Laboratories at Herzog Hospital by Idan Shalev, a doctoral student of Hebrew University Psychology Prof. Richard Ebstein, and in collaboration with Dr. Marsha Kaitz of the Department of Psychology. The results were published recently online in the journal Psychoneuroendocrinology.
In the test, the researchers examined the salivary cortisol response in 97 university students via the Trier Social Stress Test (TSST) devised at Trier University in Germany. The TSST measures changes in salivary cortisol to assess stress reactivity to challenging social situations.
The students were told that they would play the role of an interviewee for a job and had five minutes to convince the interviewers to hire them. The interview was carried out with a microphone and camera in front of a panel of three straight-faced judges. Additionally, in a second phase of the interview, subjects were tested in a mental arithmetic task in which they were asked to count backwards (out loud) from 1,687 in multiples of 13 as quickly and accurately as possible. If the subject made a mistake he or she was asked to start the series again.
In addition to testing the cortisol level, mouthwash samples were taken and subjects were genotyped for the brain-derived neurotrophic factor (BDNF) gene, which is involved in supporting the growth and differentiation of brain cells. Importantly, animal studies show that BDNF expression is reduced in chronic stress and restored by antidepressant treatment.
The BDNF gene is characterized by a variant that codes for either the valine (Val) or methionine (Met) amino acids. Individuals carry two copies of each gene, with the Val variant being more common. In the study, subjects carrying two copies of the VAL variant (Val/Val), were compared in their cortisol response to those carrying one copy of the Val and one of the Met (Val/Met).
When looking at the responses of the subjects in the stress testing, it was seen that the Val/Met men and women carriers had nearly equal cortisol levels. However, the men with the Val/Val variant had a higher cortisol response (and therefore a higher reaction to social stress) than the men carrying the Val/Met variant. For the women, surprisingly, the opposite was found: the Val/Val women had a lower cortisol response than the Val/Met women. Why the Val/Val variant produces opposite stress reactions (raising it for the males and lowering it for the females) remains an enigma.
Because of the predominance of the Val/Val type for both sexes, the males showed overall greater stress in the testing than the females.
The Hebrew University researchers point out that their investigation shows the importance of genotyping as an aid in helping to resolve paradoxical observations related to stress-related sex differences and also in providing new insight into understanding how depression and other psycho-neurological illnesses may be the result of a combination of stressful life events and genetic factors.
In conclusion, say the researchers, the study specifically indicates that women with the BDNF Val/Met genotype and men with the Val/Val may be particularly vulnerable to social stress mediated by brain stress system activity.
“You wait till Larry comes and I tell him my theory!” The bids, duly sealed, were given into the keeping of the commissary officer to be put in his safe, and kept until the day of judgment, when all being opened in public and in the presence of the aspirants, the lowest would[Pg 188] get the contract. It was a simple plan, and gave no more opportunity for underhand work than could be avoided. But there were opportunities for all that. It was barely possible—the thing had been done—for a commissary clerk or sergeant, desirous of adding to his pittance of pay, or of favoring a friend among the bidders, to tamper with the bids. By the same token there was no real reason why the commissary officer could not do it himself. Landor had never heard, or known, of such a case, but undoubtedly the way was there. It was a question of having the will and the possession of the safe keys. "Well, I believe our boys 's all right. They're green, and they're friskier than colts in a clover field, but they're all good stuff, and I believe we kin stand off any ordinary gang o' guerrillas. I'll chance it, anyhow. This's a mighty valuable train to risk, but it ought to go through, for we don't know how badly they may need it. You tell your engineer to go ahead carefully and give two long whistles if he sees anything dangerous." "Fine-looking lot of youngsters," he remarked. "They'll make good soldiers." "That's just what he was, the little runt, and we had the devil's own time finding him. What in Sam Hill did the Captain take him for, I'd like to know? Co. Q aint no nursery. Well, the bugler up at Brigade Headquarters blowed some sort of a call, and Skidmore wanted to know what it meant. They told him that it was an order for the youngest man in each company to come up there and get some milk for his coffee tomorrow morning, and butter for his bread. There was only enough issued for the youngest boys, and if he wanted his share he'd have to get a big hustle on him, for the feller whose nose he'd put out o' joint 'd try hard to get there ahead o' him, and get his share. So Skidmore went off at a dead run toward the sound of the bugle, with the boys looking after him and snickering. But he didn't come back at roll-call, nor at tattoo, and the smart Alecks begun to get scared, and abuse each other for setting up a job on a poor, innocent little boy. Osc Brewster and Ol Perry, who had been foremost in the trick had a fight as to which had been to blame. Taps come, and he didn't get back, and then we all became scared. I'd sent Jim Hunter over to Brigade Headquarters to look for him, but he came back, and said they hadn't seen anything of him there. Then I turned out the whole company to look for him. Of course, them too-awfully smart galoots of Co. A had to get very funny over our trouble. They asked why we didn't get the right kind of nurses for our company, that wouldn't let the members stray out of their sight? Why we didn't call the children in when the chickens went to roost, undress 'em, and tuck 'em in their little beds, and sing to 'em after they'd said 'Now I lay me down to sleep?' I stood it all until that big, hulking Pete Nasmith came down with a camp-kettle, which he was making ring like a bell, as he yelled out, 'Child lost! Child lost!' Behind him was Tub Rawlings singing, 'Empty's the cradle, baby's gone.' Then I pulled off my blouse and slung it into my tent, and told 'em there went my chevrons, and I was simply Scott Ralston, and able to lick any man in Co. A. One o' their Lieutenants came out and ordered them back to their quarters, and I deployed the company in a skirmish-line, and started 'em through the brush toward Brigade Headquarters. About three-quarters o' the way Osc Brewster and Ol Perry, when going through a thicket, heard a boy boo-hooing. They made their way to him, and there was little Skidmore sitting on a stump, completely confused and fagged out. He'd lost his way, and the more he tried to find it the worse he got turned around. They called out to him, and he blubbered out: 'Yes, it's me; little Pete Skidmore. Them doddurned fools in my company 've lost me, just as I've bin tellin' 'em right along they would, durn 'em.' Osc and Ol were so tickled at finding him that they gathered him up, and come whooping back to camp, carrying him every step of the way." And the rush stopped. Cadnan waited for a second, but there was no more. "Dara is not to die," he said. Then he saw Orion hanging over him, very low in the windy sky, shaking with frost. His eyes fixed themselves on the constellation, then gradually he became aware of the sides of a cart, of the smell of straw, of the movement of other bodies that sighed and stirred beside him. The physical experience was now complete, and soon the emotional had shaped itself. Memory came, rather sick. He remembered the fight, his terror, the flaming straw, the crowd that constricted and crushed him like a snake. His rage and hate rekindled, but this time without focus—he hated just everyone and everything. He hated the wheels which jolted him, his body because it was bruised, the other bodies round him, the stars that danced above him, those unknown footsteps that tramped beside him on the road. Farewell to Jane and Caroline!" HoME大香蕉色人阁 ENTER NUMBET 0017
Refs
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Liberal Eugenics
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The End of Suffering
Wirehead Hedonism
The Good Drug Guide
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
MDMA: Utopian Pharmacology
Transhumanism: Brave New World?
Critique of Aldous Huxley's Brave New World
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