The Vessels Shaping Mental Health or Illness

Foxp1 suppresses cortical angiogenesis and attenuates HIF-1alpha signaling to promote neural progenitor cell maintenance

Neural progenitor cells within the cerebral cortex undergo a characteristic switch between symmetric self-renewing cell divisions early in development and asymmetric neurogenic divisions later. Yet, the mechanisms controlling this transition remain unclear. Previous work has shown that early but not late neural progenitor cells (NPCs) endogenously express the autism-linked transcription factor Foxp1, and both loss and gain of Foxp1 function can alter NPC activity and fate choices. Here, we show that premature loss of Foxp1 upregulates transcriptional programs regulating angiogenesis, glycolysis, and cellular responses to hypoxia. These changes coincide with a premature destabilization of HIF-1α, an elevation in HIF-1α target genes, including Vegfa in NPCs, and precocious vascular network development. In vitro experiments demonstrate that stabilization of HIF-1α in Foxp1-deficient NPCs rescues the premature differentiation phenotype and restores NPC maintenance. Our data indicate that the endogenous decline in Foxp1 expression activates the HIF-1α transcriptional program leading to changes in the tissue environment adjacent to NPCs, which, in turn, might alter their self-renewal and neurogenic capacities.

Oxygen and the Spark of Human Brain Evolution: Complex Interactions of Metabolism and Cortical Expansion across Development and Evolution

Scientific theories on the functioning and dysfunction of the human brain require an understanding of its development-before and after birth and through maturation to adulthood-and its evolution. Here we bring together several accounts of human brain evolution by focusing on the central role of oxygen and brain metabolism. We argue that evolutionary expansion of human transmodal association cortices exceeded the capacity of oxygen delivery by the vascular system, which led these brain tissues to rely on nonoxidative glycolysis for additional energy supply. We draw a link between the resulting lower oxygen tension and its effect on cytoarchitecture, which we posit as a key driver of genetic developmental programs for the human brain-favoring lower intracortical myelination and the presence of biosynthetic materials for synapse turnover. Across biological and temporal scales, this protracted capacity for neural plasticity sets the conditions for cognitive flexibility and ongoing learning, supporting complex group dynamics and intergenerational learning that in turn enabled improved nutrition to fuel the metabolic costs of further cortical expansion. Our proposed model delineates explicit mechanistic links among metabolism, molecular and cellular brain heterogeneity, and behavior, which may lead toward a clearer understanding of brain development and its disorders.

The effect of exercise on blood concentrations of angiogenesis markers in older adults: A systematic review and meta-analysis

Impaired angiogenesis is associated with cognitive decline in older adults. While exercise has been broadly associated with increased angiogenesis, the relevant mechanisms in older adults are not clear. Here, we present a systematic review and meta-analysis on the relationship between exercise and specific blood angiogenesis markers in older adults to better understand the relevant mechanisms. MEDLINE, Embase, and Cochrane CENTRAL were searched for original reports of angiogenesis markers' concentrations in blood before and after exercise in older adults (≥50 years). Heterogeneity was investigated using sub-group analyses and meta-regressions. Of the 44 articles included in the review, 38 were included in the meta-analyses for five markers: vascular endothelial growth factor (VEGF), e-selectin (CD62E), endostatin, fibroblast growth factor 2, and matrix metallopeptidase-9. VEGF levels were higher (SMD[95%CI]= 0.18[0.03, 0.34], and CD62E levels were lower (SMD[95%CI]= -0.72[-1.42, -0.03], p = 0.04) after exercise. No other markers were altered. Although more studies are needed, changes in angiogenesis markers may help explain the beneficial effects of exercise on angiogenesis in older adults.

EphB1 controls long-range cortical axon guidance through a cell non-autonomous role in GABAergic cells

EphB1 is required for proper guidance of cortical axon projections during brain development, but how EphB1 regulates this process remains unclear. We show here that EphB1 conditional knockout (cKO) in GABAergic cells (Vgat-Cre), but not in cortical excitatory neurons (Emx1-Cre), reproduced the cortical axon guidance defects observed in global EphB1 KO mice. Interestingly, in EphB1 cKOVgat mice, the misguided axon bundles contained co-mingled striatal GABAergic and somatosensory cortical glutamatergic axons. In wild-type mice, somatosensory axons also co-fasciculated with striatal axons, notably in the globus pallidus, suggesting that a subset of glutamatergic cortical axons normally follows long-range GABAergic axons to reach their targets. Surprisingly, the ectopic axons in EphB1 KO mice were juxtaposed to major blood vessels. However, conditional loss of EphB1 in endothelial cells (Tie2-Cre) did not produce the axon guidance defects, suggesting that EphB1 in GABAergic neurons normally promotes avoidance of these ectopic axons from the developing brain vasculature. Together, our data reveal a new role for EphB1 in GABAergic neurons to influence proper cortical glutamatergic axon guidance during brain development.

Glycosylation: A new signaling paradigm for the neurovascular diseases

A wide range of life-threatening conditions with complicated pathogenesis involves neurovascular disorders encompassing Neurovascular unit (NVU) damage. The pathophysiology of NVU is characterized by several features including tissue hypoxia, stimulation of inflammatory and angiogenic processes, and the initiation of intricate molecular interactions, collectively leading to an elevation in blood-brain barrier permeability, atherosclerosis and ultimately, neurovascular diseases. The presence of compelling data about the significant involvement of the glycosylation in the development of diseases has sparked a discussion on whether the abnormal glycosylation may serve as a causal factor for neurovascular disorders, rather than being just recruited as a secondary player in regulating the critical events during the development processes like embryo growth and angiogenesis. An essential tool for both developing new anti-ischemic therapies and understanding the processes of ischemic brain damage is undertaking pre-clinical studies of neurovascular disorders. Together with the post-translational modification of proteins, the modulation of glycosylation and its enzymes implicates itself in several abnormal activities which are known to accelerate neuronal vasculopathy. Despite the failure of the majority of glycosylation-based preclinical and clinical studies over the past years, there is a significant probability to provide neuroprotection utilizing modern and advanced approaches to target abnormal glycosylation activity at embryonic stages as well. This article focuses on a variety of experimental evidence to postulate the interconnection between glycosylation and vascular disorders along with possible treatment options.

A systematic review and meta-analysis on the ocular characteristics in children and adolescents with neurodevelopmental disorders

To conduct a systematic review and meta-analysis of the association between children and adolescents with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) and ocular characteristics. Systematic review with meta-analysis. Six databases (PubMed, Scopus, APA PsycInfo, Embase, EBSCOhost, and Cochrane library) were selected for a systematic literature search from database inception to July 2022. The observational studies assessing and reporting at least one outcome regarding ocular characteristics in children and adolescents with ADHD or ASD aged 6-17 were included. Studies in languages other than English, studies of adult or elderly human populations, and animal studies were excluded. The results were analyzed following the PRISMA guideline 2020. The findings of 15 studies, including 433 participants with ADHD, 253 participants with ASD, and 514 participants with typical development (TD), revealed that there were no significant differences in retinal nerve fiber layer, ganglion cell complex, and macular thickness between the ADHD group and the TD group. In subgroup analysis, significant differences in inferior ganglion cell (MD = - 3.19; 95% CI = [- 6.06, - 0.31], p = 0.03) and nasal macular thickness (MD = 5.88; 95% CI = [- 0.01, 11.76], p = 0.05) were detected between the ADHD group and the TD group. A significant difference in pupillary light reflex (PLR) was also observed between the ASD group and the TD group (MD = 29.7; 95% CI = [18.79, 40.63], p < 0.001). Existing evidence suggests a possible association between children and adolescents with ADHD or ASD and ocular characteristics. Given the limited number of studies, further research on a larger cohort is necessary to claim a possible diagnosis of ADHD or ASD through ocular characteristics.

Astroglial Hmgb1 regulates postnatal astrocyte morphogenesis and cerebrovascular maturation

Astrocytes are intimately linked with brain blood vessels, an essential relationship for neuronal function. However, astroglial factors driving these physical and functional associations during postnatal brain development have yet to be identified. By characterizing structural and transcriptional changes in mouse cortical astrocytes during the first two postnatal weeks, we find that high-mobility group box 1 (Hmgb1), normally upregulated with injury and involved in adult cerebrovascular repair, is highly expressed in astrocytes at birth and then decreases rapidly. Astrocyte-selective ablation of Hmgb1 at birth affects astrocyte morphology and endfoot placement, alters distribution of endfoot proteins connexin43 and aquaporin-4, induces transcriptional changes in astrocytes related to cytoskeleton remodeling, and profoundly disrupts endothelial ultrastructure. While lack of astroglial Hmgb1 does not affect the blood-brain barrier or angiogenesis postnatally, it impairs neurovascular coupling and behavior in adult mice. These findings identify astroglial Hmgb1 as an important player in postnatal gliovascular maturation.

Choroidal structural analysis in ultra-high risk and first-episode psychosis

Both structural and functional alterations in the retina and the choroid of the eye, as parts of the central nervous system, have been shown in psychotic disorders, especially in schizophrenia. In addition, genetic and imaging studies indicate vascular and angiogenesis anomalies in the psychosis spectrum disorders. In this ocular imaging study, choroidal structure and vascularity were investigated using enhanced depth imaging (EDI) optical coherence tomography (OCT) in first-episode psychosis (FEP), ultra-high risk for psychosis (UHR-P), and age- and gender- matched healthy controls (HCs). There were no significant differences between groups in central choroidal thickness, stromal choroidal area (SCA), luminal choroidal area (LCA) and total subfoveal choroidal area. The LCA/SCA ratio (p<0.001) and the choroidal vascularity index (CVI) (p<0.001) were significantly different between FEP, UHR-P and HCs. CVI and LCA/SCA ratio were significantly higher in patients with FEP compared to help-seeking youth at UHR-P. CVI and LCA/SCA ratio were not different between UHR-P and HCs. However, CVI was higher in UHR-P compared to HCs after excluding the outliers for the sensitivity analysis (p = 0.002). Current findings suggest that choroidal thickness is normal, but there are abnormalities in choroidal microvasculature in prodromal and first-episode psychosis. Further longitudinal studies are needed to investigate oculomics, especially CVI, as a promising biomarker for the prediction of conversion to psychosis in individuals at clinical high-risk.

Cerebral blood flow in schizophrenia: A systematic review and meta-analysis of MRI-based studies

INTRODUCTION

Schizophrenia-spectrum disorders (SSD) represent one of the leading causes of disability worldwide and are usually underpinned by neurodevelopmental brain abnormalities observed on a structural and functional level. Nuclear medicine imaging studies of cerebral blood flow (CBF) have already provided insights into the pathophysiology of these disorders. Recent developments in non-invasive MRI techniques such as arterial spin labeling (ASL) have allowed broader examination of CBF across SSD prompting us to conduct an updated literature review of MRI-based perfusion studies. In addition, we conducted a focused meta-analysis of whole brain studies to provide a complete picture of the literature on the topic.

METHODS

A systematic OVID search was performed in Embase, MEDLINEOvid, and PsycINFO. Studies eligible for inclusion in the review involved: 1) individuals with SSD, first-episode psychosis or clinical-high risk for psychosis, or; 2) had healthy controls for comparison; 3) involved MRI-based perfusion imaging methods; and 4) reported CBF findings. No time span was specified for the database queries (last search: 08/2022). Information related to participants, MRI techniques, CBF analyses, and results were systematically extracted. Whole-brain studies were then selected for the meta-analysis procedure. The methodological quality of each included studies was assessed.

RESULTS

For the systematic review, the initial Ovid search yielded 648 publications of which 42 articles were included, representing 3480 SSD patients and controls. The most consistent finding was that negative symptoms were linked to cortical fronto-limbic hypoperfusion while positive symptoms seemed to be associated with hyperperfusion, notably in subcortical structures. The meta-analysis integrated results from 13 whole-brain studies, across 426 patients and 401 controls, and confirmed the robustness of the hypoperfusion in the left superior and middle frontal gyri and right middle occipital gyrus while hyperperfusion was found in the left putamen.

CONCLUSION

This updated review of the literature supports the implication of hemodynamic correlates in the pathophysiology of psychosis symptoms and disorders. A more systematic exploration of brain perfusion could complete the search of a multimodal biomarker of SSD.

Considerations for Optimizing Warfighter Psychological Health with a Research-Based Flavonoid Approach: A Review

Optimal nutrition is imperative for psychological health. Oxidative stress and inflammation are underlying etiologies for alterations in psychological health. Warfighters are at risk of health concerns such as depression due to increased stress in austere environments and family separation while deployed. Over the last decade, research has demonstrated the health benefits of flavonoids found in fruits and berries. Berry flavonoids have potent antioxidant and anti-inflammatory properties by inhibiting oxidative stress and inflammation. In this review, the promising effects of various berries rich in bioactive flavonoids are examined. By inhibiting oxidative stress, berry flavonoids have the potential to modulate brain, cardiovascular, and intestinal health. There is a critical need for targeted interventions to address psychological health concerns within the warfighter population, and a berry flavonoid-rich diet and/or berry flavonoid dietary supplement intervention may prove beneficial as an adjunctive therapy. Structured searches of the literature were performed in the PubMed, CINAHL, and EMBASE databases using predetermined keywords. This review focuses on berry flavonoids' critical and fundamental bioactive properties and their potential effects on psychological health in investigations utilizing cell, animal, and human model systems.

The Use of Optical Coherence Tomography and Electrophysiological Tests in the Early Diagnosis of Inflammatory Changes in the CNS in children with ASD-A Review of Contemporary Literature

This article is a review of the contemporary literature on the possibility of using modern ophthalmological diagnostics, such as optical coherence tomography and electrophysiological tests, in the assessment of changes in eyesight correlating with inflammatory changes in the central nervous system (CNS) as one of the risk factors for neurodevelopmental disorders in children with ASD. A significant role is attributed to the activation of nerve and glial cells, as well as inflammatory changes in the brain, both of which can be of great importance in regard to an autism development predisposition. This fact indicates the possibility of using certain ophthalmic markers to depict an early correlation between the CNS and its outermost layer, i.e., the retina. A comprehensive ophthalmological assessment, and above all, characteristic changes in the functional function of photoreceptors and disorders of the structures of the retina or optic nerve fibers found in the latest OCT or ERG tests may in the future become diagnostic tools, further confirming the early characteristics of autism in children and adolescents. The above information, therefore, emphasizes the importance of cooperation between specialists in improving the diagnosis and treatment of children with autism.

It takes two to tango: Widening our understanding of the onset of schizophrenia from a neuro-angiogenic perspective

Schizophrenia is a chronic debilitating mental disorder characterized by perturbations in thinking, perception, and behavior, along with brain connectivity deficiencies, neurotransmitter dysfunctions, and loss of gray brain matter. To date, schizophrenia has no cure and pharmacological treatments are only partially efficacious, with about 30% of patients describing little to no improvement after treatment. As in most neurological disorders, the main descriptions of schizophrenia physiopathology have been focused on neural network deficiencies. However, to sustain proper neural activity in the brain, another, no less important network is operating: the vast, complex and fascinating vascular network. Increasing research has characterized schizophrenia as a systemic disease where vascular involvement is important. Several neuro-angiogenic pathway disturbances have been related to schizophrenia. Alterations, ranging from genetic polymorphisms, mRNA, and protein alterations to microRNA and abnormal metabolite processing, have been evaluated in plasma, post-mortem brain, animal models, and patient-derived induced pluripotent stem cell (hiPSC) models. During embryonic brain development, the coordinated formation of blood vessels parallels neuro/gliogenesis and results in the structuration of the neurovascular niche, which brings together physical and molecular signals from both systems conforming to the Blood-Brain barrier. In this review, we offer an upfront perspective on distinctive angiogenic and neurogenic signaling pathways that might be involved in the biological causality of schizophrenia. We analyze the role of pivotal angiogenic-related pathways such as Vascular Endothelial Growth Factor and HIF signaling related to hypoxia and oxidative stress events; classic developmental pathways such as the NOTCH pathway, metabolic pathways such as the mTOR/AKT cascade; emerging neuroinflammation, and neurodegenerative processes such as UPR, and also discuss non-canonic angiogenic/axonal guidance factor signaling. Considering that all of the mentioned above pathways converge at the Blood-Brain barrier, reported neurovascular alterations could have deleterious repercussions on overall brain functioning in schizophrenia.

Genomic modules and intramodular network concordance in susceptible and resilient male mice across models of stress

The multifactorial etiology of stress-related disorders necessitates a constant interrogation of the molecular convergences in preclinical models of stress that use disparate paradigms as stressors spanning from environmental challenges to genetic predisposition to hormonal signaling. Using RNA-sequencing, we investigated the genomic signatures in the ventral hippocampus common to mouse models of stress. Chronic oral corticosterone (CORT) induced increased anxiety- and depression-like behavior in wild-type male mice and male mice heterozygous for the gene coding for brain-derived neurotrophic factor Val66Met, a variant associated with genetic susceptibility to stress. In a separate set of male mice, chronic social defeat stress (CSDS) led to a susceptible or a resilient population, whose proportion was dependent on housing conditions, namely standard housing or enriched environment. Rank-rank-hypergeometric overlap (RRHO), a threshold-free approach that ranks genes by their p value and effect size direction, was used to identify genes from a continuous gradient of significancy that were concordant across groups. In mice treated with CORT and in standard-housed susceptible mice, differentially expressed genes (DEGs) were concordant for gene networks involved in neurotransmission, cytoskeleton function, and vascularization. Weighted gene co-expression analysis generated 54 gene hub modules and revealed two modules in which both CORT and CSDS-induced enrichment in DEGs, whose function was concordant with the RRHO predictions, and correlated with behavioral resilience or susceptibility. These data showed transcriptional concordance across models in which the stress coping depends upon hormonal, environmental, or genetic factors revealing common genomic drivers that embody the multifaceted nature of stress-related disorders.

Gabrb3 endothelial cell-specific knockout mice display abnormal blood flow, hypertension, and behavioral dysfunction

Our recent studies uncovered a novel GABA signaling pathway in embryonic forebrain endothelial cells that works independently from neuronal GABA signaling and revealed that disruptions in endothelial GABA_A receptor-GABA signaling from early embryonic stages can directly contribute to the origin of psychiatric disorders. In the GABA_A receptor β3 subunit endothelial cell conditional knockout (Gabrb3^ECKO) mice, the β3 subunit is deleted selectively from endothelial cells, therefore endothelial GABA_A receptors become inactivated and dysfunctional. There is a reduction in vessel densities and increased vessel morphology in the Gabrb3^ECKO telencephalon that persists in the adult neocortex. Gabrb3^ECKO mice show behavioral deficits such as impaired reciprocal social interactions, communication deficits, heightened anxiety, and depression. Here, we characterize the functional changes in Gabrb3^ECKO mice by evaluating cortical blood flow, examine the consequences of loss of endothelial Gabrb3 on cardiac tissue, and define more in-depth altered behaviors. Red blood cell velocity and blood flow were increased in the cortical microcirculation of the Gabrb3^ECKO mice. The Gabrb3^ECKO mice had a reduction in vessel densities in the heart, similar to the brain; exhibited wavy, myocardial fibers, with elongated 'worm-like' nuclei in their cardiac histology, and developed hypertension. Additional alterations in behavioral function were observed in the Gabrb3^ECKO mice such as increased spontaneous exploratory activity and rearing in an open field, reduced short term memory, decreased ambulatory activity in CLAMS testing, and altered prepulse inhibition to startle, an important biomarker of psychiatric diseases such as schizophrenia. Our results imply that vascular Gabrb3 is a key player in the brain as well as the heart, and its loss in both organs can lead to concurrent development of psychiatric and cardiac dysfunction.

[Features of the parameters of hemodynamics and vascular tone of the brain in patients with depressive disorders]

OBJECTIVE

To study the features of hemodynamics and vascular tone of the brain in patients with depressive disorders.

MATERIAL AND METHODS

Fifty-four patients with depressive disorders and 54 conditionally healthy individuals were examined. The study of hemodynamics and vascular tone of the brain was carried out using rheoelectroencephalography.

RESULTS

Patients with depression in conditions of physiological rest have a statistically significantly higher tone of resistive vessels and medium-caliber arteries, as well as a lower level of elastic properties of the main arteries compared to healthy individuals.

CONCLUSION

The shape of the rheoelectroencephalogram of patients with depressive disorders was characterized by smoothing of the dicrotic wave and its displacement to the top, as well as a slight severity of incisure and an increase in the speed of propagation of the rheographic wave.

NoRCE: non-coding RNA sets cis enrichment tool

BACKGROUND

While some non-coding RNAs (ncRNAs) are assigned critical regulatory roles, most remain functionally uncharacterized. This presents a challenge whenever an interesting set of ncRNAs needs to be analyzed in a functional context. Transcripts located close-by on the genome are often regulated together. This genomic proximity on the sequence can hint at a functional association.

RESULTS

We present a tool, NoRCE, that performs cis enrichment analysis for a given set of ncRNAs. Enrichment is carried out using the functional annotations of the coding genes located proximal to the input ncRNAs. Other biologically relevant information such as topologically associating domain (TAD) boundaries, co-expression patterns, and miRNA target prediction information can be incorporated to conduct a richer enrichment analysis. To this end, NoRCE includes several relevant datasets as part of its data repository, including cell-line specific TAD boundaries, functional gene sets, and expression data for coding & ncRNAs specific to cancer. Additionally, the users can utilize custom data files in their investigation. Enrichment results can be retrieved in a tabular format or visualized in several different ways. NoRCE is currently available for the following species: human, mouse, rat, zebrafish, fruit fly, worm, and yeast.

CONCLUSIONS

NoRCE is a platform-independent, user-friendly, comprehensive R package that can be used to gain insight into the functional importance of a list of ncRNAs of any type. The tool offers flexibility to conduct the users' preferred set of analyses by designing their own pipeline of analysis. NoRCE is available in Bioconductor and https://github.com/guldenolgun/NoRCE .

The Relationship between Carotid Doppler Ultrasound and EEG Metrics in Healthy Preschoolers and Adults

Despite widespread using electroencephalography (EEG) and Doppler ultrasound in pediatric neurology clinical practice, there are still no well-known correlations between these methods that could contribute to a better understanding of brain processes and development of neurological pathology. This study aims to reveal relationship between EEG and Doppler ultrasound methods. We compared two cohorts of adults and preschool children with no history of neurological or mental diseases. The data analysis included investigation of EEG and carotid blood flow indexes, which are significant in neurological diagnosis, as well as calculation of linear and non-linear EEG parameters and ratios between the systolic peak velocities of carotid arteries and carotid blood asymmetry. We have found age-dependent correlations between EEG and power Doppler ultrasound imaging (PDUI) data. Carotid blood flow asymmetry correlated with delta-rhythm power spectral density only in preschoolers. The ratios of blood flow velocities in the internal carotid arteries to those in the common carotid arteries correlated with higher peak alpha frequency and lower fractal dimension; moreover, they were associated with lower Epworth sleepiness scale scores. The study revealed significant correlations between EEG and PDUI imaging indexes, which are different for healthy children and adults. Despite the fact that the correlations were associated with non-clinical states such as overwork or stress, we assumed that the investigated parameters could be applicable for clinical trials.

The Role of Brain Microvascular Endothelial Cell and Blood-Brain Barrier Dysfunction in Schizophrenia

BACKGROUND

Despite decades of research, little clarity exists regarding pathogenic mechanisms related to schizophrenia. Investigations on the disease biology of schizophrenia have primarily focused on neuronal alterations. However, there is substantial evidence pointing to a significant role for the brain's microvasculature in mediating neuroinflammation in schizophrenia.

SUMMARY

Brain microvascular endothelial cells (BMEC) are a central element of the microvasculature that forms the blood-brain barrier (BBB) and shields the brain against toxins and immune cells via paracellular, transcellular, transporter, and extracellular matrix proteins. While evidence for BBB dysfunction exists in brain disorders, including schizophrenia, it is not known if BMEC themselves are functionally compromised and lead to BBB dysfunction.

KEY MESSAGES

Genome-wide association studies, postmortem investigations, and gene expression analyses have provided some insights into the role of the BBB in schizophrenia pathophysiology. However, there is a significant gap in our understanding of the role that BMEC play in BBB dysfunction. Recent advances differentiating human BMEC from induced pluripotent stem cells (iPSC) provide new avenues to examine the role of BMEC in BBB dysfunction in schizophrenia.

Optical Coherence Tomography Angiography of Macula and Optic Nerve in Autism Spectrum Disorder: A Pilot Study

The aim of this study was to compare retinal thicknesses and vascular parameters between autism spectrum disorder (ASD) and neurotypical (NT) individuals. Recruited ASD subjects and age- and sex-matched NT controls underwent 2 optical coherence tomography scans (OCT) (macular cube and optic nerve cube) and 2 OCT angiography (OCTA) scans (macular and optic nerve head (ONH) OCTA) with the device Cirrus 5000 (Zeiss). Concerning OCT, we considered full retina thickness in 9 macular sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) pattern and peripapillary retinal nerve fiber layer (pRNFL) thickness in 4 quadrants and 12 clock-hour sectors. Vessel density and capillary perfusion density in 9 sectors were measured using 6 × 6 mm macular OCTA. Foveal avascular zone (FAZ) parameters were also considered. ONH 4.5 × 4.5 mm OCTA estimated perfusion density and flux index in 4 peripapillary quadrants. Comparisons between groups of all these parameters were performed. ASD subjects showed higher ONH perfusion density and lower ONH flux index at the peripapillary inferior quadrant when compared with NT individuals (p < 0.05). Plus, a trend towards higher macular thicknesses, higher pRNFL thickness at inferior clock-hour sectors and higher macular vessel density and perfusion was observed in ASD. No differences were found in FAZ parameters. In conclusion, retinas of ASD subjects may present some structural and vascular differences when compared with retinas of NT individuals.

A High Polyphenol Diet Improves Psychological Well-Being: The Polyphenol Intervention Trial (PPhIT)

Mental ill health is currently one of the leading causes of disease burden worldwide. A growing body of data has emerged supporting the role of diet, especially polyphenols, which have anxiolytic and antidepressant-like properties. The aim of the present study was to assess the effect of a high polyphenol diet (HPD) compared to a low polyphenol diet (LPD) on aspects of psychological well-being in the Polyphenol Intervention Trial (PPhIT). Ninety-nine mildly hypertensive participants aged 40-65 years were enrolled in a four-week LPD washout period and then randomised to either an LPD or an HPD for eight weeks. Both at baseline and the end of intervention, participants' lifestyle and psychological well-being were assessed. The participants in the HPD group reported a decrease in depressive symptoms, as assessed by the Beck Depression Inventory-II, and an improvement in physical component and mental health component scores as assessed with 36-Item Short Form Survey. No differences in anxiety, stress, self-esteem or body image perception were observed. In summary, the study findings suggest that the adoption of a polyphenol-rich diet could potentially lead to beneficial effects including a reduction in depressive symptoms and improvements in general mental health status and physical health in hypertensive participants.

Sleep, brain vascular health and ageing

Sleep maintains the function of the entire body through homeostasis. Chronic sleep deprivation (CSD) is a prime health concern in the modern world. Previous reports have shown that CSD has profound negative effects on brain vasculature at both the cellular and molecular levels, and that this is a major cause of cognitive dysfunction and early vascular ageing. However, correlations among sleep deprivation (SD), brain vascular changes and ageing have barely been looked into. This review attempts to correlate the alterations in the levels of major neurotransmitters (acetylcholine, adrenaline, GABA and glutamate) and signalling molecules (Sirt1, PGC1α, FOXO, P66^shc, PARP1) in SD and changes in brain vasculature, cognitive dysfunction and early ageing. It also aims to connect SD-induced loss in the number of dendritic spines and their effects on alterations in synaptic plasticity, cognitive disabilities and early vascular ageing based on data available in scientific literature. To the best of our knowledge, this is the first article providing a pathophysiological basis to link SD to brain vascular ageing.

The Association Between Vascular Inflammation and Depressive Disorder. Causality, Biomarkers and Targeted Treatment

Diabetes, obesity, atherosclerosis, and myocardial infarction are frequently co-morbid with major depressive disorder. In the current review, it is argued that vascular inflammation is a factor that is common to all disorders and that an endothelial dysfunction of the blood-brain barrier could be involved in the induction of depression symptoms. Biomarkers for vascular inflammation include a high plasma level of C-reactive protein, soluble cell-adhesion molecules, von Willebrand factor, aldosterone, and proinflammatory cytokines like interleukin-6 or tumor necrosis factor α. A further possible biomarker is flow-mediated dilation of the brachial artery. Treatment of vascular inflammation is expected to prevent or to reduce symptoms of depression. Several tentative treatments for this form of depression can be envisioned: eicosapentaenoic acid (EPA), valproate, Vagus-nerve stimulation, nicotinic α7 agonists, and agonists of the cannabinoid CB₂-receptor.

Vascular Integrity and Signaling Determining Brain Development, Network Excitability, and Epileptogenesis

Our understanding of the etiological mechanisms leading up to epilepsy has undergone radical changes over time due to more insights into the complexity of the disease. The traditional hypothesis emphasized network hyperexcitability and an imbalance of inhibition and excitation, eventually leading to seizures. In this context, the contribution of the vascular system, and particularly the interactions between blood vessels and neuronal tissue, came into focus only recently. Thus, one highly exciting causative or contributing factor of epileptogenesis is the disruption of the blood-brain barrier (BBB) in the context of not only posttraumatic epilepsy, but also other etiologies. This hypothesis is now recognized as a synergistic mechanism that can give rise to epilepsy, and BBB repair for restoration of cerebrovascular integrity is considered a therapeutic alternative. Endothelial cells lining the inner surface of blood vessels are an integral component of the BBB system. Sealed by tight junctions, they are crucial in maintaining homeostatic activities of the brain, as well as acting as an interface in the neurovascular unit. Additional potential vascular mechanisms such as inflammation, altered neurovascular coupling, or changes in blood flow that can modulate neuronal circuit activity have been implicated in epilepsy. Our own work has shown how intrinsic defects within endothelial cells from the earliest developmental time points, which preclude neuronal changes, can lead to vascular abnormalities and autonomously support the development of hyperexcitability and epileptiform activity. In this article, we review the importance of vascular integrity and signaling for network excitability and epilepsy by highlighting complementary basic and clinical research studies and by outlining possible novel therapeutic strategies.

Examination of retinal vascular trajectory in schizophrenia and bipolar disorder

AIM

Evidence suggests microvascular dysfunction (wider retinal venules and narrower arterioles) in schizophrenia (SCZ) and bipolar disorder (BD). The vascular development is synchronous with neuronal development in the retina and brain. The retinal vessel trajectory is related to retinal nerve fiber layer thinning and cerebrovascular abnormalities in SCZ and BD and has not yet been examined. Hence, in this study we examined the retinal vascular trajectory in SCZ and BD in comparison with healthy volunteers (HV).

METHODS

Retinal images were acquired from 100 HV, SCZ patients, and BD patients, respectively, with a non-mydriatic fundus camera. Images were quantified to obtain the retinal arterial and venous trajectories using a validated, semiautomated algorithm. Analysis of covariance and regression analyses were conducted to examine group differences. A supervised machine-learning ensemble of bagged-trees method was used for automated classification of trajectory values.

RESULTS

There was a significant difference among groups in both the retinal venous trajectory (HV: 0.17 ± 0.08; SCZ: 0.25 ± 0.17; BD: 0.27 ± 0.20; P < 0.001) and the arterial trajectory (HV: 0.34 ± 0.15; SCZ: 0.29 ± 0.10; BD: 0.29 ± 0.11; P = 0.003) even after adjusting for age and sex (P < 0.001). On post-hoc analysis, the SCZ and BD groups differed from the HV on retinal venous and arterial trajectories, but there was no difference between SCZ and BD patients. The machine learning showed an accuracy of 86% and 73% for classifying HV versus SCZ and BD, respectively.

CONCLUSION

Smaller trajectories of retinal arteries indicate wider and flatter curves in SCZ and BD. Considering the relation between retinal/cerebral vasculatures and retinal nerve fiber layer thinness, the retinal vascular trajectory is a potential marker for SCZ and BD. As a relatively affordable investigation, retinal fundus photography should be further explored in SCZ and BD as a potential screening measure.