Neuroanatomical Correlates of Binge-Eating Behavior: At the Roots of Unstoppable Eating.

Binge-eating refers to episodes of uncontrolled eating accompanied by a perceived loss of control, which can be common in the general population. Given the profound negative consequences of persistent binge-eating such as weight and eating disorders, it is vital to determine what makes someone more vulnerable than others to engage in such a conduct. A total of 42 normal-weight individuals (21 with binge-eating episodes and 21 without binge-eating episodes) underwent a structural magnetic resonance imaging measurement and Voxel-based morphometry (VBM) was used to assess between-group differences in terms of gray matter volume (GMV), together with self-report impulsivity and binge-eating measures. The results showed binge-eating individuals as characterized by higher trait impulsivity and greater regional GMV in the left middle frontal gyrus: however, the GMV in this region appeared to be positively correlated only with measures of binge-eating but not with trait impulsivity measures. These findings provide novel insights on the neurobiological roots of BE in normal-weight individuals and highlight how this behavior can be associated with brain morphometric changes within prefrontal regions also in a non-clinical population. Overall, this study provides a further characterization of the neural correlates of binge-eating and novel insights into the treatment of its more severe pathological forms.

Metacognition in individuals recovered from anorexia nervosa: a voxel-based morphometry study.

Recent evidence shows that individuals with Anorexia Nervosa (AN) can be characterized by dysfunctional metacognition as well as reductions of gray matter volumes (GMV) in prefrontal brain regions involved in cognitive processes. However, whether these differences are reversible or stable markers has yet to be understood. Thus, we aimed at characterizing metacognition and brain morphometry in individuals recovered from AN (rec-AN). A combined psychometric-brain morphometry investigation on metacognitive functioning in rec-AN individuals was conducted. Fifteen healthy controls (HC) and fifteen rec-AN women underwent a psychometric assessment for metacognitive functioning and a high-resolution T1-weighted Magnetic Resonance Imaging measurement to assess global and regional brain volumes, using Voxel-Based Morphometry. The two groups did not differ for metacognitive functioning and GMV, while regional GMV reductions were observed in rec-AN compared to HC in the left Inferior Frontal Gyrus (IFG). While changes in metacognitive abilities may not represent a stable trait of AN, regional GMV reductions in brain regions devoted to specific cognitive functions, such as inhibitory/top-down control processes, can act as a neurobiological fingerprint for such condition. These findings can represent a promising hint for future investigations on the maintaining factors of AN.

Characterizing impulsivity and resting-state functional connectivity in normal-weight binge eaters.

OBJECTIVE: Binge eating is characterized by episodes of uncontrolled eating, within discrete periods of time. Although it is usually described in obese individuals or as a symptom of Binge Eating Disorder (BED), this behavior can also occur in the normal-weight (NW) population. An interesting premise suggests that impulsivity might contribute to the onset of binge eating and the progression toward weight gain. Drawing upon this evidence, here we explored impulsivity in NW individuals reporting binge-eating episodes through a functional connectivity approach. We hypothesized that, even in the absence of an eating disorder, NW binge eaters would be characterized by connectivity pattern changes in corticostriatal regions implicated in impulsivity, similarly to the results described in BED individuals. METHODS: A resting-state functional magnetic resonance imaging study tested 39 NW men and women, with and without binge eating (binge eaters, BE and non-BE). Brain functional connectivity was explored by means of graph theoretic centrality measures and traditional seed-based analysis; trait impulsivity was assessed with self-report questionnaires. RESULTS: The BE group was characterized by a higher degree of trait impulsivity. Brain functional connectivity measures revealed lower degree centrality within the right middle frontal gyrus, left insula/putamen and left temporoparietal regions and a lower functional connectivity between the right middle frontal gyrus and right insula in the BE group. DISCUSSION: The results support previous evidence on BED of altered functional connectivity and higher impulsivity at the roots of overeating behavior, but further extend this concept excluding any potential confounding effect exerted by the weight status.

Casein kinase iγ2 impairs fibroblasts actin stress fibers formation and delays cell cycle progression in g1.

Actin cytoskeleton remodeling is under the regulation of multiple proteins with various activities. Here, we demonstrate that the γ2 isoform of Casein Kinase I (CKIγ2) is part of a novel molecular path regulating the formation of actin stress fibers. We show that overexpression of CKIγ2 in fibroblasts alters cell morphology by impairing actin stress fibers formation. We demonstrate that this is concomitant with increased phosphorylation of the CDK inhibitor p27(Kip) and lower levels of activated RhoA, and is dependent on CKIγ2 catalytic activity. Moreover, we report that roscovitine, a potent inhibitor of cyclin-dependent kinases, including Cdk5, decreases p27(Kip) protein levels and restores actin stress fibers formation in CKIγ2 overexpressing cells, suggesting the existence of a CKIγ2-Cdk5-p27(Kip)-RhoA pathway in regulating actin remodeling. On the other hand, we also show that in a manner independent of its catalytic activity, CKIγ2 delays cell cycle progression through G1. Collectively our findings reveal that CKIγ2 is a novel player in the control of actin cytoskeleton dynamics and cell proliferation.