Prefrontal cortex, obesity, appetite

Tobacco smoke during gestation is associated with increased consumption of palatable foods by the offspring in humans and rats. Postpartum relapse is observed in lactating women who quit smoking during pregnancy, putting their children at risk of adverse health outcomes caused by secondhand smoke. Nicotine is transferred through milk and alters the dopaminergic reward system of adult male rats, reducing dopamine action in the nucleus accumbens (NAc) and hypothalamic arcuate nucleus. Here, we evaluated the long-term effects of nicotine-only exposure during lactation on eating behavior, anxiety, locomotion, dopaminergic system, hypothalamic leptin signaling and nicotinic receptor in the adult female rat progeny...

Abnormal activities in reward-related regions are associated with overeating or obesity. Preliminary studies have shown that changes in neural activity in obesity include not only regional reward regions abnormalities but also impairments in the communication between reward-related regions and multiple functional areas. A recent study has shown that the transitions between different neural networks are nonrandom and hierarchical, and that activation of particular brain networks is more likely to occur after other brain networks...

The biological mediators that support cognitive-control and long-term weight-loss after laparoscopic sleeve gastrectomy (LSG) remain unclear. We measured peripheral appetitive hormones and brain functional-connectivity (FC) using magnetic-resonance-imaging with food cue-reactivity task in 25 obese participants at pre, 1 month, and 6 month after LSG, and compared with 30 normal weight controls. We also used diffusion-tensor-imaging to explore whether LSG increases brain structural-connectivity (SC) of regions involved in food cue-reactivity...

BACKGROUND: The molecular pathology underlying posttraumatic stress disorder (PTSD) remains unclear mainly due to a lack of human PTSD postmortem brain tissue. The orexigenic neuropeptides ghrelin, neuropeptide Y, and hypocretin have been recently implicated in modulating negative affect. Drawing from the largest functional genomics study of human PTSD postmortem tissue, we investigated whether there were molecular changes of these and other appetitive molecules. Further, we explored the interaction between PTSD and body mass index (BMI) on gene expression...

PURPOSE: Validation of transcranial direct current stimulation (tDCS) to treat obesity is hampered by evidence that participants can distinguish real from the traditional-control condition. Correctly guessing the real condition precludes knowing if it is neuromodulation or expectation that suppresses food craving and eating. Therefore, this study tested the putative efficacy of tDCS to the dorsolateral prefrontal cortex (DLPFC) to reduce food craving and eating when an alternative control condition was used that would be difficult to distinguish from the real condition...

BACKGROUND AND OBJECTIVES: Family-based behavioral treatment (FBT) is the recommended treatment for children with common obesity. However, there is a large variability in short- and long-term treatment response, and mechanisms for unsuccessful treatment outcomes are not fully understood. In this study, we tested if brain response to visual food cues among children with obesity before treatment predicted weight or behavioral outcomes during a 6-month behavioral weight management program and/or long-term relative weight maintenance over a 1-year follow-up period...

Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects...

BACKGROUND/OBJECTIVES: Obesity is associated with reduced neurocognitive performance. Individuals with obesity show decreased activation in the left dorsolateral prefrontal cortex (DLPFC), a key brain region relevant to the regulation of eating behavior. Transcranial direct current stimulation (tDCS) has emerged as a potential technique to correct these abnormalities. However, there is limited information to date, particularly in clinical settings and regarding long-term effects of tDCS...

Cognitive processes contribute to the control of feeding behavior and help organism's survival when they support physiological needs. They can become maladaptive, such as when learned food cues drive feeding in the absence of hunger. Associative learning is the basis for cue-driven food seeking and consumption, and behavioral paradigms with Pavlovian cue-food conditioning are well established. Yet, the neural mechanisms underlying circuit plasticity across cue-food learning, cue memory recall, and subsequent food motivation are unknown...

Background: Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) may reduce appetite and caloric intake and may be able to play a role as an adjunct treatment for obesity. Stimulation of this brain area is also used for the treatment of depression, which shares a common pathophysiology with obesity. As a result, the effect of tDCS on mental health and its impact on the quality of life of subjects with excess weight needs to be addressed. Objective: To assess the effect of daily tDCS of the right DLPFC on mood, daytime sleepiness, anxiety and quality of life in subjects with excess weight on a hypocaloric diet...

BACKGROUND: High body mass index (BMI) is associated with neurocognitive impairments that contribute to overeating and interfere with weight loss efforts. Overweight and obesity at midlife can accelerate neurodegenerative changes and increase the risk of late-life dementia. Noninvasive neuromodulation represents a novel, affordable and scalable approach to improve neurocognitive function in this context. The purpose of this proof-of-concept study was to examine whether transcranial direct current stimulation (tDCS) aimed at enhancing prefrontal cortex activity could enhance weight loss, in combination with a hypocaloric diet, and study underlying mechanisms...

BACKGROUND: Although some studies have reported significant reductions in food cravings following the single-session of repetitive transcranial magnetic stimulation (rTMS), there is little research on the effects of multi-session of rTMS on food consumption and body weight in obese subjects. OBJECTIVE: We conducted 4-week randomized, sham-controlled, single-blind, parallel-group trial to examine the effect of rTMS on body weight in obese adults. METHODS: Forty-three obese patients (body mass index [BMI] ≥25 kg/m2 ) aged between 18 and 70 years were randomized to the sham or real treatment group (21 in the TMS group and 22 in the sham treatment group)...

In the United States over one-third of the population, including children and adolescents, are overweight or obese. Despite the prevalence of obesity, few studies have examined how food cravings and the ability to regulate them change throughout development. Here, we addressed this gap in knowledge by examining structural brain and behavioral changes associated with regulation of craving across development. In a longitudinal design, individuals ages 6-26 completed two structural scans as well as a behavioral task where they used a cognitive regulatory strategy to decrease the appetitive value of foods...

Learning accounts of addiction and obesity emphasize the persistent power of Pavlovian reward cues to trigger craving and increase relapse risk. While extinction can reduce conditioned responding, Pavlovian relapse phenomena-the return of conditioned responding following successful extinction-challenge the long-term success of extinction-based treatments. Translational laboratory models of Pavlovian relapse could therefore represent a valuable tool to investigate the mechanisms mediating relapse, although so far human research has mostly focused on return of fear phenomena...

The regulation of appetite is supported by dopamine-modulated brain circuits. Recent studies have shown that transcranial direct current stimulation (tDCS) aimed at increasing the excitability of the dorsolateral prefrontal cortex can reduce appetite, but the underlying mechanisms remain unknown, and response variability is large. The aim of this study was to determine whether individual differences in Catechol-O-methyl transferase (COMT) Val158Met polymorphism can influence tDCS effects on appetite. Thirty-eight adult women with obesity, classified as carriers or non-carriers of the Met allele, underwent a randomized, double-blind, sham-controlled tDCS intervention involving three phases: Phase I, target engagement (immediate effects of tDCS on working memory performance), Phase II, tDCS only (10 sessions, two weeks), and Phase III, tDCS + hypocaloric diet: (6 sessions, two weeks, 30% energy intake reduction, inpatient)...

In the modern obesogenic environment, limiting calorie-dense food consumption is partially dependent on the capacity of individuals to override visceral reactions to hyperpalatable and rewarding food cues. In the current review, we employ a health neuroscience framework to outline: (i) how individual variations in prefrontal cortical structure and functionality, and by extension, executive functions, may predispose an individual to the overconsumption of appetitive calorie-dense foods via differences in dietary self-regulation; (ii) how obesity may result in changes to cortical structure and functionality; and (iii) how the relationship between the structure and function of the prefrontal cortex and obesity may be best described as reciprocal in nature...

Accumulating evidence suggests that non-invasive and invasive brain stimulation may reduce food craving and calorie consumption rendering these techniques potential treatment options for obesity. Non-invasive transcranial direct current stimulation (tDCS) or repetitive transcranial magnet stimulation (rTMS) are used to modulate activity in superficially located executive control regions, such as the dorsolateral prefrontal cortex (DLPFC). Modulation of the DLPFC's activity may alter executive functioning and food reward processing in interconnected dopamine-rich regions such as the striatum or orbitofrontal cortex...

Human neuroimaging studies have consistently reported changes in cerebellar function and integrity in association with obesity. To date, however, the nature of this link has not been studied directly. Emerging evidence suggests a role for the cerebellum in higher cognitive functions through reciprocal connections with the prefrontal cortex. The purpose of this exploratory study was to examine appetite changes associated with noninvasive prefronto-cerebellar neuromodulation in obesity. Totally, 12 subjects with class I obesity (mean body mass index 32...

The "hunger" hormone ghrelin regulates food-intake and preference for high-calorie (HC) food through modulation of the mesocortico-limbic dopaminergic pathway. Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric surgery to treat morbid obesity. We tested the hypothesis that LSG-induced reductions in appetite and total ghrelin levels in blood are associated with reduced prefrontal brain reactivity to food cues. A functional magnetic resonance imaging (fMRI) cue-reactivity task with HC and low-calorie (LC) food pictures was used to investigate brain reactivity in 22 obese participants tested before and one month after bariatric surgery (BS)...

BACKGROUND/OBJECTIVE: Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric surgery to treat obesity, and involves removal of the gastric fundus where ghrelin is mainly produced. Ghrelin stimulates appetite and regulates food intake through its effect on the hypothalamus and hippocampus (HIPP). While ghrelin's role on the hypothalamus has been explored, little is known about its role on HIPP. We tested the hypothesis that LSG-induced reductions in ghrelin levels would be associated with changes in HIPP activity...