Leptin moderates the relationship between sleep quality and memory function: A population-based study.

Sleep is crucial for memory, as it promotes its encoding, consolidation, storage, and retrieval. Sleep periods following learning enhance memory consolidation. Leptin, a hormone that regulates appetite and energy balance, also influences memory and neuroplasticity. It plays a neurotrophic role in the hippocampus, enhancing synaptic function and promoting memory processes. Given these associations between sleep, memory, and leptin, this study aimed to evaluate the interplay between sleep quality, memory complaints and leptin levels. Using data from the São Paulo Epidemiologic Sleep Study (EPISONO) 2007 edition, we analyzed data from 881 participants who underwent evaluations for subjective sleep quality (Pittsburgh Sleep Quality Index), memory function (Prospective and Retrospective Memory Questionnaire), body mass index and plasmatic leptin levels. After confirming that subjects with poor sleep quality had more memory complaints in our cohort, we observed that leptin levels were increased in individuals with more memory complaints, but there was no association between leptin levels and sleep quality. Mediation analysis reinforced the direct effect of sleep quality on memory function, but leptin had no indirect effect as mediator over the sleep-memory association. Moderation analysis revealed that leptin acted as a moderator in the relationship between sleep quality and memory, with increased leptin levels enhancing the effect of sleep quality over memory function. These findings underscore the intricate interplay between sleep, memory, and metabolic factors like leptin, shedding light on potential mechanisms through which sleep influences memory and cognitive functions. Further research is needed to elucidate the exact mechanisms underlying these relationships and their implications for overall health and well-being.

Exploring the molecular pathways linking sleep phenotypes and POGZ-associated neurodevelopmental disorder.

Pogo transposable element-derived protein with ZNF domain (POGZ) gene encodes a chromatin regulator and rare variants on this gene have been associated with a broad spectrum of neurodevelopmental disorders, such as White-Sutton syndrome. Patient clinical manifestations frequently include developmental delay, autism spectrum disorder and obesity. Sleep disturbances are also commonly observed in these patients, yet the biological pathways which link sleep traits to the POGZ-associated syndrome remain unclear. We screened for sleep implications among individuals with causative POGZ variants previously described. Sleep disturbances were observed in 52% of patients, and being obese was not observed as a risk factor for sleep problems. Next, we identified genes associated with sleep-associated traits among the POGZ regulatory targets, aiming to uncover the molecular pathways that, when disrupted by POGZ loss of function, contribute to the aetiology of sleep phenotypes in these patients. The intersect between POGZ targets and sleep-related genes was used in a pathway enrichment analysis. Relevant pathways among these overlapping genes are involved in the regulation of circadian rhythm, tau protein binding, ATPase activator activity. This study may represent the beginning for novel functional investigations on shared molecular mechanisms between sleep disturbances and rare developmental syndromes related to POGZ and its regulatory targets.

The relationship between neurodevelopmental transcriptional programs and insomnia: From Rubinstein-Taybi syndrome into energy metabolism.

Neurodevelopmental disorders (NDD) are characterized by cognitive, emotional, and/or motor skills impairment since childhood, and sleep disturbances are a common comorbidity. Rubinstein-Taybi syndrome (RSTS), a rare genetic syndrome associated with NDD, is caused by CREBBP haploinsufficiency. This gene encodes an acetyltransferase with crucial role on the establishment of transcriptional programs during neurodevelopment. Although insomnia has been reported in RSTS patients, the convergent mechanisms between this sleep disturbance and CREBBP loss-of-function are not fully understood. We tested weather the genetic architecture underlying CREBBP regulatory targets and insomnia-associated genes is significantly shared. We then identified the biological pathways enriched among these shared genes. The intersection between CREBBP regulatory targets and genes associated with insomnia included 7 overlapping genes, indicating significantly more overlap than expected by chance. An over-representation analysis on these intersect genes identified pathways related to mitochondrial activity. This finding indicates that the transcriptional programs established by CREBBP might impact insomnia-related biological pathways through the modulation of energy metabolism. The overlapping gene set and biological pathways highlighted by this study may serve as a primer for new functional investigations of shared molecular mechanisms between insomnia and CREBBP regulatory targets.

Endocrine and Epigenetic Regulation as Common Pathways Underlying the Genetic Basis of Sleep Traits and Longevity.

The amount of sleep needed over one's lifespan is age dependent and not sleeping enough or sleeping in excess is associated with increased morbidity and mortality. Yet, the convergent molecular mechanisms that link longevity and sleep are largely unknown. We performed a gene enrichment study that (1) identified genes associated with both longevity and sleep traits and (2) determined molecular pathways enriched among these shared genes. We manually curated two sets of genes, one associated with longevity and aging and the other with sleep traits (e.g., insomnia, narcolepsy, sleep duration, chronotype, among others), with both gene lists heavily driven by hits from recent large-scale Genome-Wide Association Studies. There were 47 overlapping genes between the gene list associated with sleep traits (1064 genes total) and the genes associated with longevity (367 genes total), indicating significantly more overlap than expected by chance. An overrepresentation analysis identified enriched pathways that suggest endocrine and epigenetic regulation as potential shared mechanisms between sleep traits and longevity. Concordantly, functional network analysis retrieved two clusters, being one associated with proteins of nuclear functions and the other, with extracellular proteins. This overlapping gene set, and the highlighted biological pathways may serve as preliminary findings for new functional investigations of sleep and longevity shared genetic mechanisms.

Simple and efficient protocol to isolate and culture brain microvascular endothelial cells from newborn mice.

The neurovascular unit (NVU) is a multicellular structure comprising of neurons, glial cells, and non-neural cells, and it is supported by a specialized extracellular matrix, the basal lamina. Astrocytes, brain microvascular endothelial cells (BMECs), pericytes, and smooth muscle cells constitute the blood-brain barrier (BBB). BMECs have a mesodermal origin and invade the nervous system early in neural tube development, forming the BBB anatomical core. BMECs are connected by adherent junction complexes composed of integral membrane and cytoplasmic proteins. In vivo and in vitro studies have shown that, given the proximity and relationship with neural cells, BMECs acquire a unique gene expression profile, proteome, and specific mechanical and physical properties compared to endothelial cells from the general vasculature. BMECs are fundamental in maintaining brain homeostasis by regulating transcellular and paracellular transport of fluids, molecules, and cells. Therefore, it is essential to gain in-depth knowledge of the dynamic cellular structure of the cells in the NVU and their interactions with health and disease. Here we describe a significantly improved and simplified protocol using C57BL/6 newborn mice at postnatal day 1 (PND1) to isolate, purify, and culture BMECs monolayers in two different substrates (glass coverslips and transwell culture inserts). In vitro characterization and validation of the BMEC primary culture monolayers seeded on glass or insert included light microscopy, immunolabeling, and gene expression profile. Transendothelial electrical resistance (TEER) measurement and diffusion test were used as functional assays for adherent junction complexes and integrity and permeability of BMECs monolayers. The protocol presented here for the isolation and culture of BMECs is more straightforward than previously published protocols and yields a high number of purified cells. Finally, we tested BMECs function using the oxygen-glucose deprivation (OGD) model of hypoxia. This protocol may be suitable as a bioscaffold for secondary cell seeding allowing the study and better understanding of the NVU.

COVID-19 and epilepsy: How are people with epilepsy in Brazil?

PURPOSE: During COVID-19 pandemic the global population is facing an important psychosocial distress. The aim of this study was to evaluate how people with epilepsy (PWE) in Brazil is dealing with the pandemic, in relation to seizure frequency, access to antiseizure medicines (ASM), medical follow-up, and well-being. METHODS: An online questionnaire survey among PWE (group 1) and caregivers (group 2) was applied in the social networks of the Brazilian Association of Epilepsy, the official Brazilian chapter of the International Bureau for Epilepsy. The questionnaire was composed of 46 generic questions in four areas, namely, demographics and baseline clinical data as well as epilepsy and quality-of-life impact by COVID-19 pandemic based on the domains of the abbreviated World Health Organization Quality of Life (WHOQOL-BREF) instrument. RESULTS: The questionnaire was answered by 464 participants including 380 (81.9%) PWE (78.7% female; age 34.3 yrs.; ±9.76) and 84 (18.1%) caregivers (patients' age 14.1 yrs.; ±10.30). During the COVID-19 pandemic, 36.8% of PWE and 36.4% of caregivers reported difficulties in accessing the epilepsy healthcare provider, and visits occurred normally only in 29.7% of PWE and in 34.5% of the caregivers group. Telehealth was not provided for 66.6% of group 1 and for 58.5% of group 2. Lack of availability of ASM was reported by 21.9% of PWE and 28.0% of caregivers in public dispensing units and by 19.2% and 17.8%, respectively, in private pharmacies. Increase in seizures during pandemic was mentioned by 26.3% and 27.9% of groups 1 and 2, respectively. Patients who had increase in seizure frequency had more frequently reported problems with treatment and in quality-of-life concepts. Fear of having a more severe COVID-19 presentation because of epilepsy was reported by 74.5% of PWE and by 89.8% of caregivers. Dissatisfaction with current health status was reported by 36.7% and 38.1% in groups 1 and 2, respectively, and that the support from others has decreased (56.1% and 66.1%, in groups 1 and 2) during the pandemic. The factors with higher Odds Ratio of increase in seizure frequency during pandemic were age >41 yrs., treatment in public healthcare system, drug-resistant epilepsy, adversities in getting ASM in public dispensing units, difficulties with prescription renewals, current financial problems and belief that epilepsy or ASM are risk factors for contracting COVID-19. CONCLUSION: During COVID-19 pandemic in Brazil, PWE and caregivers reported increase in seizures in one-fourth of the patients and several difficulties, namely problems in accessing the healthcare system including ASM dispensation, telehealth, and fear of having a more severe COVID-19 because of epilepsy. There were also physical, psychological, and social concerns which affected quality-of-life-related aspects in this population. These facts may increase treatment gap in epilepsy in Brazil as well in other developing countries.

Leptin enhances adult neurogenesis and reduces pathological features in a transgenic mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common dementia worldwide and is characterized by the presence of senile plaques by amyloid-beta (Aß) and neurofibrillary tangles of hyperphosphorylated Tau protein. These changes lead to progressive neuronal degeneration and dysfunction, resulting in severe brain atrophy and cognitive deficits. With the discovery that neurogenesis persists in the adult mammalian brain, including brain regions affected by AD, studies of the use of neural stem cells (NSCs) for the treatment of neurodegenerative diseases to repair or prevent neuronal cell loss have increased. Here we demonstrate that leptin administration increases the neurogenic process in the dentate gyrus of the hippocampus as well as in the subventricular zone of lateral ventricles of adult and aged mice. Chronic treatment with leptin increased NSCs proliferation with significant effects on proliferation and differentiation of newborn cells. The expression of the long form of the leptin receptor, LepRb, was detected in the neurogenic niches by reverse qPCR and immunohistochemistry. Moreover, leptin modulated astrogliosis, microglial cell number and the formation of senile plaques. Additionally, leptin led to attenuation of Aß-induced neurodegeneration and superoxide anion production as revealed by Fluoro-Jade B and dihydroethidium staining. Our study contributes to the understanding of the effects of leptin in the brain that may lead to the development of new therapies to treat Alzheimer's disease.

A novel decellularization method to produce brain scaffolds.

Scaffolds composed of extracellular matrix (ECM) can assist tissue remodeling and repair following injury. The ECM is a complex biomaterial composed of proteins, glycoproteins, proteoglycans, and glycosaminoglycans, secreted by cells. The ECM contains fundamental biological cues that modulate cell behavior and serves as a structural scaffold for cell adhesion and growth. For clinical applications, where immune rejection is a constraint, ECM can be processed using decellularization methods intended to remove cells and donor antigens from tissue or organs, while preserving native biological cues essential for cell growth and differentiation. Recent studies show bioengineered organs composed by a combination of a diversity of materials and stem cells as a possibility of new therapeutic strategies to treat diseases that affect different tissues and organs, including the central nervous system (CNS). Nevertheless, the methodologies currently described for brain decellularization involve the use of several chemical reagents with many steps that ultimately limit the process of organ or tissue recellularization. Here, we describe for the first time a fast and straightforward method for complete decellularization of mice brain by the combination of rapid freezing and thawing following the use of only one detergent (Sodium dodecyl sulfate (SDS)). Our data show that using the protocol we describe here, the brain was entirely decellularized, while still maintaining ECM components that are essential for cell survival on the scaffold. Our results also show the cell-loading of the decellularized brain matrix with Neuro2a cells, which were identified by immunohistochemistry in their undifferentiated form. We conclude that this novel and simple method for brain decellularization can be used as a scaffold for cell-loading.

Lipopolysaccharide-Induced Systemic Inflammation in the Neonatal Period Increases Microglial Density and Oxidative Stress in the Cerebellum of Adult Rats.

Inflammatory processes occurring in the perinatal period may affect different brain regions, resulting in neurologic sequelae. Injection of lipopolysaccharide (LPS) at different neurodevelopmental stages produces long-term consequences in several brain structures, but there is scarce evidence regarding alterations in the cerebellum. The aim of this study was to evaluate the long-term consequences on the cerebellum of a systemic inflammatory process induced by neonatal LPS injection. For this, neonatal rats were randomly assigned to three different groups: naïve, sham, and LPS. Saline (sham group) or LPS solution (1 mg/kg) was intraperitoneally injected on alternate postnatal days (PN) PN1, PN3, PN5, and PN7. Spontaneous activity was evaluated with the open field test in adulthood. The cerebellum was evaluated for different parameters: microglial and Purkinje cell densities, oxidative stress levels, and tumor necrosis factor alpha (TNF-α) mRNA expression. Our results show that administration of LPS did not result in altered spontaneous activity in adult animals. Our data also indicate increased oxidative stress in the cerebellum, as evidenced by an increase in superoxide fluorescence by dihydroethidium (DHE) indicator. Stereological analyses indicated increased microglial density in the cerebellum that was not accompanied by Purkinje cell loss or altered TNF-α expression in adult animals. Interestingly, Purkinje cells ectopically positioned in the granular and molecular layers of the cerebellum were observed in animals of the LPS group. Our data suggest that neonatal LPS exposure causes persistent cellular and molecular changes to the cerebellum, indicating the susceptibility of this region to systemic inflammatory insults in infancy. Further investigation of the consequences of these changes and the development of strategies to avoid those should be subject of future studies.

LPS-Induced Systemic Neonatal Inflammation: Blockage of P2X7R by BBG Decreases Mortality on Rat Pups and Oxidative Stress in Hippocampus of Adult Rats.

Neonatal lipopolysaccharide (LPS) exposure-induced brain inflammation has been associated to neuronal injury and facilitates the development of models of neurological disorders in adult rats. The P2X7 receptor (P2X7R) plays a fundamental role in the onset and maintenance of the inflammatory cascade. Brilliant blue G (BBG), a P2X7R antagonist, has been shown to effectively promote neuroinflammatory protection. Here, we have investigated the long-term effects of the neonatal systemic inflammation on hippocampal oxidative stress, anxiety behavior and pain sensitivity in adulthood. We hypothesized that P2X7R blockade is able to modulate the effects of inflammation on these variables. Male and female rat pups received LPS and/or BBG solution intraperitoneally on the 1st, 3rd, 5th and 7th postnatal days. The survival rate and body weight were evaluated during the experimental procedures. The animals were submitted to behavioral tests for anxiety (elevated plus maze, EPM) and nociception (hot-plate and tail-flick) and the oxidative stress was measured by superoxide production in the dentate gyrus of the hippocampus using dihydroethidium (DHE) probe. BBG increased the survival rate in LPS-treated rats. No significant differences were found regarding anxiety behavior and pain sensitivity between the experimental groups. Systemic neonatal inflammation leads to a higher production of superoxide anion in the dentate gyrus of the hippocampus in adulthood and BBG inhibited that effect. Our data suggest that blocking the activation of the P2X7R during neonatal systemic inflammation may have a potential neuroprotective effect in adulthood.

Neurophysiological, cognitive-behavioral and neurochemical effects in practitioners of transcendental meditation - A literature review.

The term meditation can be used in many different ways, according to the technique to which it refers. Transcendental Meditation (MT) is one of these techniques. TM could serve as a model for research on spiritual meditation, unlike the meditation techniques based on secular knowledge. The purpose of the present study is to conduct a bibliographic review to organize scientific evidence on the effects of TM on neurophysiology, neurochemistry, and cognitive and behavioral aspects of its practitioners. To conduct this critical narrative review of the literature, we searched for scientific papers on the PubMed database of the National Center for Biotechnology Information. The keywords used in the search were Transcendental Meditation, Neuroscience of meditation e Meditation and behavior. We selected 21 papers that analyzed different aspects that could be altered through meditation practice. We concluded that TM has positive and significant documentable neurochemical, neurophysiological, and cognitive-behavioral effects. Among the main effects are the reduction of anxiety and stress (due to the reduction of cortisol and norepinephrine levels), increase of the feeling of pleasure and well-being (due to the increase of the synthesis and release of dopamine and serotonin), and influence on memory recall and possible consolidation. Further studies are needed using creative and innovative methodological designs that analyze different neural circuitry and verify the clinical impact on practitioners.

Neurophysiological, cognitive-behavioral and neurochemical effects in practitioners of transcendental meditation - A literature review

SUMMARY The term meditation can be used in many different ways, according to the technique to which it refers. Transcendental Meditation (MT) is one of these techniques. TM could serve as a model for research on spiritual meditation, unlike the meditation techniques based on secular knowledge. The purpose of the present study is to conduct a bibliographic review to organize scientific evidence on the effects of TM on neurophysiology, neurochemistry, and cognitive and behavioral aspects of its practitioners. To conduct this critical narrative review of the literature, we searched for scientific papers on the PubMed database of the National Center for Biotechnology Information. The keywords used in the search were Transcendental Meditation, Neuroscience of meditation e Meditation and behavior. We selected 21 papers that analyzed different aspects that could be altered through meditation practice. We concluded that TM has positive and significant documentable neurochemical, neurophysiological, and cognitive-behavioral effects. Among the main effects are the reduction of anxiety and stress (due to the reduction of cortisol and norepinephrine levels), increase of the feeling of pleasure and well-being (due to the increase of the synthesis and release of dopamine and serotonin), and influence on memory recall and possible consolidation. Further studies are needed using creative and innovative methodological designs that analyze different neural circuitry and verify the clinical impact on practitioners.

RESUMO O termo meditação pode ser utilizado de diversas formas, de acordo com a técnica a que se refere. A meditação transcendental (MT) é uma dessas técnicas meditativas. A MT pode ser um modelo para pesquisas de meditação espiritual, diferentemente de técnicas de meditação baseadas em uma compreensão secular. O presente estudo objetiva realizar uma revisão bibliográfica para organizar as evidências científicas sobre os efeitos da MT sobre a neurofisiologia, neuroquímica e aspectos cognitivos e comportamentais dos seus praticantes. Para a realização desta revisão narrativa crítica da literatura, foi realizado um levantamento dos artigos científicos presentes na base de dados PubMed do National Center for Biotechnology Information. As palavras-chave utilizadas na busca foram Transcendental Meditation, Neuroscience of meditation e Meditation and behavior. Foram selecionados 21 artigos que analisavam diferentes aspectos que poderiam ser alterados pela prática meditativa. Conclui-se que a MT produz efeitos neuroquímicos, neurofisiológicos e cognitivo-comportamentais documentáveis em seus praticantes, de caráter positivo e significativo. Entre os principais efeitos estão a diminuição da ansiedade e do estresse (via diminuição nos níveis de cortisol e noradrenalina), aumento na sensação de prazer e bem-estar (em decorrência ao aumento na síntese e liberação de dopamina e serotonina) e influência na evocação e possível consolidação da memória. São necessários mais estudos utilizando desenhos metodológicos inovadores e criativos, analisando diferentes circuitos neurais e verificando o impacto clínico sobre os praticantes.

Are We Ready for a True Biopsychosocial-Spiritual Model? The Many Meanings of "Spiritual".

The biopsychosocial model is a modern humanistic and holistic view of the human being in health sciences. Currently, many researchers think the biopsychosocial model should be expanded to include the spiritual dimension as well. However, "spiritual" is an open and fluid concept, and it can refer to many different things. This paper intends to explore the spiritual dimension in all its meanings: the spirituality-and-health relationship; spiritual-religious coping; the spirituality of the physician affecting his/her practice; spiritual support for inpatients; spiritual complementary therapies; and spiritual anomalous phenomena. In order to ascertain whether physicians would be willing to embrace them all in practice, each phrase from the Physician's Pledge on the Declaration of Geneva (World Medical Association) was "translated" in this paper to its spiritual equivalent. Medical practice involves a continuous process of revisions of applied concepts, but a true paradigm shift will occur only when the human spiritual dimension is fully understood and incorporated into health care. Then, one will be able to cut stereotypes and use the term "biopsychosocial-spiritual model" correctly. A sincere and profound application of this new view of the human being would bring remarkable transformations to the concepts of health, disease, treatments, and cure.