The cognitive strategies humans use to regulate emotions can determine both neurological and physiological responses to potential rewards, a team of New York University and Rutgers University neuroscientists has discovered. The findings, reported in the most recent issue of the journal Nature Neuroscience, shed light on how the regulation of emotions may influence decision making.

Previous research has demonstrated these strategies can alter responses to negative events. However, less understood is whether such strategies can also efficiently regulate expectations of a future reward or a desired outcome. Scientists have already determined that the expectation of a potential reward brings about positive feelings and aids recognizing environmental cues that predict future rewards. Central to this process is the role of the striatum, a multi-faceted structure in the brain that is involved in reward processing–and which is especially engaged when potential rewards are predicted or anticipated.

However, the striatum signal is not always beneficial. Its activity also correlates with drug-specific cravings, most likely increasing urges to partake in risk-seeking behavior in the pursuit of rewards that are detrimental. Therefore, understanding how to regulate or control the positive feelings associated with reward expectation is an important line of inquiry.

The NYU study was conducted by a team of researchers from the laboratory of NYU Professor Elizabeth Phelps, who co-authored the work with Mauricio R. Delgado, now a professor at Rutgers University, and M. Meredith Gillis, an NYU graduate student. They sought to better understand the influence of emotional regulation strategies on the physiological and neural processes relevant to expectations of reward.

The study’s subjects were presented with two conditioned stimuli, a blue and a yellow square that either predicted or did not predict a potential monetary reward. Prior to each trial, participants were also given a written cue that instructed them to either respond to the stimulus (”think of the meaning of the blue square, such as a potential reward”) or regulate their emotional response to the stimulus (”think of something blue in nature that calms you down, such as the ocean”).

Skin conductance responses (SCRs) of the participants were taken at the beginning of each conditioned stimulus. These served as a behavioral measure of physiological reaction potentially related to reward anticipation.

The results showed that the participants’ emotion regulation strategies could influence physiological and neural responses relevant to the expectation of reward. Specifically, results from the SCRs revealed that the subjects’ emotion regulation strategies decreased arousal that was linked to the anticipation of a potential reward.

“Our findings demonstrated that emotion regulation strategies can successfully curb physiological and neural responses associated with the expectation of reward,” said Delgado. “This is a first step to understanding how our thoughts may effectively control positive emotions and eventual urges that may arise, such as drug cravings.”

Nature Neuroscience Published online: 29 June 2008 | doi:10.1038/nn.2141

Brief Communication abstract

Regulating the expectation of reward via cognitive strategies

Mauricio R Delgado, M Meredith Gillis, Elizabeth A Phelps

Previous emotion regulation research has been successful in altering aversive emotional reactions. It is unclear, however, whether such strategies can also efficiently regulate expectations of reward arising from conditioned stimuli, which can at times be maladaptive (for example, drug cravings). Using a monetary reward-conditioning procedure with cognitive strategies, we observed attenuation in both the physiological (skin conductance) and neural correlates (striatum) of reward expectation as participants engaged in emotion regulation.

Thanks to salt and hot chili peppers, researchers have found a calculus-computing center that tells a roundworm to go forward toward dinner or turn to broaden the search.

A spike in salt concentration in ASEL (left neuron) activates expression that leads a worm to proceed in a straight line. A dip in salt levels in ASER (right neuron) turns on a negative reaction that tells a worm to change to a turning movement to look around. (Credit: Graphic courtesy of Shawn Lockery)

These behavior-driving calculations, according to a paper published in the July 3 issue of the journal Nature, are done “in a tiny, specialized computer inside a primitive roundworm,” says principal investigator Shawn Lockery, a University of Oregon biologist and member of the UO Institute of Neuroscience.

In their paper, the researchers documented how two related, closely located chemosensory neurons, acting in tandem, regulate behavior. The left neuron controls an on switch, while the opposing right one an off switch. These sister neurons are situated much like the two nostrils or two eyes of mammals. Together these neurons are known as ASE for antagonistic sensory cues.

It’s possible, Lockery said, that the discovery someday could help research aimed at treating at least some of the 200,000 people in the United States who annually seek medical treatment, according to records of the National Institutes of Health, for problems involving taste and smell.

“This computer does some nice calculus, differentiating the rate of change of the strength of various tastes,” Lockery said. “The worm uses this information to find food and to avoid poisons.”

Lockery and colleagues predicted the existence of a derivative-crunching mechanism in the Journal of Neuroscience in 1999 based on findings that nematodes change directions based on taste and smell.

“In effect, they have two nostrils or two tongues but they are so close together that it is really like having one nostril or one tongue, and yet they find their way around quite effectively,” Lockery said. “We knew from behavioral experiments that nematodes were doing the same thing that humans were doing, but only from the view of behavioral responses. We didn’t know what was going on in the brain.”

To get there, Lockery and colleagues used new imaging and molecular tools, along with some genetic engineering of their worms.

In one experiment, these chemosensory neurons carried a fluorescent protein that changed color based on neuronal activity. In another experiment, the neurons carried receptor proteins that recognize capsaicin, the active component in chili peppers.

Researchers found that when concentrations of salt were high, fluorescent proteins change from blue to yellow, showing that the left neuron (ASEL) was active as the worms continued forward movement. When salt levels were reduced, the right neuron (ASER) activated but generated a different behavior; the worms began a turning, or searching, motion.

“At this point, we wanted to know if these neurons really are controlling behavior. If ASEL really signals that things are getting better, then, if you could artificially activate ASEL the animals ought to go straight like a human going directly toward the pizza,” Lockery said. “Conversely, if you activate the ASER the animals ought to turn to find their goal.”

Such was the case, according to the capsaicin-receptor experiment. When the pepper ingredient was spread on turning worms with receptor proteins in the left neuron, they straightened their motion. Likewise, capsaicin applied to worms with the receptors in their right neurons caused them to change from turning motion to forward crawling.

“We have discovered a tiny, specialized computer inside a primitive round worm,” Lockery said. “The computer calculates the rate of change of the strengths, or concentrations, of various tastes. The worm uses this information to find food and to avoid poisons.”

Evidence for such on and off switching cells in other chemosensory networks of mammals, he added, “There are strong indications that a similar device exists in the human nervous system.”

Nature 454, 114 - 117 (03 Jul 2008), doi: 10.1038/nature06927, Letters to Editor

Functional asymmetry in Caenorhabditis elegans taste neurons and its computational role in chemotaxis

Hiroshi Suzuki, Tod R. Thiele, Serge Faumont, Marina Ezcurra, Shawn R. Lockery, William R. Schafer

Chemotaxis in Caenorhabditis elegans, like chemotaxis in bacteria¹, involves a random walk biased by the time derivative of attractant concentration, but how the derivative is computed is unknown. Laser ablations have shown that the strongest deficits in chemotaxis to salts are obtained when the ASE chemosensory neurons (ASEL and ASER) are ablated, indicating that this pair has a dominant role⁴. Although these neurons are left–right homologues anatomically, they exhibit marked asymmetries in gene expression and ion preference. Here, using optical recordings of calcium concentration in ASE neurons in intact animals, we demonstrate an additional asymmetry: ASEL is an ON-cell, stimulated by increases in NaCl concentration, whereas ASER is an OFF-cell, stimulated by decreases in NaCl concentration. Both responses are reliable yet transient, indicating that ASE neurons report changes in concentration rather than absolute levels. Recordings from synaptic and sensory transduction mutants show that the ON–OFF asymmetry is the result of intrinsic differences between ASE neurons. Unilateral activation experiments indicate that the asymmetry extends to the level of behavioural output: ASEL lengthens bouts of forward locomotion (runs) whereas ASER promotes direction changes (turns). Notably, the input and output asymmetries of ASE neurons are precisely those of a simple yet novel neuronal motif for computing the time derivative of chemosensory information, which is the fundamental computation of C. elegans chemotaxis. Evidence for ON and OFF cells in other chemosensory networks suggests that this motif may be common in animals that navigate by taste and smell.

We all know people who are tense and nervous and can’t relax. They may have been wired differently since childhood.

http://www.leeds.ac.uk/lsmp/healthadvice/Shyness/circleanxiety.jpg

New research by the HealthEmotions Research Institute and Department of Psychiatry at the University of Wisconsin School of Medicine and Public Health (SMPH) indicates that the brains of those suffering from anxiety and severe shyness in social situations consistently respond more strongly to stress, and show signs of being anxious even in situations that others find safe.

Dr. Ned Kalin, chairman of the UW Department of Psychiatry and HealthEmotions Research Institute, in collaboration with graduate student Andrew Fox and others, has published a new study on anxious brains in the online journal PLoS One.

The study looked at brain activity, anxious behaviour, and stress hormones in adolescent rhesus monkeys, which have long been used as a model to understand anxious temperament in human children. Anxious temperament is important because it is an early predictor of the later risk to develop anxiety, depression, and drug abuse related to self medicating.

The researchers found that those individuals with the most anxious temperaments showed higher activity in the amygdala, a part of the brain that regulates emotion and triggers reactions to anxiety, such as the fight or flight response. These anxious monkeys had more metabolic activity in the amygdala in both secure and threatening situations.

“The brain machinery underlying the stress response seems to be always on in these individuals,” said Kalin, “even in situations that others perceive as safe and secure.”

Rhesus monkeys were graded on their anxious temperament, then exposed to situations that ranged from being secure at home with their cage-mates, to being alone, to being confronted by an unfamiliar person. This unknown person stood in front of the monkey presenting her facial profile to the monkey while avoiding any eye contact.

The adolescent monkeys received an injection of FDG, a radioactive substance similar to glucose that lights up the active parts of the brain when the monkeys are imaged with Positron Emission Tomography (PET). Whether in a secure environment or a more uncertain and possibly scary one, the nervous monkeys had more brain activity in the amygdala and surrounding “stress response” parts of the brain. The increased amygdala activity corresponded to higher levels of “freezing” behaviour, fewer vocalizations and higher levels of the stress hormone cortisol in the anxious monkeys.

When the monkeys were retested a year and a half later, the results were the same: the anxious monkeys still were more stressed out than their calmer peers when judged by the behavioural and physiological measures.

“We’re looking for better ways to diagnose and treat mental illness,” explains Kalin, about his ongoing work at HealthEmotions. “We’re trying to understand how the brain influences mood, reactions to stress and physical health.”

Psychiatrists have long known that an anxious temperament in childhood is a risk factor for developing anxiety disorders, depression and substance abuse. These new findings in young rhesus monkeys point to a brain mechanism that is present early in life that predisposes to this disposition.

The current research suggests that the reason is it is hard for some one with an anxious temperament to “calm down” is because they are wired in a way that tends to keep them tense and anxious.

PLoS ONE 3(7): e2570. doi:10.1371/journal.pone.0002570

Trait-Like Brain Activity during Adolescence Predicts Anxious Temperament in Primates.

Fox AS, Shelton SE, Oakes TR, Davidson RJ, Kalin NH (200

Early theorists (Freud and Darwin) speculated that extremely shy children, or those with anxious temperament, were likely to have anxiety problems as adults. More recent studies demonstrate that these children have heightened responses to potentially threatening situations reacting with intense defensive responses that are characterized by behavioral inhibition (BI) (inhibited motor behavior and decreased vocalizations) and physiological arousal. Confirming the earlier impressions, data now demonstrate that children with this disposition are at increased risk to develop anxiety, depression, and comorbid substance abuse. Additional key features of anxious temperament are that it appears at a young age, it is a stable characteristic of individuals, and even in non-threatening environments it is associated with increased psychic anxiety and somatic tension. To understand the neural underpinnings of anxious temperament, we performed imaging studies with 18-fluoro-deoxyglucose (FDG) high-resolution Positron Emission Tomography (PET) in young rhesus monkeys. Rhesus monkeys were used because they provide a well validated model of anxious temperament for studies that cannot be performed in human children. Imaging the same animal in stressful and secure contexts, we examined the relation between regional metabolic brain activity and a trait-like measure of anxious temperament that encompasses measures of BI and pituitary-adrenal reactivity. Regardless of context, results demonstrated a trait-like pattern of brain activity (amygdala, bed nucleus of stria terminalis, hippocampus, and periaqueductal gray) that is predictive of individual phenotypic differences. Importantly, individuals with extreme anxious temperament also displayed increased activity of this circuit when assessed in the security of their home environment. These findings suggest that increased activity of this circuit early in life mediates the childhood temperamental risk to develop anxiety and depression. In addition, the findings provide an explanation for why individuals with anxious temperament have difficulty relaxing in environments that others perceive as non-stressful.

Researchers have found a possible way to overcome the common problem of dieters eventually abandoning their diet and regaining the weight they lost. Eat a big breakfast packed with carbohydrates (”carbs”) and protein, then follow a low-carb, low-calorie diet the rest of the day, the authors of a new study recommend.

“Most weight loss studies have determined that a very low carbohydrate diet is not a good method to reduce weight,” said lead author Daniela Jakubowicz, MD, of the Hospital de Clinicas, Caracas, Venzezuela. “It exacerbates the craving for carbohydrates and slows metabolism. As a result, after a short period of weight loss, there is a quick return to obesity.”

Only five percent of carbohydrate-restrictive diets are successful after two years, Jakubowicz said. Most carbohydrate-restrictive diets, she said, do not address addictive eating impulses.

With scientists from Virginia Commonwealth University in Richmond, Jakubowicz and her colleagues conducted a study, which they said shows that a diet’s long-term effectiveness depends on its ability to increase a sense of fullness and bring down carb cravings. They compared their new diet with a strict low-carb diet in 94 obese, physically inactive women. Both diets were low in fat and total calories but differed in the carbohydrate distribution.

Forty-six women were on the very-low-carb diet, which allowed them to eat 1,085 calories a day. The diet consisted of 17 grams of carbohydrates, 51 grams of protein and 78 grams of fat a day. The smallest meal was breakfast, at 290 calories. For breakfast the dieters were permitted only 7 grams of carbohydrates, such as bread, fruit, cereal and milk. Dieters could eat just 12 grams of protein, such as meat and eggs, in the morning.

On the modified low-carb diet, or “big-breakfast diet,” the other 48 dieters ate 1,240 calories a day. Although lower in total fat (46 grams) than the other diet, the new diet had higher daily allotments of carbs (97 grams) and protein (93 grams). Dieters ate a 610-calorie big breakfast, consisting of 58 grams of carbs, 47 grams of protein and 22 fat grams. The diet schedule for lunch was 395 calories (34, 28 and 13 grams of carbs, protein and fat, respectively); dinner was 235 calories (5, 18 and 26 grams, respectively).

The first half of the eight-month study focused on weight loss, and the last four months on weight maintenance. At four months, the women on the strict low-carb diet dropped an average of about 28 pounds, and the women on the big-breakfast diet lost nearly 23 pounds on average, which according to Jakubowicz was not significantly different. But at 8 months, the low-carb dieters regained an average of 18 pounds, while the big-breakfast group continued to lose weight, shedding another 16.5 pounds. Those on the new diet lost more than 21 percent of their body weight, compared with just 4.5 percent for the low-carb group. Furthermore, the study found that women who ate a big breakfast reported feeling less hungry, especially before lunch, and having fewer cravings for carbs than the other women did.

Jakubowicz said the big-breakfast diet works because it controls appetite and cravings for sweets and starches. It also is healthier than an extremely low-carbohydrate diet, according to Jakubowicz, because it allows people to eat more fruit and therefore get enough fiber and vitamins. She said she has successfully used the diet in her patients for more than 15 years.

Results were presented Tuesday, June 17, at The Endocrine Society’s 90th Annual Meeting in San Francisco.

[P3-220] Effect of Diet with High Carbohydrate and Protein Breakfast on Weight Loss and Appetite in Obese Women with Metabolic Syndrome.

D Jakubowicz, D Maman, P Essah, Hosp de Clins Caracas, Caracas, Venezuela; Med Coll of Virginia, Virginia Commonwealth Univ, Richmond, VA

Background: Insulin resistance, common in obesity, promotes weight gain. Weight loss diets for obesity are frequently unsuccessful due to a carbohydrate withdrawal effect that exacerbates carbohydrate craving and hunger. We hypothesized that a diet aimed at reducing hunger and carbohydrate craving would support weight loss in obese individuals.
Objective: The purpose of this study was to determine whether a diet consisting of a high carbohydrate and protein breakfast would promote weight loss, increase satiety, and reduce carbohydrate craving in obese women with metabolic syndrome.
Methods: In this 32-week prospective study, 94 obese sedentary women (age 31.67yrs, BMI 33.84kg/m2) with metabolic syndrome were randomized to one of two diets: 1) a strict low carbohydrate diet (LCH; n=46) consisting of 1085kc/day (carb:protein:fat 17:51:78g) with breakfast 290kc (7:12:24g), lunch 425kc (5:21:28g), and dinner 370 kc (5:18:26g) or 2) a LCH diet with the modification of a high carbohydrate and protein big breakfast (LCH+BB;n=4 consisting of 1240kc, (carb:protein:fat 97:93:46g) with breakfast 610kc (58:47:22g), lunch 395kc, (34:28:13g),and dinner 235kc (5:18:11g). The first 16wks aimed on weight loss and the last 16 weeks on weight maintenance (WM). A 3-h meal tolerance test (MTT) was performed with quantification of glucose, insulin and appetite scores (hunger, satiety, fullness, and desire to eat) using 100-mm visual analog scales (VAS) at 0, 30, 60, 120, and 180 min after LCH or LCH+BB breakfast.
Results: Both groups lost weight at 16 wks (LCH: -12.62kg, LCH+BB: -10.63kg, p=NS). During the WM phase, the LCH+BB group continued to lose weight (-7.52kg, p<0.001 vs. 16 wk) whereas the LCH group gained weight (+8.32kg, p<0.001 vs. 16 wk). At 32 wks, the LCH group lost 4.5% of their baseline weight. In contrast, the LCH+BB group decreased baseline weight by 21.3%. AUC for glucose and insulin responses to MTT improved in line with weight loss (p<0.001, NS between groups). Compared with LCH, LCH+BB reduced hunger (p=0.02), increased satiety (p=0.07), decreased desire to eat (p=0.02), and increased fullness immediately prior to lunch (p<0.001). In contrast to LCH, LCH+BB reduced carbohydrate craving scores (P<0.001).
Conclusion: A diet consisting of a high carbohydrate and protein breakfast facilitates weight loss by reducing hunger and diminishing carbohydrate craving. Effective weight loss strategies for obese individuals should focus on controlling appetite and carbohydrate craving.

Date: Tuesday, June 17, 2008

Session Info: POSTER SESSION: CLINICAL - Assessment Treatment Outcomes for Obesity (11:00 AM-12:00 PM 2:30 PM-3:45 PM)

Presentation Time: 11:00 AM

Room: Exhibit Halls B/C

Unless otherwise noted, all abstracts are embargoed until the time of their presentation at ENDO 08. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to the start of ENDO 08. For additional information, please contact The Endocrine Society’s Public Affairs department at 301-941-0240 or cblue@endo-society.org.

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The quality of life of adolescents who think they are too fat is worse than for adolescents who really are obese. This was a result of the all Germany Health Interview and Examination Survey for Children and Adolescents (KiGGS) of the Robert Koch Institute, as presented by Bärbel-Maria Kurth and Ute Ellert in the current edition of Deutsches Ärzteblatt International.

KiGGS study, almost 7000 boys and girls aged between 11 and 17 years were weighed and asked about their self-assessment, ranging from “far too thin” to “far too fat.” In addition, they all completed a questionnaire about quality of life. As a result of their analysis, the scientists established that about three quarters of adolescents are of normal weight. Almost 55% of the girls, but just under 36% of the boys thought that they were “too fat,” although only about 18% of the adolescents were actually overweight. 7% to 8% of the adolescents were underweight.

The quality of life is lower in obese adolescents. However, this correlates to a large extent with self-evaluation. If adolescents think they are “far too fat,” they forfeit a lot of their quality of life, whatever their actual weight. This is particularly marked with girls. On the other hand, if they consider their weight “just right,” their quality of life is the same as if they were of normal weight, even if this is not true. The proportion of adolescents who think they are overweight has been increasing more rapidly in recent years than the proportion of those who really are overweight.

In an accompanying editorial, Johannes Hebebrand points out that adolescents are exposed to considerable social pressure to be thin. He thinks that it is remarkable that as many as 40% of the subjects thought that their weight was right, in spite of the ideal of slimness and the stigma of being overweight.

Dtsch Arztebl Int 2008; 105(23): 406–12 DOI: 10.3238/arztebl.2008.0406

Perceived or True Obesity: Which Causes Min Adolescents?

Bärbel-Maria Kurth and Ute Ellert. 

SUMMARY
Introduction: The consequences of perceived obesity on quality of life are compared with those of genuine obesity in adolescents.
Methods: Within the framework of the German Health Interview and Examination Survey for Children and
Adolescents (KiGGS), the height and weight of the participants were measured. Children over 11 years of age
were asked whether they thought of themselves as underweight, normal, or overweight. As a measure of their health-related quality of life they completed the internationally employed KINDL-R generic questionnaire.
Results: While 74.8% of 11- to 17-year-old girls and boys are of normal weight, only 40.4% believe that they are just the right weight.“ Only 60.9% of obese girls and 32.2% of obese boys think of themselves as overweight. The data showed that genuinely obese adolescents, as classified by body mass index, have a better quality of life than those who only perceive themselves as being overweight.
Discussion: A realistic body image on the part of obese adolescents is a prerequisite for their acceptance of interventions. The marked deterioration in quality of life resulting from perceived obesity, even for young people of normal weight, illustrates the complexity of the struggle against obesity.

New research at UT Southwestern Medical Center may explain why some people who are stressed or depressed overeat. While levels of the so-called “hunger hormone” ghrelin are known to increase when a person doesn’t eat, findings by UT Southwestern scientists suggest that the hormone might also help defend against symptoms of stress-induced depression and anxiety.

“Our findings in mice suggest that chronic stress causes ghrelin levels to go up and that behaviors associated with depression and anxiety decrease when ghrelin levels rise. An unfortunate side effect, however, is increased food intake and body weight,” said Dr. Jeffrey Zigman, assistant professor of internal medicine and psychiatry at UT Southwestern and senior author of a study appearing online today and in a future print edition of Nature Neuroscience.

Dr. Michael Lutter, instructor of psychiatry at UT Southwestern and lead author of the study, said, “Our findings support the idea that these hunger hormones don’t do just one thing; rather, they coordinate an entire behavioral response to stress and probably affect mood, stress and energy levels.”

It is known that fasting causes ghrelin to be produced in the gastrointestinal tract, and that the hormone then plays a role in sending hunger signals to the brain. Research groups including Dr. Zigman’s have suggested that blocking the body’s response to ghrelin signals might be one way to help control weight by decreasing food intake and increasing energy expenditure.

“However, this new research suggests that if you block ghrelin signaling, you might actually increase anxiety and depression, which would be bad,” Dr. Zigman said.

To determine how ghrelin affects mood, Dr. Zigman and his colleagues restricted the food intake of laboratory mice for 10 days. This caused their ghrelin levels to quadruple. As compared to the control mice, which were allowed free access to food, the calorie-restricted mice displayed decreased levels of anxiety and depression when subjected to mazes and other standard behavior tests for depression and anxiety.

In addition, mice genetically engineered to be unable to respond to ghrelin were also fed a restricted-calorie diet. Unlike their calorie-restricted wild-type counterparts, these mice did not experience the antidepressant-like or anti-anxiety-like effects.

To test whether ghrelin could regulate depressive symptoms brought on by chronic stress, the researchers subjected mice to daily bouts of social stress, using a standard laboratory technique that induces stress by exposing normal mice to very aggressive “bully” mice. Such animals have been shown to be good models for studying depression in humans.

The researchers stressed both wild-type mice and altered mice that were unable to respond to ghrelin. They found that after experiencing stress, both types of mice had significantly elevated levels of ghrelin that persisted at least four weeks after their last defeat encounter. The altered mice, however, displayed significantly greater social avoidance than their wild-type counterparts, indicating an exacerbation of depression-like symptoms. They also ate less than the wild-type mice.

Dr. Zigman said the findings make sense when considered from an evolutionary standpoint.

Until modern times, the one common human experience was securing enough food to prevent starvation. Our hunter-gatherer ancestors needed to be as calm and collected as possible when it was time to venture out in search of food, or risk becoming dinner themselves, Dr. Zigman said, adding that the anti-anxiety effects of hunger-induced ghrelin may have provided a survival advantage.

Dr. Lutter said the findings might be relevant in understanding conditions such as anorexia nervosa.

“We’re very interested to see whether ghrelin treatment could help people with anorexia nervosa, with the idea being that in a certain population, calorie restriction and weight loss could have an antidepressant effect and could be reinforcing for this illness,” Dr. Lutter said.

In future studies, the researchers hope to determine which area in the brain ghrelin may be acting on to cause these antidepressant-like effects.

Nature Neuroscience (15 Jun 2008), doi: 10.1038/nn.2139, Brief Communications

We found that increasing ghrelin levels, through subcutaneous injections or calorie restriction, produced anxiolytic- and antidepressant-like responses in the elevated plus maze and forced swim test. Moreover, chronic social defeat stress, a rodent model of depression, persistently increased ghrelin levels, whereas growth hormone secretagogue receptor (Ghsr) null mice showed increased deleterious effects of chronic defeat. Together, these findings demonstrate a previously unknown function for ghrelin in defending against depressive-like symptoms of chronic stress.

Drink coffee to send a wake-up call to the brain? Or just smell its rich, warm aroma? An international group of scientists is reporting some of the first evidence that simply inhaling coffee aroma alters the activity of genes in the brain.

In experiments with laboratory rats, they found that coffee aroma orchestrates the expression of more than a dozen genes and some changes in protein expressions, in ways that help reduce the stress of sleep deprivation.

Han-Seok Seo and colleagues point out that hundreds of studies have been done on the ingredients in coffee, including substances linked to beneficial health effects. “There are few studies that deal with the beneficial effects of coffee aroma,” they note. “This study is the first effort to elucidate the effects of coffee bean aroma on the sleep deprivation-induced stress in the rat brain.”

In an effort to begin filling that gap, they allowed lab rats to inhale coffee aroma, including some rats stressed by sleep deprivation. The study then compared gene and protein expressions in the rats’ brains. Rats that sniffed coffee showed different levels of activity in 17 genes. Thirteen of the genes showed differential mRNA expression between the stress group and the stress with coffee group, including proteins with healthful antioxidant activity known to protect nerve cells from stress-related damage.

ASAP J. Agric. Food Chem., ASAP Article, 10.1021/jf8001137
Web Release Date: June 3, 2008

The aim of this study was 2-fold: (i) to demonstrate influences of roasted coffee bean aroma on rat brain functions by using the transcriptomics and proteomics approaches and (ii) to evaluate the impact of roasted coffee bean aroma on stress induced by sleep deprivation. The aroma of the roasted coffee beans was administered to four groups of adult male Wistar rats: 1, control group; 2, 24 h sleep deprivation-induced stress group (the stress group); 3, coffee aroma-exposed group without stress (the coffee group); and 4, the stress with coffee aroma group (the stress with coffee group). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of some known genes responsive to aroma or stress was performed using total RNA from these four groups. A total of 17 selected genes of the coffee were differently expressed over the control. Additionally, the expression levels of 13 genes were different between the stress group and the stress with coffee group: Up-regulation was found for 11 genes, and down-regulation was seen for two genes in the stress with coffee group. We also looked to changes in protein profiles in these four samples using two-dimensional (2D) gel electrophoresis; 25 differently expressed gel spots were detected on 2D gels stained by silver nitrate. Out of these, a total of nine proteins were identified by mass spectrometry. Identified proteins belonged to five functional categories: antioxidant; protein fate; cell rescue, defense, and virulence; cellular communication/signal transduction mechanism; and energy metabolism. Among the differentially expressed genes and proteins between the stress and the stress with coffee group, NGFR, trkC, GIR, thiol-specific antioxidant protein, and heat shock 70 kDa protein 5 are known to have antioxidant or antistress functions. In conclusion, the roasted coffee bean aroma changes the mRNA and protein expression levels of the rat brain, providing for the first time clues to the potential antioxidant or stress relaxation activities of the coffee bean aroma.

Coffee’s Aroma Kick-starts Genes In The Brain

ScienceDaily (Jun. 16, 200 — Drink coffee to send a wake-up call to the brain? Or just smell its rich, warm aroma? An international group of scientists is reporting some of the first evidence that simply inhaling coffee aroma alters the activity of genes in the brain.

In experiments with laboratory rats, they found that coffee aroma orchestrates the expression of more than a dozen genes and some changes in protein expressions, in ways that help reduce the stress of sleep deprivation.

Han-Seok Seo and colleagues point out that hundreds of studies have been done on the ingredients in coffee, including substances linked to beneficial health effects. “There are few studies that deal with the beneficial effects of coffee aroma,” they note. “This study is the first effort to elucidate the effects of coffee bean aroma on the sleep deprivation-induced stress in the rat brain.”

In an effort to begin filling that gap, they allowed lab rats to inhale coffee aroma, including some rats stressed by sleep deprivation. The study then compared gene and protein expressions in the rats’ brains. Rats that sniffed coffee showed different levels of activity in 17 genes. Thirteen of the genes showed differential mRNA expression between the stress group and the stress with coffee group, including proteins with healthful antioxidant activity known to protect nerve cells from stress-related damage.

ASAP J. Agric. Food Chem., ASAP Article, 10.1021/jf8001137
Web Release Date: June 3, 2008

The aim of this study was 2-fold: (i) to demonstrate influences of roasted coffee bean aroma on rat brain functions by using the transcriptomics and proteomics approaches and (ii) to evaluate the impact of roasted coffee bean aroma on stress induced by sleep deprivation. The aroma of the roasted coffee beans was administered to four groups of adult male Wistar rats: 1, control group; 2, 24 h sleep deprivation-induced stress group (the stress group); 3, coffee aroma-exposed group without stress (the coffee group); and 4, the stress with coffee aroma group (the stress with coffee group). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of some known genes responsive to aroma or stress was performed using total RNA from these four groups. A total of 17 selected genes of the coffee were differently expressed over the control. Additionally, the expression levels of 13 genes were different between the stress group and the stress with coffee group: Up-regulation was found for 11 genes, and down-regulation was seen for two genes in the stress with coffee group. We also looked to changes in protein profiles in these four samples using two-dimensional (2D) gel electrophoresis; 25 differently expressed gel spots were detected on 2D gels stained by silver nitrate. Out of these, a total of nine proteins were identified by mass spectrometry. Identified proteins belonged to five functional categories: antioxidant; protein fate; cell rescue, defense, and virulence; cellular communication/signal transduction mechanism; and energy metabolism. Among the differentially expressed genes and proteins between the stress and the stress with coffee group, NGFR, trkC, GIR, thiol-specific antioxidant protein, and heat shock 70 kDa protein 5 are known to have antioxidant or antistress functions. In conclusion, the roasted coffee bean aroma changes the mRNA and protein expression levels of the rat brain, providing for the first time clues to the potential antioxidant or stress relaxation activities of the coffee bean aroma.

Many of us experience a tinge of guilt as we delight in feelings of pleasure from our favorite indulgences, like splurging on an expensive handbag or having another drink. We make resolutions: this will be the last time, positively.

Yet, in spite of documented ambivalence towards temptation and well-meaning vows not to succumb again, consumers often end up repeating the same or similar choices. A new study by Suresh Ramanathan (University of Chicago) and Patti Williams (Wharton School of Business, University of Pennsylvania) examines repeated impulsive behavior despite the presence of guilt — important research underscored by the increasing prevalence of binge drinking, obesity, and credit card debt.

While most published research has examined the emotional consequences of self-control lapses, Ramanathan and Williams expand the literature by studying the affective outcomes of indulgent consumption as it unfolds over time. In two studies, they examine the immediate and delayed emotional consequences of engaging in indulgent consumption among both prudent and impulsive consumers.

Significantly, the researchers find that both impulsive and prudent consumers experience a mixture of positive and negative emotions immediately after consuming a food indulgence. However, the components of the emotional ambivalence are different across the two groups.

“While the impulsive consumers do feel negative emotions such as stress, they do not feel much guilt or regret,” the authors reveal.

Further, the time course of these emotions is different across the two types of consumers. Impulsive people continue to feel residual effects of their positive emotions over time, but experience a sharp decline in their negative emotions. Prudent people continue to experience strong negative and self-conscious emotions, but report significantly lower levels of positive emotions.

“Thus, over time, impulsive consumers are left only with their positive feelings about indulging, while prudent consumers are left only with their negative feelings about indulging. This, in turn, affects propensity to repeat an act of indulgence,” the authors explain.

Therefore, impulsive consumers are much more likely to engage in a second indulgent act over time than are prudent consumers. The authors also find differences in the extent to which people take actions to undo their emotional ambivalence. After indulging once, prudent consumers are more likely than impulsive consumers to seize an opportunity to make a utilitarian choice.

“Impulsive people may be more comfortable with duality or conflict, or may be more resigned to the experience of such conflict,” the authors conclude. “Prudent people, on the other hand, seem to be more eager to seize the chance to launder their negative emotions.”

JOURNAL OF CONSUMER RESEARCH, Inc. • Vol. 34 • August 2007

The majority of literature looking at self-control dilemmas has focused on short-term positive and long-term negative affective outcomes arising from indulgence. In two studies, we find evidence for more complex emotional responses after indulgent consumption. We show that consumers feel simultaneous mixtures of both positive and negative emotions in response to indulgences and that the specific components of those emotional mixtures vary, depending on differences in individual impulsivity. Further, these mixtures are resolved differently over time, leading to differences in subsequent choices. In addition we show that more prudent consumers are likely to seize an opportunity to get rid of, or “launder,” their negative emotions after an indulgence by subsequently making utilitarian versus hedonic choices.

Reckless decision-making can lead to dire consequences when it comes to food, credit cards, or savings. What’s the key to making good decisions? A new study in the Journal of Consumer Research outlines a novel method for measuring people’s abilities to consider the consequences of their actions. It also provides hope for consumers who want to make more prudent decisions.

Authors Gergana Y. Nenkov (Boston College), J. Jeffrey Inman, and John Hulland (both University of Pittsburgh) developed a 13-question survey that rated participants on a scale called the Elaboration on Potential Outcomes (EPO) scale. The scale proved to be a reliable measure of how much participants considered the consequences of their actions. For example, when undergraduates considered whether to get LASIK surgery or whether to charge an expensive electronics item on an already heavily charged credit card, high EPO scores were associated with more consequence-related thoughts.

In a number of settings, researchers found that consumers who think about the pros and cons before making decisions reported that they were more likely to exercise and consume healthy foods. They had lower rates of alcohol abuse, procrastination, and overspending. They were also more likely to be saving money for retirement.

The good news, according to the authors, is that people who aren’t inclined to consider the consequences of their actions can be aided by simple interventions, like brochures and advertising that encourage them to think about the dangers of obesity or the benefits of saving for retirement. Scare tactics, it seems, were the most effective. “The consideration of negative consequences has a bigger impact than the consideration of positive consequences,” the authors write.

This somehow contradicts Bandura’s well proven model of behavioral change, where negative consequences correlate less then half as much as self efficacy and situation outcome expectancies when it comes to successful decision for a behavioral change. It seems like decision making is not the same in consumption or eating behaviour, and the extension of findings in marketing research to experimental psychology is obviously a slippery slope.

“The importance of studying consumers’ self-control is widely recognized, since being unable to regulate one’s emotions, impulses, actions and thoughts creates problems, not only for individual consumers, but also for society as a whole,” write the authors, hopefully not another slippery slope towards consumer manipulation…

JOURNAL OF CONSUMER RESEARCH, Inc. • Vol. 35 • June 2008

Considering the Future: The Conceptualization and Measurement of Elaboration on Potential Outcomes
Gergana Y. Nenkov, J. Jeffrey Inman, and John Hulland

We examine a new construct dealing with individuals’ tendency to elaborate on potential outcomes, that is, to generate and evaluate potential positive and negative consequences of their behaviors. We develop the elaboration on potential outcomes (EPO) scale and then investigate its relationships with conceptually related traits and its association with consumer behaviors such as exercise of self-control, procrastination, compulsive buying, credit card debt, retirement investing, and healthy lifestyle. Finally, we show that consumers with high EPO levels exhibit more effective self-regulation when faced with a choice and that EPO can be primed, temporarily improving self-regulation for consumers with low EPO levels.