Repetitive Transcranial Magnetic Stimulation: A Potential Treatment for Obesity in Patients with Schizophrenia.

Obesity is highly prevalent in patients with schizophrenia and, in association with metabolic syndrome, contributes to premature deaths of patients due to cardiovascular disease complications. Moreover, pharmacologic, and behavioral interventions have not stemmed the tide of obesity in schizophrenia. Therefore, novel effective interventions are urgently needed. Repetitive transcranial magnetic stimulation (rTMS) has shown efficacy for inducing weight loss in obese non-psychiatric samples but this promising intervention has not been evaluated as a weight loss intervention in patients with schizophrenia. In this narrative review, we describe three brain mechanisms (hypothalamic inflammation, dysregulated mesocorticolimbic reward system, and impaired prefrontal cortex function) implicated in the pathogenesis and pathophysiology of obesity and emphasize how the three mechanisms have also been implicated in the neurobiology of schizophrenia. We then argue that, based on the three overlapping brain mechanisms in obesity and schizophrenia, rTMS would be effective as a weight loss intervention in patients with schizophrenia and comorbid obesity. We end this review by describing how deep TMS, relative to conventional TMS, could potentially result in larger effect size for weight loss. While this review is mainly conceptual and based on an extrapolation of findings from non-schizophrenia samples, our aim is to stimulate research in the use of rTMS for weight loss in patients with schizophrenia.

Measuring heightened attention to alcohol in a naturalistic setting: A validation study.

Attentional bias to alcohol-related stimuli is believed to be an important contributor to the development and maintenance of drug abuse. There is a considerable body of research examining attentional bias, much of which has typically utilized image-display tasks as a means to assess the phenomenon. Little, however, is known about the nature of this bias in an individual's natural environment. The current study sought to implement a novel approach to assessing attentional bias in vivo. Participants wore portable eye-tracking glasses that recorded video from their point of view and measured fixation time to objects they observed. They entered a room that was designed to represent a recreational setting in which both alcohol- and nonalcoholic-neutral beverages were placed along with other stimuli. In two different testing sessions, participants were free to visually explore the room. Participants showed similar fixation times to alcohol and neutral beverages during Session 1. Attentional bias to alcoholic beverages was observed in Session 2 because fixation time decreased to neutral but not to alcoholic beverages. The magnitude of attentional bias was positively associated with drinking habits, with heavier drinkers demonstrating a higher degree of bias to alcohol. These findings provide an ecological model of how attentional bias can develop as the net result of attention being sustained to alcoholic stimuli while diminishing to other stimuli over time. (PsycINFO Database Record

Multisensory Stop Signals Can Reduce the Disinhibiting Effects of Alcohol in Adults.

BACKGROUND: Alcohol impairs drinkers' abilities to inhibit inappropriate responses. Certain stimulus conditions have been shown to facilitate behavioral control. Under conditions where individuals are presented with multiple inhibitory signals, the speed and consistency with which they are able to inhibit a response is improved. Recent research has shown that multisensory signals might protect against the disruptive effects of alcohol on mechanisms of behavioral control. This study examined whether multisensory stop signals can be used to improve inhibitory control, possibly by speeding attentional shifts toward inhibitory "stop" signals in the environment. METHODS: Twenty adult social drinkers performed a modified cued go/no-go task that measured the ability to inhibit prepotent responses following 0.64 g/kg alcohol and placebo. Response targets were presented as unimodal (visual) and as multisensory (visual + aural) stimuli. RESULTS: Results showed that during unimodal response target trials, participants made more inhibitory failures under 0.64 g/kg alcohol compared to placebo. During multisensory trials, however, there was no significant effect of alcohol on inhibitory control. CONCLUSIONS: These findings identify multisensory inhibitory signals as a potentially important environmental factor that can reduce the degree to which alcohol disinhibits behavior possibly by intersensory co-activation between the visual and auditory pathways.

Alcohol-related visual cues impede the ability to process auditory information: Seeing but not hearing.

Studies of visual attention find that drinkers spend more time attending to images of alcohol-related stimuli compared to neutral images. It is believed that this attentional bias contributes to the maintenance of alcohol use. However, no research has examined the possibility that this bias of visual attention might actually impede the functioning of other modalities, such as the processing of accompanying auditory stimuli. This study aimed to determine if alcohol-related images engender greater sensory dominance than neutral images, such that processing accompanying information from another modality (audition) would be impeded. Drinkers who had an attentional bias to alcohol-related images performed a multisensory perception task that measured how alcohol-related versus neutral visual images affected their ability to detect and respond to simultaneously presented auditory signals. In accord with the hypothesis, compared with neutral images, the presentation of alcohol-related images impaired the ability to detect and respond to auditory signals. Increased dominance of the visual modality was demonstrated by more bimodal targets being misclassified as visual-only targets in the alcohol target condition compared with that of the neutral. Findings suggest that increased processing of alcohol-related stimuli may impede an individual's ability to encode and interpret information obtained from other sensory modalities.

Female choice reveals terminal investment in male mealworm beetles, Tenebrio molitor, after a repeated activation of the immune system.

Increasing evidence suggests that secondary sexual traits reflect immunocompetence of males in many animal species. This study experimentally investigated whether a parasite-like immunological challenge via a nylon implant affects sexual attractiveness of males in Tenebrio molitor L. (Coleoptera: Tenebrionidae) Although a single immunological challenge significantly reduced sexual attractiveness and locomotor activity of males, it had no adverse effect on their survival. A second immune challenge of the same males increased their attractiveness. However, it was found that the repeated challenge significantly reduced locomotor activity of males and caused higher mortality. This result indicates terminal investment on sexual signaling, which is supposedly based on a trade-off between pheromone production and energy expenditures needed for such activities as recovery of immune system and locomotor activity. When the third implantation was carried out in the same group of males, melanization of nylon implants was found to be lower in more attractive than in less attractive males. This suggests that males that became sexually attractive after the second immune challenge did not invest in recovery of their immune system.

Iron overload in Hepc1(-/-) mice is not impairing glucose homeostasis.

Diabetes Mellitus is found with increasing frequency in iron overload patients with hemochromatosis. In these conditions, the pancreas shows predominant iron overload in acini but also islet beta-cells. We assess glucose homeostasis status in iron-overloaded hepcidin-deficient mice. These mice presented with heavy pancreatic iron deposits but only in the acini. The beta-cell function was found unaffected with a normal production and secretion of insulin. The mutant mice were not diabetic, responded as the control group to glucose and insulin challenges, with no alteration of insulin signalling in the muscle and the liver. These results indicate that, beta-cells iron deposits-induced decreased insulin secretory capacity might be of primary importance to trigger diabetes in hemochromatosic patients.