Dietary Long-Chain n-3 Polyunsaturated Fatty Acid Supplementation Alters Electrophysiological Properties in the Nucleus Accumbens and Emotional Behavior in Naïve and Chronically Stressed Mice

Natural variations of adolescent neurogenesis and anxiety predict the hierarchical status of adult inbred mice

Hierarchy provides a survival advantage to social animals in challenging circumstances. In mice, social dominance is associated with trait anxiety which is regulated by adult hippocampal neurogenesis. Here, we test whether adolescent hippocampal neurogenesis may regulate social dominance behavior in adulthood. We observe that adolescent individuals with higher trait anxiety and lower levels of hippocampal neurogenesis prior to the formation of a new group become dominants, suggesting that baseline adolescent neurogenesis predicts hierarchical status. This phenotype persists beyond social hierarchy stabilization. Experimentally reducing neurogenesis prior to the stabilization of social hierarchy in group-housed adolescent males increases the probability of mice to become dominant and increases anxiety. Finally, when innate dominance is assessed in socially isolated and anxiety-matched animals, mice with impaired neurogenesis display a dominant status toward strangers. Together, these results indicate that adolescent neurogenesis predicts and regulates hierarchical and situational dominance behavior along with anxiety-related behavior. These results provide a framework to study the mechanisms underlying social hierarchy and the dysregulation of dominance behavior in psychiatric diseases related to anxiety.

Modified neuroimmune processes and emotional behaviour in weaned and late adolescent male and female mice born via caesarean section

Elective and emergency Caesarean section (C-section) procedures are on the rise, exceeding the recommended guidelines by the World Health Organization. Higher morbidities and long-term health conditions are correlated to C-section deliveries, including neurodevelopmental disorders. During C-section delivery, newborns are not exposed to the vaginal commensal flora, which impedes the early establishment of the gut microbiota. The latter is essential for adequate neuro-immune processes to take place during infancy. In this study, we used a validated model of mice born by C-section (CSD), which mimics clinical observations of dysregulated gut microbiota. Animals were either born naturally or by CSD, before being adopted by dams who underwent delivery within the 12 preceding hours. Behavioural analyses were conducted at post-natal day (PND) 21 and 55. Our results indicate that animals born by C-section present significantly higher body weight in late (PND40-P53) but not early adolescence (PND21-P27), compared to animals born by vaginal delivery (VD). Male animals delivered by C-section presented significantly lower exploration time of the novel arm in the Y Maze test at PND55. However, at PND21, abnormal social interaction was witnessed in male and female animals born by CSD, with significantly decreased time spent interacting during the social interaction test. At both PND21 and PND55, animals from both sexes born by C-section presented significantly decreased time spent in the open arm of the Elevated Plus Maze test, compared to control animals. We then measured the expression of genes associated to neuroimmune interactions (microglia phenotype), inflammatory mediators and lipids in several brain structures of VD and CSD mice at PND21 and PND55. At weaning, animals born by CSD presented altered microglia, inflammatory and lipid metabolism signatures, with increased expression of Cd36, Csf1r and Tnfα in different brain regions of males, but not in females. At PND64, Csf1r, Tmem119 as well as C3ar1 were significantly increased in males born by C-section, but not in females. In males born by vaginal delivery, the expression of Cd36 at PND64 was correlated to anxiety at PND55, whilst a correlation between the expression of Clec7a and the number of head dippings in the elevated plus maze was also noted in males born by CSD. Altogether, our study shows altered emotional behaviour in animals delivered by CSD, which is likely explained by underlying neuro-inflammatory processes in different brain regions. Our work further supports the long-term consequences of CSD on brain health.

Microbiome and Metabolite Analysis Insight into the Potential of Shrimp Head Hydrolysate to Alleviate Depression-like Behaviour in Growth-Period Mice Exposed to Chronic Stress

Chronic stress (CS) endangers the physical and mental health of adolescents. Therefore, alleviating and preventing such negative health impacts are a top priority. This study explores the effect of feeding shrimp head hydrolysate (SHH) on gut microbiota, short-chain fatty acids (SCFAs), and neurotransmitters in growing C57BL/6 mice subjected to chronic unpredictable mild stress. Mice in the model group and three SHH groups were exposed to CS for 44 days, distilled water and SHH doses of 0.18, 0.45, 0.90 g/kg·BW were given respectively by gavage daily for 30 days from the 15th day. The results showed that SHH can significantly reverse depression-like behaviour, amino acids degradation, α diversity and β diversity, proportion of Firmicutes and Bacteroidota, abundance of genera such as Muribaculaceae, Bacteroides, Prevotellaceae_UCG-001, Parabacteroides and Alistipes, concentration of five short-chain fatty acids (SCFAs), 5-HT and glutamate induced by CS. Muribaculaceae and butyric acid may be a controlled target. This study highlights the potential and broad application of SHH as an active ingredient in food to combat chronic stress damage.

Dietary and Metabolic Approaches for Treating Autism Spectrum Disorders, Affective Disorders and Cognitive Impairment Comorbid with Epilepsy: A Review of Clinical and Preclinical Evidence

Epilepsy often occurs with other neurological disorders, such as autism, affective disorders, and cognitive impairment. Research indicates that many neurological disorders share a common pathophysiology of dysfunctional energy metabolism, neuroinflammation, oxidative stress, and gut dysbiosis. The past decade has witnessed a growing interest in the use of metabolic therapies for these disorders with or without the context of epilepsy. Over one hundred years ago, the high-fat, low-carbohydrate ketogenic diet (KD) was formulated as a treatment for epilepsy. For those who cannot tolerate the KD, other diets have been developed to provide similar seizure control, presumably through similar mechanisms. These include, but are not limited to, the medium-chain triglyceride diet, low glycemic index diet, and calorie restriction. In addition, dietary supplementation with ketone bodies, polyunsaturated fatty acids, or triheptanoin may also be beneficial. The proposed mechanisms through which these diets and supplements work to reduce neuronal hyperexcitability involve normalization of aberrant energy metabolism, dampening of inflammation, promotion of endogenous antioxidants, and reduction of gut dysbiosis. This raises the possibility that these dietary and metabolic therapies may not only exert anti-seizure effects, but also reduce comorbid disorders in people with epilepsy. Here, we explore this possibility and review the clinical and preclinical evidence where available.

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties ("brain fog"), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions. Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms. Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

A novel wrinkled-leaf sesame mutant as a potential edible leafy vegetable rich in nutrients

Sesame (Sesamum indicum L.) is an ancient and globally important oil crop in the tropic and subtropic areas. Apart from being a good source of high-quality oil, sesame also represents a new source of edible leafy vegetables. However, data regarding the nutritional composition of the sesame leaves, especially their phytonutrient composition, are scarce. Previously we have developed a sesame mutant JQA with curly, wide, and thick leaves that are potentially used as a vegetable. The objective of this work was to gauge the nutrient contents in leaves of the JQA mutant by colorimetry methods. The sesame mutant JQA and its wild-type counterpart JQB were grown in the field, and leaf samples were collected at the flowering stage. Results showed that the sesame wrinkled leaves of JQA are a rich source of crude oil (5.33-6.38%), crude protein (3.14%), amino acids (> 18.6 mg/g), crude fiber (> 0.36%), cellulose or hemicellulose (> 21.4 mg/g), sugars (> 12.5 mg/g), vitamins, and flavones (> 63.2 mg/g). The wrinkled sesame leaves were high in unsaturated acid (32.0 mg/g), calcium (18.5 mg/g), potassium (16.1 mg/g), as well as vitamin B₆ (24.5 mg/g), B₂ (14.4 mg/g), C (1.7 mg/g) and D (1.3 mg/g) compared to other common green leafy vegetables. The fresh leaves had a mean total flavone content of 65.7 mg/g and can be consumed as fresh vegetables or preserved in a dry state. Collectively, the nutritional composition of the wrinkled leaf mutant JQA was ideal and thus had high RDIs (recommended daily intakes), suggesting that the wrinkled leaves are a rich source of nutrients and therefore suitable to be consumed as a new edible green vegetable.