In vivo 3D morphology of astrocyte–vasculature interactions in the somatosensory cortex: implications for neurovascular coupling

Astrocytes are increasingly believed to play an important role in neurovascular coupling. Recent in vivo studies have shown that intracellular calcium levels in astrocytes correlate with reactivity in adjacent diving arterioles. However, the hemodynamic response to stimulation involves a complex orchestration of vessel dilations and constrictions that spread rapidly over wide distances. In this work, we study the three-dimensional cytoarchitecture of astrocytes and their interrelations with blood vessels down through layer IV of the mouse somatosensory cortex using in vivo two-photon microscopy. Vessels and astrocytes were visualized through intravenous dextran-conjugated fluorescein and cortically applied sulforhodamine 101 (SR101), respectively. In addition to exploring astrocyte density, vascular proximity, and microvascular density, we found that sheathing of subpial vessels by astrocyte processes was continuous along all capillaries, arterioles, and veins, comprising a highly interconnected pathway through which signals could feasibly be relayed over long distances via gap junctions. An inner SR101-positive sheath noted along pial and diving arterioles was determined to be nonastrocytic, and appears to represent selective SR101 staining of arterial endothelial cells. Our findings underscore the intimate relationship between astrocytes and all cortical blood vessels, and suggest that astrocytes could influence neurovascular regulation at a range of sites, including the capillary bed and pial arterioles.     

Disability pension for psychiatric disorders: Regional differences in Norway 1988–2000

The aim of this study was to describe regional differences in the incidence of disability pensions (DPs) with psychiatric diagnoses, and to determine whether these differences were related to age and/or gender. We compared the incidence rates of new DPs including all diagnoses, with DP with psychiatric diagnoses in Norwegian regions from 1988 to 2000. The population at risk was all individuals aged 16–67 in each year. Individuals already on DP were excluded. Cases were collected from the Norwegian National Insurance Administration. The results showed that the incidence rate ratio (IRR; Norway reference) for DP with psychiatric diagnoses was most elevated for men 1.41 (95% CI 1.27–1.58) and women 1.48 (95% CI 1.34–1.64) living in the most rural region. Men in the urban area had a higher IRR, 1.33 (95% CI 1.26–1.40), than urban women, 1.02 (95% CI 0.96–1.07). The incidence more than doubled in the youngest age group (16–29?years) and decreased in the oldest age group (60–67?years) between 1988 and 2000. The findings conclude that individuals living in semi-rural regions of Norway are more likely to receive a DP with a psychiatric diagnosis than those living in urban areas. Large gender differences were found in the urban area. Further research is needed to investigate the impact of the psychiatric healthcare system and access to rehabilitation on psychiatric disability.     

Frontal–striatal connectivity and positive symptoms of schizophrenia: implications for the mechanistic basis of prefrontal rTMS

European Archives of Psychiatry and Clinical Neuroscience - Repetitive transcranial magnetic stimulation (rTMS), when applied to left dorsolateral prefrontal cortex (LDLPFC), reduces negative...     

Gene–environment interactions in common mental disorders: an update and strategy for a genome-wide search

A decade of research has demonstrated the explanatory potential of interplay between genetic variants and environmental factors in the development of common mental disorders. Initial findings have undergone tests of replicability and specificity. Some gene–environment interactions have been confirmed, some have not replicated and yet other turned out to be more specific than initially thought. Specific and complementary roles of genetic factors have been delineated: a common functional length polymorphism in the serotonin transporter gene (5-HTTLPR) moderated the effect of childhood maltreatment on chronic depression in adulthood, but did not substantially influence the effects of adult stressful life events on the onset of new depressive episodes; in contrast, a common functional polymorphism in the brain-derived neurotrophic factor gene (BDNF) moderated the effect of stressful life events in adulthood in triggering new depressive episodes, but did not influence the effects of childhood maltreatment. Molecular mechanisms underlying gene–environment interactions are being uncovered, including DNA methylation and other epigenetic modifications. New gene–environment interactions continue to be reported, still largely from hypothesis-driven research. Statistical and biological prioritization strategies are proposed to facilitate a systematic discovery of novel gene–environment interactions in genome-wide analyses.     

Sex differences in oxytocin and vasopressin: implications for autism spectrum disorders?

Autism spectrum disorders (ASD) are male-biased and characterized by deficits in social behavior and social communication, excessive anxiety or hyperreactivity to stressful experiences, and a tendency toward repetitiveness. The purpose of this review is to consider evidence for a role for two sexually dimorphic neuropeptides, oxytocin (OT) and arginine vasopressin (VP), in these features of ASD. Both VP and OT play a role in normal development. VP is androgen-dependent and of particular importance to male behavior. Excess VP or disruptions in the VP system could contribute to the male vulnerability to ASD. Alternatively, protective processes mediated via OT or the OT receptor might help to explain the relatively rare occurrence of ASD in females. Disruptions in either OT or VP or their receptors could result from genetic variation or epigenetic modifications of gene expression, especially during early development. Deficits in other developmental growth factors, such as reelin, which may in turn regulate or be regulated by OT or VP, are additional candidates for a role in ASD.     

Deficits in social cognition: a marker for psychiatric disorders?

Research on social cognition focuses on several human abilities with a huge diversity in the approaches to tap the different functions. Empathy, for instance, is a rather elaborated human ability, and several recent studies point to significant impairments in patients suffering from psychiatric disorders, such as schizophrenia or autism. Neuroimaging data from these patients commonly indicate neural dysfunctions accompanying the behavioral deficits. Studying the neural correlates of social cognition is of particular importance, because deficits in these domains may explain the major dysfunctions in psychiatric disorders that prevent effective (re) integration into work and social life. It has also become clearer that social cognition deficits, similar to emotion dysfunctions, may represent trait markers and endophenotypes of the diseases. However, there are several challenges for future studies on social cognitive dysfunctions: on the one hand, the complexity of the constructs and thus the variety of definitions which make it hard to develop adequate tasks. On the other hand, results are needed that particularly address the disorder specificity of these impairments, as well as their potential as endophenotypes via analyzing people at high-risk and their relatives.     

Structural integrity of the limbic–prefrontal connection: Neuropathological correlates of anxiety in Williams syndrome

Williams syndrome (WS) is a genetic condition characterized by a hypersocial personality and desire to form close relationships, juxtaposed with significant anxieties of nonsocial events. The neural underpinnings of anxiety in individuals with WS are currently unknown. Aberrations in the anatomical and microstructural integrity of the uncinate fasciculus (UF) have been recently implicated in social and generalized anxiety disorders. Based on these findings, we tested the hypothesis that the reported anxieties in individuals with WS share similar neuropathological correlates. Toward this end, diffusion tensor imaging (DTI) methods were employed to examine the microstructural integrity (fractional anisotropy, mean diffusivity, longitudinal diffusivity) of the UF in 18 WS and 15 typically developing adults (TD). Anxiety and sociability questionnaires were administered to determine associations with DTI indices of UF across groups. Results revealed comparable white matter integrity of the UF across groups, yet elevated subjective experience of anxiety in those with WS. Additionally, sociability and UF microstructural properties were dissociated across both groups. Whereas no relationships were found between DTI indices and anxiety in TD participants, strong negative associations were observed between these constructs in individuals with WS. Findings indicated that increased anxiety manifested by individuals with WS was associated with DTI measures of the UF and may signal structural or possibly physiological aberration involving this tract within the prefrontal-temporal network.     

Functional coupling of M1 muscarinic acetylcholine receptor to Gαq/11 in dorsolateral prefrontal cortex from patients with psychiatric disorders: a postmortem study

European Archives of Psychiatry and Clinical Neuroscience - Accumulating studies have implicated intracellular signaling through muscarinic acetylcholine receptors (mAChRs) in psychiatric illness....     

Pain perception in patients with chronic disorders of consciousness: What can limbic system tell us?

Objective

Although it is believed that patients with Unresponsive Wakefulness Syndrome (UWS) do not feel pain, recent neuroimaging and neurophysiologic studies have demonstrated some residual traces of nociceptive processing.

Cannabis use and psychiatric and cogitive disorders: the chicken or the egg?

PURPOSE OF REVIEW: Cannabis is the world's most commonly used illicit drug. In this review, we consider the recent literature on the effects of cannabis on mental health and on cognition. RECENT FINDINGS: Cannabis use in adolescence increases the risk of later schizophrenia-like psychoses, especially in genetically vulnerable individuals. Not surprisingly, patients already suffering from psychosis who use cannabis have a worse outcome than those who do not. These effects of cannabis may be consequent on its impact on the dopamine system. There is less evidence of cannabis playing an aetiological role in other mental disorders including depression, but there have been far fewer studies. Heavy cannabis use has also been shown to affect memory and learning performance, both in healthy individuals and in patients suffering from psychosis. Combined cognitive-behavioural therapy and motivational interviewing seems a promising psychological intervention to achieve a cessation of cannabis use in patients suffering from schizophrenia. SUMMARY: Further research is needed to understand the biological mechanisms underlying the effects of cannabis on mental health, but intervention strategies to help patients abstain should currently be implemented in psychiatric services, and public education campaigns should be directed at increasing awareness of the health risks of cannabis.     

Regulation of β_2-adrenoceptors in brain glia: implications for neuroinflammatory and degenerative disorders

正Noradrenaline:Within the central nervous system (CNS), the primary source of the catecholamine neurotransmitter noradrenaline is the locus coeruleus (LC) in the pontine tegmentum, with LC neurons projecting to almost all regions of the brain and spinal cord. Following its release from LC neurons, noradrenaline has     

Epilepsies and neuronal plasticity: for better or for worse?

Extensive experimental investigations have confirmed that "seizures beget seizures." Thus, in adults, limbic seizures lead to cell loss, followed by the formation of novel excitatory synapses that contribute to generating further seizures. The triggering signal is an enhancement of synaptic efficacy, followed by a molecular cascade that triggers axonal sprouting. New synapses are aberrant, since they are formed in regions in which they are not present in controls. They also involve receptors that are not present in controls, and this facilitates the generation of seizures. Therefore, an aberrant form of reactive neuronal plasticity provides a substrate for the long-lasting sequelae of seizures. Since these events take place in brain structures involved in integrative and mnemonic functions, they will have an important impact. Reactive plasticity is documented for other insults and disorders, and may be the basis for the long-term progression of neurodegenerative disorders.     

Stereotactic multi-target limbic leucotomy for treating intractable psychiatric disease in 30 patients☆ Three-year follow-up of memory, intelligence, and psychiatric symptoms

BACKGROUND： The biochemical hypothesis of dopamine hyperfunction in the brain can explain the pathological mechanisms of schizophrenia. Surgery is performed based on limbic system circuit theory correspondence to above-mentioned hypothesis. Stereotactic surgery for the treatment of mental disorders is related to stereotactic surgery that influences the Papez circuit. OBJECTIVE： To observe the effects of stereotactic multi-target limbic leucotomy on the improvements in memory, intelligence and psychiatric symptoms in the treatment of intractable psychiatric disease. DESIGN： Self-control case analysis and follow-up of therapeutic effects. SETTING： Department of Neurosurgery, First Hospital, Hebei Medical University. PARTICIPANTS： Thirty patients with intractable psychiatric disease, who received stereotactic surgery in the Department of Neurosurgery, First Hospital, Hebei Medical University between July 2002 and August 2005, were included in this study. The patients, 21 males and 9 females, all met the diagnostic criteria of intractable psychiatric disease, determined by the national psychosurgery cooperation team in 1998. Informed consents for surgery and clinical follow-up exams were obtained from patients and/or patients＇ relatives （guardians）. METHODS： In 30 patients with intractable psychiatric disease, limbic leucotomy was performed by stereotactic technique. Multi-target radiofrequency hyperthermia was performed in the intracranial amygdaloid nucleus, anterior limb of internal capsule, callosal gyrus, among other regions. The therapeutic effects of patients were evaluated by Brief Psychiatric Rating Scale （BPRS） before surgery, and 6 months, 1, and 3 years after surgery. The Wechsler Adult Intelligence Scale （WAIS） and Clinical Memory Scale （CMS） were used to assess memory and intelligence before and after surgery. MAIN OUTCOME MEASURES： Memory, intelligence, and psychiatric symptoms of patients before and after operation. RESULTS： Thirty patients were included in the final     

An age-period-cohort analysis for prevalence of common psychiatric disorders in Japan, 1999–2017

Purpose

This study aimed to analyze the prevalence of common psychiatric disorders in Japan via an age-period-cohort (APC) analysis.

Methods

Data were used on the prevalence of schizophrenia, schizotypal, and delusional disorders; mood [affective] disorders (mood disorders, hereafter); and neurotic, stress-related, and somatoform disorders from the 1999–2017 Patient Survey in Japan. The age group was defined as 20–89 years with 5-year increments; the cohort was assigned for each age group of each year with a 1-year shift. A Bayesian APC analysis was used to decompose changes in prevalence into three effects: age, period, and cohort.

Results

The APC analysis revealed that the peaks of age effect varied among sexes and diseases. The period effects for all the diseases showed increasing trends over the analyzed years. Although the cohort effect for the prevalence of schizophrenia, schizotypal, and delusional disorders increased until the 1960s, it decreased afterwards. On the other hand, the cohort effects for the prevalence of mood disorders and neurotic, stress-related, and somatoform disorders increased from around the 1950s, and it indicates the prevalence increased particularly in young ages over the years. Also, the trends of each effect were relatively similar between mood disorders and neurotic, stress-related, and somatoform disorders.

Conclusion

Increase in public awareness and psychological stress associated with a change in a social environment is thought to affect the period and cohort effects on the prevalence of mood disorders and neurotic, stress-related, and somatoform disorders.