A crucial role for the cortical amygdala in shaping social encounters.

Aggression is an evolutionarily conserved behaviour that controls social hierarchies and protects valuable resources. In mice, aggressive behaviour can be broken down into an appetitive phase, which involves approach and investigation, and a consummatory phase, which involves biting, kicking and wrestling. Here, by performing an unsupervised weighted correlation network analysis on whole-brain FOS expression in mice, we identify a cluster of brain regions, including hypothalamic and amygdalar subregions and olfactory cortical regions, that are highly co-activated in male but not in female aggressors.

Sex-specific role of high-fat diet and stress on behavior, energy metabolism, and the ventromedial hypothalamus.

Background: Scientific evidence highlights the influence of biological sex on the relationship between stress and metabolic dysfunctions. However, there is limited understanding of how diet and stress concurrently contribute to metabolic dysregulation in both males and females. Our study aimed to investigate the combined effects of high-fat diet (HFD) induced obesity and repeated stress on fear-related behaviors, metabolic, immune, and hypothalamic outcomes in male and female mice.

Stress-activated brain-gut circuits disrupt intestinal barrier integrity and social behaviour.

Chronic stress underlies the etiology of both major depressive disorder (MDD) and irritable bowel syndrome (IBS), two highly prevalent and debilitating conditions with high rates of co-morbidity. However, it is not fully understood how the brain and gut bi-directionally communicate during stress to impact intestinal homeostasis and stress-relevant behaviours. Using the chronic social defeat stress (CSDS) model, we find that stressed mice display greater intestinal permeability and circulating levels of the endotoxin lipopolysaccharide (LPS) compared to unstressed control (CON) mice.

Frailty Worsens Antidepressant Treatment Outcomes in Late Life Depression.

Objective: To investigate the relationship between frailty and treatment response to antidepressant medications in adults with late life depression (LLD).

Methods: Data were evaluated from 100 individuals over age 60 years (34 men, 66 women) with a depressive diagnosis, who were assessed for frailty at baseline (characteristics include gait speed, grip strength, activity levels, fatigue, and weight loss) and enrolled in an 8-week trial of antidepressant medication followed by 10 months of open-treatment.

Results: Frail individuals (n = 49 with ≥3 deficits in frailty characteristics) did not differ at baseline from the non/intermediate frail (n = 51 with 0-2 deficits) on demographic, medical comorbidity, cognitive, or depression variables.