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The axon initial segment (AIS) constitutes not only the site of action potential initiation, but also a hub for activity-dependent modulation of output generation. Recent studies shedding light on AIS function used predominantly post-hoc approaches since no robust murine in vivo live reporters exist. Here, we introduce a reporter line in which the AIS is intrinsically labeled by an ankyrin-G-GFP fusion protein activated by Cre recombinase, tagging the native Ank3 gene. Using confocal, superresolution, and two-photon microscopy as well as whole-cell patch-clamp recordings in vitro, ex vivo, and in vivo, we confirm that the subcellular scaffold of the AIS and electrophysiological parameters of labeled cells remain unchanged. We further uncover rapid AIS remodeling following increased network activity in this model system, as well as highly reproducible in vivo labeling of AIS over weeks. This novel reporter line allows longitudinal studies of AIS modulation and plasticity in vivo in real-time and thus provides a unique approach to study subcellular plasticity in a broad range of applications.
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The advent of super-resolution microscopy has opened up new avenues to unveil brain structures with unprecedented spatial resolution in the living state. Yet, its application to live animals remains a genuine challenge. Getting optical access to the brain in vivo requires the use of a 'cranial window', whose mounting greatly influences image quality. Indeed, the coverslip used for the cranial window should lie as orthogonal as possible to the optical axis of the objective, or else significant optical aberrations occur. In this work, we assess the effect of the tilt angle of the coverslip on STED and two-photon microscopy, in particular, image brightness and spatial resolution. We then propose an approach to measure and reduce the tilt using a simple device added to the microscope, which can ensure orthogonality with a precision of 0.07°.
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Significance: Stimulated emission depletion (STED) microscopy has been used to address a wide range of neurobiological questions in optically well-accessible samples, such as cell culture or brain slices. However, the application of STED to deeply embedded structures in the brain of living animals remains technically challenging. Aim: In previous work, we established chronic STED imaging in the hippocampus in vivo but the gain in spatial resolution was restricted to the lateral plane. In our study, we report on extending the gain in STED resolution into the optical axis to visualize dendritic spines in the hippocampus in vivo. Approach: Our approach is based on a spatial light modulator to shape the focal STED light intensity in all three dimensions and a conically shaped window that is compatible with an objective that has a long working distance and a high numerical aperture. We corrected distortions of the laser wavefront to optimize the shape of the bottle beam of the STED laser. Results: We show how the new window design improves the STED point spread function and the spatial resolution using nanobeads. We then demonstrate the beneficial effects for 3D-STED microscopy of dendritic spines, visualized with an unprecedented level of detail in the hippocampus of a living mouse. Conclusions: We present a methodology to improve the axial resolution for STED microscopy in the deeply embedded hippocampus in vivo, facilitating longitudinal studies of neuroanatomical plasticity at the nanoscale in a wide range of (patho-)physiological contexts.
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We present a computational framework to simultaneously perform image acquisition, reconstruction, and analysis in the context of open-source microscopy automation. The setup features multiple computer units intersecting software with hardware devices and achieves automation using python scripts. In practice, script files are executed in the acquisition computer and can perform any experiment by modifying the state of the hardware devices and accessing experimental data. The presented framework achieves concurrency by using multiple instances of ImSwitch and napari working simultaneously. ImSwitch is a flexible and modular open-source software package for microscope control, and napari is a multidimensional image viewer for scientific image analysis. The presented framework implements a system based on file watching, where multiple units monitor a filesystem that acts as the synchronization primitive. The proposed solution is valid for any microscope setup, supporting various biological applications. The only necessary element is a shared filesystem, common in any standard laboratory, even in resource-constrained settings. The file watcher functionality in Python can be easily integrated into other python-based software. We demonstrate the proposed solution by performing tiling experiments using the molecular nanoscale live imaging with sectioning ability (MoNaLISA) microscope, a high-throughput super-resolution microscope based on reversible saturable optical fluorescence transitions (RESOLFT).
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There are many complex concepts to consider during end-of-life discussions and advance care planning, especially when vulnerable populations such as older individuals with serious mental illness are involved. This article aims to summarize some of these important concepts, such as the effects of ageism, preservation of human rights and dignity, supported or shared decision making and palliative approaches. It emerged from a study that found two thirds of 100 participants 60 years of age and older with serious mental illness had end-of-life decision-making capacity. This finding highlighted the individual and contextual nature of decision-making capacity, the importance of consideration of individual values and protection of human dignity during end-of-life care. Healthcare providers have a duty to initiate end-of-life and advance care discussions, to optimize decision-making capacity, and to protect autonomous decision-making. Chronological age or diagnostic categories should never be used as reasons for discrimination and all patients should receive end-of-life care in keeping with their preferences and values.
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Background: In psychiatry, there is still a lack of objective biological diagnostic measurements. It is important to investigate measurements or symptom dimensions that can inform diagnostic assessments and allow for a more personalised approach to patients. Aim: To discuss how early deviant behaviour (EDB) may be seen as a possible continuous symptom dimension trait and endophenotype in schizophrenia. Methods: Conducting a commentary review by highlighting some important findings from available literature. Results: Findings regarding EDB in schizophrenia in a South African genetic sample point towards EDB as a progressive subtype of schizophrenia, with very early onset of illness (even prior to the psychotic symptomatology) and a genetic form of illness. Conclusion: Valuable information can be gained by enquiring into EDB and viewing it as a continuous symptom dimension trait and endophenotype during the psychiatric diagnostic interview.
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Background: The study's main aim was to assess the end-of-life decision-making capacity and health-related values of older people with serious mental illness. Methods: A cross-sectional, observational study, was done at Weskoppies Psychiatric Hospital, Gauteng Province, South Africa that included 100 adults older than 60 years of age and diagnosed with serious mental illness. The Mini-Cog and a semi-structured clinical assessment of end-of-life decision-making capacity was done before a standardized interview, Assessment of Capacity to Consent to Treatment, was administered. This standardized instrument uses a hypothetical vignette to assess decision-making capacity and explores healthcare-related values. Results: The Assessment of Capacity to Consent to Treatment scores correlated (p < 0.001) with the outcomes of the semi-structured decision-making capacity evaluation. Significant correlations with impaired decision-making capacity included: lower scores on the Mini-Cog (p < 0.001); a duration of serious mental illness of 30-39 years (p = 0025); having a diagnosis of schizophrenia spectrum disorders (p = 0.0007); and being admitted involuntarily (p < 0.0001). A main finding was that 65% of participants had decision-making capacity for end-of-life decisions, were able to express their values and engage in advance care discussions. Discussion and Conclusion: Healthcare providers have a duty to initiate advance care discussions, optimize decision-making capacity, and protect autonomous decision-making. Many older patients with serious mental illness can engage in end-of-life discussions and can make autonomous decisions about preferred end-of-life care. Chronological age or diagnostic categories should never be used as reasons for discrimination, and older people with serious mental illness should receive end-of-life care in keeping with their preferences and values.
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BACKGROUND: Occupational therapists have been using group therapy as their preferred treatment modality in mental healthcare since the origin of the profession. In private mental healthcare units, major depressive disorder (MDD) is the most common psychiatric disease. Occupational therapists use individual and group therapy to treat adult inpatients with MDD. Little is known about the perceptions and experiences of adult inpatients with MDD regarding occupational therapy activity-based groups. AIM: To describe the perceptions and experiences of adult psychiatric inpatients with MDD towards occupational therapy activity-based groups. This article reports on the perceptions of adult psychiatric inpatients with MDD, which formed part of a larger study. SETTING: The study took place at two private general hospitals in Gauteng province, South Africa, each with a psychiatric ward. METHODS: The researcher used a qualitative explorative descriptive design. Accessible participants were selected using convenience sampling. Only consenting participants took part in the study. Data were collected during focus group discussions. Data were thematically analysed. RESULTS: Participants' perceptions could be placed into one of four themes: (1) experience improved mood, (2) learned coping skills, (3) regained self-esteem and (4) becoming part of the solution to face life challenges. CONCLUSION: Activities that are unique to occupational therapy profession can benefit inpatients with MDD. This supports the profession's historical beliefs, assumptions and foundations regarding therapeutic use of activities. According to these inpatients, group activities improved their overall mental health.
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ACBD5 deficiency is a novel peroxisome disorder with a largely uncharacterized pathology. ACBD5 was recently identified in a tethering complex mediating membrane contacts between peroxisomes and the endoplasmic reticulum (ER). An ACBD5-deficient mouse was analyzed to correlate ACBD5 tethering functions with the disease phenotype. ACBD5-deficient mice exhibit elevated very long-chain fatty acid levels and a progressive cerebellar pathology. Liver did not exhibit pathologic changes but increased peroxisome abundance and drastically reduced peroxisome-ER contacts. Lipidomics of liver and cerebellum revealed tissue-specific alterations in distinct lipid classes and subspecies. In line with the neurological pathology, unusual ultra-long chain fatty acids (C > 32) were elevated in phosphocholines from cerebelli but not liver indicating an organ-specific imbalance in fatty acid degradation and elongation pathways. By contrast, ether lipid formation was perturbed in liver towards an accumulation of alkyldiacylglycerols. The alterations in several lipid classes suggest that ACBD5, in addition to its acyl-CoA binding function, might maintain peroxisome-ER contacts in order to contribute to the regulation of anabolic and catabolic cellular lipid pathways.
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Proteínas de Transporte , Cerebelo/metabolismo , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cerebelo/patologia , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Feminino , Homeostase/genética , Fígado/patologia , Masculino , Camundongos , Camundongos Knockout , Transtornos Peroxissômicos , Peroxissomos/genética , Peroxissomos/metabolismoRESUMO
BACKGROUND: Schizophrenia is a severe mental disorder with profound effects on a person's life. In addition to the psychiatric symptoms, patients with schizophrenia generally have multiple somatic comorbidities, such as cardiovascular and metabolic disorders. The general practitioner (GP) is of key importance for the patient's continuous care and holistic wellbeing. OBJECTIVE: The aim of this article is to emphasise the role of GPs in embracing physical exercise as add-on treatment to antipsychotic medications, and to illustrate the value of exercise for people with schizophrenia by summarising the effects on the psychiatric symptoms, neuroanatomical and neurochemical characteristics, and general physiological and psychological health. DISCUSSION: Physical exercise can lead to improvements in positive, negative and cognitive symptoms, as well as in somatic comorbidities, global functioning and quality of life. Physical exercise can be a valuable add-on intervention for people with schizophrenia. The GP is essential for prescribing and following up on exercise tailored for the individual.
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Exercício Físico/psicologia , Esquizofrenia/terapia , Humanos , Qualidade de Vida/psicologia , Esquizofrenia/complicaçõesRESUMO
Medical practitioners are confronted daily with decisions about patients' capacity to consent to interventions. To address some of the pertinent issues with these assessments, the end-of-life decision-making capacity of a 72-year-old female with treatment-resistant schizophrenia and terminal cancer is discussed, as are the role of the treating clinician and the importance of health-related values. There is a recommendation that the focus of these assessments can rather be on practical outcomes, especially when capacity issues arise. This implies that the decision-making capacity of the patient is only practically important when the treatment team is willing to proceed against the patient's wishes. This shifts the focus from a potentially difficult assessment to the simpler question of whether the patient's capacity will change the treatment approach. Clinicians should attend to any possible underlying issues, instead of focusing strictly on capacity. Compared to the general populations people with serious mental illness (SMI) have higher rates of physical illness and die at a younger age, but they do not commonly access palliative care services. Conversations about end-of-life care can occur without fear that a person's psychiatric symptoms or related vulnerabilities will undermine the process. More research about palliative care and advance care planning for people with SMI is needed. This is even more urgent in light of the coronavirus disease-2019 (COVID-19) pandemic, and South African health services should consider recommendations that advanced care planning should be routinely implemented. These recommendations should not only focus on the general population and should include patients with SMI.
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Tomada de Decisões , Competência Mental/psicologia , Neoplasias/psicologia , Psicologia do Esquizofrênico , Assistência Terminal/psicologia , Idoso , Betacoronavirus , COVID-19 , Infecções por Coronavirus/psicologia , Feminino , Humanos , Consentimento Livre e Esclarecido/psicologia , Pandemias , Pneumonia Viral/psicologia , SARS-CoV-2 , EsquizofreniaRESUMO
BACKGROUND: Schizophrenia is a heterogeneous disorder with strong genetic vulnerability. Family history of schizophrenia has been considered in genetic studies under several models. De novo genetic events seem to play a larger role in sporadic cases. AIM: This study used the familial-sporadic distinction with the aim of identifying a more homogeneous phenotype to delineate the genetic and clinical complexity of schizophrenia. SETTING: The study was conducted at Weskoppies Hospital, Pretoria, South Africa. METHODS: The study included 384 participants with schizophrenia or schizoaffective disorder from the Afrikaner founder population in South Africa who are considered comparable to Caucasian patients from the United States. A comprehensive data capturing sheet was completed. RESULTS: When schizophrenia and schizoaffective disorder diagnoses were considered jointly, we found no significant differences between the sporadic and the familial groups for age at disease onset, season of birth, comorbid diagnoses, clinical symptomatology, history of suicide or marital status. When the diagnoses were examined separately, however, the sporadic schizoaffective disorder, bipolar type, was found to have a significantly lower age at onset (mean 20.6 vs. 25.3 years). CONCLUSION: The sporadic schizoaffective disorder, bipolar type, forms a more homogeneous subgroup for genetic studies.
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Knowledge on cortical development is based mainly on small rodents besides primates and carnivores, all being altricial nestlings. Ungulates are precocial and born with nearly mature sensory and motor systems. Almost no information is available on ungulate brain development. Here, we analyzed European wild boar cortex development, focusing on the neuropeptide Y immunoreactive (NPY-ir) neuron system in dorsoparietal cortex from E35 to P30. Transient NPY-ir neuron types including archaic cells of the cortical plate and axonal loop cells of the subplate which appear by E60 concurrent with the establishment of the ungulate brain basic sulcal pattern. From E70, NPY-ir axons have an axon initial segment which elongates and shifts closer towards the axon's point of origin until P30. From E85 onwards (birth at E114), NPY-ir neurons in cortical layers form basket cell-like local and Martinotti cell-like ascending axonal projections. The mature NPY-ir pattern is recognizable at E110. Together, morphologies are conserved across species, but timing is not: in pig, the adult pattern largely forms prenatally.
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Neocórtex/embriologia , Neurônios/fisiologia , Neuropeptídeo Y/metabolismo , Animais , Axônios , Feminino , Masculino , Neocórtex/citologia , Neurônios/citologia , Neurônios/metabolismo , Sus scrofa/embriologiaRESUMO
The microdomain that orchestrates action potential initiation in neurons is the axon initial segment (AIS). It has long been considered to be a rather homogeneous domain at the very proximal axon hillock with relatively stable length, particularly in cortical pyramidal cells. However, studies in other brain regions paint a different picture. In hippocampal CA1, up to 50% of axons emerge from basal dendrites. Further, in about 30% of thick-tufted layer V pyramidal neurons in rat somatosensory cortex, axons have a dendritic origin. Consequently, the AIS is separated from the soma. Recent in vitro and in vivo studies have shown that cellular excitability is a function of AIS length/position and somatodendritic morphology, undermining a potentially significant impact of AIS heterogeneity for neuronal function. We therefore investigated neocortical axon morphology and AIS composition, hypothesizing that the initial observation of seemingly homogeneous AIS is inadequate and needs to take into account neuronal cell types. Here, we biolistically transfected cortical neurons in organotypic cultures to visualize the entire neuron and classify cell types in combination with immunolabeling against AIS markers. Using confocal microscopy and morphometric analysis, we investigated axon origin, AIS position, length, diameter as well as distance to the soma. We find a substantial AIS heterogeneity in visual cortical neurons, classified into three groups: (I) axons with somatic origin with proximal AIS at the axon hillock; (II) axons with somatic origin with distal AIS, with a discernible gap between the AIS and the soma; and (III) axons with dendritic origin (axon-carrying dendrite cell, AcD cell) and an AIS either starting directly at the axon origin or more distal to that point. Pyramidal cells have significantly longer AIS than interneurons. Interneurons with vertical columnar axonal projections have significantly more distal AIS locations than all other cells with their prevailing phenotype as an AcD cell. In contrast, neurons with perisomatic terminations display most often an axon originating from the soma. Our data contribute to the emerging understanding that AIS morphology is highly variable, and potentially a function of the cell type.
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The clinical characteristics of an Afrikaner founder population sample recruited for a schizophrenia genetic study are described. Comparisons on several clinical characteristics between this sample and a U.S. sample of schizophrenia patients show that generalization of findings in a founder population to the population at large is applicable. The assessment of the frequency of the 22q11 deletion in Afrikaner schizophrenia patients is approximately 2%, similar to findings in a U.S. sample. Results of analysis of early non-psychotic deviant behavior in subjects under the age of 10 years in the Afrikaner population broadly replicated findings in a U.S. sample. Approximately half of male schizophrenia patients and a quarter of female patients in the Afrikaner schizophrenia database used or abused cannabis. Male users of cannabis with severe early deviant behavior had the lowest mean age of criteria onset, namely 18.4 years. These findings confirm previous findings, indicating that early deviance is linked to later outcome of disease. The clinical characteristics and premorbid variables in 12 childhood-onset Afrikaner schizophrenia patients thus far recruited in this study compare favorably with what is known about childhood-onset schizophrenia in a U.S. sample. The prevalence of co-morbid OCD/OCS in this Afrikaner schizophrenia founder sample was 13.2% which is in keeping with that of co-morbid OCD in schizophrenia, estimated at 12.2% by the U.S. National Institute of Mental Health. These findings confirm that the clinical characteristics of a schizophrenia sample drawn from the Afrikaner founder population can be generalized to the schizophrenia population at large when compared to findings reported in the literature.