Advances in tau biology and the difficulties of amyloid-directed immunotherapeutics have heightened interest in tau as a target for small molecule drug discovery for neurodegenerative diseases. Here, we evaluated OLX-07010, a small molecule inhibitor of tau self-association, for the prevention of tau aggregation. The primary endpoint of the study was statistically significant reduction of insoluble tau aggregates in treated JNPL3 mice compared with Vehicle-control mice. Secondary endpoints were dose-dependent reduction of insoluble tau aggregates, reduction of phosphorylated tau, and reduction of soluble tau. This study was performed in JNPL3 mice, which are representative of inherited forms of 4-repeat tauopathies with the P301L tau mutation (e.g., progressive supranuclear palsy and frontotemporal dementia). The P301L mutation makes tau prone to aggregation; therefore, JNPL3 mice present a more challenging target than mouse models of human tau without mutations. JNPL3 mice were treated from 3 to 7 months of age with Vehicle, 30 mg/kg compound dose, or 40 mg/kg compound dose. Biochemical methods were used to evaluate self-associated tau, insoluble tau aggregates, total tau, and phosphorylated tau in the hindbrain, cortex, and hippocampus. The Vehicle group had higher levels of insoluble tau in the hindbrain than the Baseline group; treatment with 40 mg/kg compound dose prevented this increase. In the cortex, the levels of insoluble tau were similar in the Baseline and Vehicle groups, indicating that the pathological phenotype of these mice was beginning to emerge at the study endpoint and that there was a delay in the development of the phenotype of the model as originally characterized. No drug-related adverse effects were observed during the 4-month treatment period.

To date, few studies have explored the specific risk factors of patients with listeriosis who develop rhombencephalitis, and there is insufficient information regarding imaging findings and clinical symptoms in patients with this disease. This work aimed to analyze the imaging findings associated with L. monocytogenes rhombencephalitis in a cohort of patients with listeriosis.
We conducted a retrospective observational study of all declared cases of listeriosis in a tertiary hospital from Granada, Spain, from 2008 to 2021. Risk factors, comorbidities, and clinical outcomes were collected for all patients. In addition, clinical symptoms and magnetic resonance imaging (MRI) findings were included for those patients who developed rhombencephalitis. Descriptive and bivariate analyses were performed using SPSS statistical software (IBM SPSS, version 21).
Our cohort comprised 120 patients with listeriosis (41.7% women, mean age: 58.6 ± 23.8 years), of which 10 (8.3%) had rhombencephalitis. The most frequent MRI findings in patients with confirmed rhombencephalitis were T2-FLAIR hyperintensity (100%), T1 hypointensity (80%), scattered parenchymal enhancement (80%), and cranial nerve enhancement (70%), while the most frequent anatomical involvement were pons, medulla oblongata, and cerebellum. Complications occurred in 6 patients (abscess in 4, hemorrhage in 2, hydrocephalus in 1).
Rhombencephalitis is associated with an increased in-hospital mortality in patients with listeriosis. The anatomical distribution and imaging characteristics of neurolisteriosis could be useful to suggest the diagnosis. Future studies with greater sample size should explore the association between anatomical location, imaging patterns, and associated complications (e.g., hydrocephalus, hemorrhage), and clinical outcomes.
Epidemiología, clínica y resultados de imagen de rombencefalitis causada por L. monocytogenes. Un estudio observacional.
Introducción. Hasta la fecha, pocos estudios han explorado los factores de riesgo específicos de los pacientes con listeriosis que desarrollan rombencefalitis, y no hay suficiente información sobre los hallazgos de imagen y los síntomas clínicos en pacientes con esta enfermedad. El objetivo de este trabajo fue analizar los hallazgos de imagen asociados a la rombencefalitis por L. monocytogenes en una cohorte de pacientes con listeriosis. Materiales y métodos. Se realizó un estudio observacional retrospectivo de todos los casos declarados de listeriosis en un hospital terciario de Granada, España, desde 2008 hasta 2021. Se recogieron los factores de riesgo, las comorbilidades y los resultados clínicos de todos los pacientes. Además, se incluyeron los síntomas clínicos y los hallazgos de resonancia magnética (RM) de los pacientes que desarrollaron rombencefalitis. Se realizaron análisis descriptivos y bivariados utilizando el software estadístico SPSS (IBM SPSS, versión 21). Resultados. Nuestra cohorte incluyó a 120 pacientes con listeriosis (41,7%, mujeres; edad media: 58,6 ± 23,8 años), de los cuales 10 (8,3%) tenían rombencefalitis. Los hallazgos más frecuentes en la RM de los pacientes con rombencefalitis confirmada fueron hiperintensidad en T2-FLAIR (100%), hipointensidad en T1 (80%), realce parenquimatoso disperso (80%) y realce de los nervios craneales (70%), mientras que la afectación anatómica más frecuente fue en la protuberancia, la médula oblongada y el cerebelo. Se produjeron complicaciones en seis pacientes (absceso en cuatro, hemorragia en dos e hidrocefalia en uno). Conclusiones. La rombencefalitis se asocia a un aumento de la mortalidad intrahospitalaria en pacientes con listeriosis. La distribución anatómica y las características de imagen de la neurolisteriosis podrían ser útiles para sugerir el diagnóstico. Futuros estudios con mayor tamaño muestral deberían explorar la asociación entre la localización anatómica, los patrones de imagen y las complicaciones asociadas (por ejemplo, hidrocefalia y hemorragia), y los resultados clínicos.

Angiogenesis, the growth of new blood vessels from pre-existing ones, is a fundamental process for organ development, exercise-induced muscle growth, and wound healing, but is also associated with different diseases such as cancer and neovascular eye disease. Accordingly, elucidating the molecular and cellular mechanisms of angiogenesis has the potential to identify new therapeutic targets to stimulate new vessel formation in ischemic tissues or inhibit pathological vessel growth in disease. This chapter describes the mouse embryo hindbrain and postnatal retina as models to study physiological angiogenesis and provides detailed protocols for tissue dissection, sample staining and analysis.

Blood vessel growth is a fundamental process for organ development and wound healing but is also associated with ischemic diseases and cancer. The growth of new blood vessels from preexisting vasculature, termed sprouting angiogenesis, is the predominant mode of blood vessel growth in central nervous system vascularization and pathological vessel growth. Accordingly, studying the molecular and cellular mechanisms of angiogenesis holds the promise to find novel therapeutic targets to stimulate new vessel formation in ischemic tissues or inhibit pathological vessel growth in disease. The embryonic mouse hindbrain provides an excellent model to study sprouting angiogenesis in vivo by histochemical or fluorescent wholemount immunolabeling, thus allowing high-resolution image capture of nascent vasculature and subsequent quantification of relevant angiogenic parameters. This chapter describes how to use the mouse embryonic hindbrain as a model to study physiological angiogenesis, including detailed protocols for hindbrain dissection, wholemount staining, and angiogenic parameters analysis.

Toxoplasma gondii is an obligate intracellular parasite capable of invading any nucleated cell. Three main clonal lineages (type I, II, III) exist and murine models have driven the understanding of general and strain-specific immune mechanisms underlying Toxoplasma infection. However, murine models are limited for studying parasite-leukocyte interactions in vivo, and discrepancies exist between cellular immune responses observed in mouse versus human cells. Here, we developed a zebrafish infection model to study the innate immune response to Toxoplasma in vivo By infecting the zebrafish hindbrain ventricle, and using high-resolution microscopy techniques coupled with computer vision-driven automated image analysis, we reveal that Toxoplasma invades brain cells and replicates inside a parasitophorous vacuole to which type I and III parasites recruit host cell mitochondria. We also show that type II and III strains maintain a higher infectious burden than type I strains. To understand how parasites are cleared in vivo, we further analyzed Toxoplasma-macrophage interactions using time-lapse microscopy and three-dimensional correlative light and electron microscopy (3D CLEM). Time-lapse microscopy revealed that macrophages are recruited to the infection site and play a key role in Toxoplasma control. High-resolution 3D CLEM revealed parasitophorous vacuole breakage in brain cells and macrophages in vivo, suggesting that cell-intrinsic mechanisms may be used to destroy the intracellular niche of tachyzoites. Together, our results demonstrate in vivo control of Toxoplasma by macrophages, and highlight the possibility that zebrafish may be further exploited as a novel model system for discoveries within the field of parasite immunity.This article has an associated First Person interview with the first author of the paper.

Goal-directed behavior requires the interaction of multiple brain regions. How these regions and their interactions with brain-wide activity drive action selection is less understood. We have investigated this question by combining whole-brain volumetric calcium imaging using light-field microscopy and an operant-conditioning task in larval zebrafish. We find global, recurring dynamics of brain states to exhibit pre-motor bifurcations toward mutually exclusive decision outcomes. These dynamics arise from a distributed network displaying trial-by-trial functional connectivity changes, especially between cerebellum and habenula, which correlate with decision outcome. Within this network the cerebellum shows particularly strong and predictive pre-motor activity (>10 s before movement initiation), mainly within the granule cells. Turn directions are determined by the difference neuroactivity between the ipsilateral and contralateral hemispheres, while the rate of bi-hemispheric population ramping quantitatively predicts decision time on the trial-by-trial level. Our results highlight a cognitive role of the cerebellum and its importance in motor planning.

Neurovascular conflict (NVC) has been postulated to be the underlying cause of trigeminal neuralgia (TN). Does the posterior fossa crowdedness increase the chance of NVC? The aim of this study was to quantitatively measure the posterior fossa crowdedness in patients with TN and to perform a comparison with healthy controls. We conducted a prospective case-control study of 46 patients diagnosed with primary TN and 46 sex- and age-matched healthy controls. All subjects underwent high-resolution three-dimensional MRI, and the 3D Slicer software was used to measure the posterior fossa volume (PFV) and hindbrain volume (HBV). The posterior fossa crowdedness index (PFCI) was calculated as HBV/PFV × 100%. The results showed that patients with TN had a larger HBV (155.4 ± 23.2 cm3 versus 152.9 ± 13.5 cm3, P = .16) and a smaller PFV (182.7 ± 18.3 cm3 versus 186.1 ± 11.7 cm3, P = .42) as compared to control subjects, but these values were not significantly different. The mean PFCI was significantly higher in patients with TN than in controls (85.1% ± 3.4% versus 82.2% ± 5.3%; P = .03). Women had a more crowded posterior fossa than men (85.8% ± 2.1% versus 84.1% ± 2.6%; P = .023) in patients with TN. The correlation analysis showed that a higher PFCI was associated with younger age (P = .02), woman (P = .014), and TN disease (P = .001). From this study, we conclude that patients with TN have a more crowded posterior fossa than healthy subjects. Women, younger age and TN disease are associated with a higher PFCI. The posterior fossa crowdedness may be a risk factor of NVC, and thus more likely to result in the genesis of TN.

OBJECTIVE: Type I Chiari malformation (CMI) is a radiologically-defined structural dysmorphism of the hindbrain and posterior cranial fossa (PCF). Traditional radiographic identification of CMI relies on the measurement of the cerebellar tonsils in relation to the foramen magnum with or without associated abnormalities of the neuraxis. The primary goal of this retrospective study was to comprehensively assess morphometric parameters above the McRea line in a group of female CMI patients and normal controls.
METHODS: Twenty-nine morphological measurements were taken on 302 mid-sagittal MR images of adult female CMI patients (n=162) and healthy controls (n=140). All MR images were voluntarily provided by CMI subjects through an online database and control participant images were obtained through the Human Connectome Project and a local hospital system.
RESULTS: Analyses were performed on the full dataset of adult female MR images and a restricted dataset of 229 participants that were equated for age, race, and body mass index. Eighteen group differences were identified in the PCF area that we grouped into three clusters; PCF structures heights, clivus angulation, and odontoid process irregularity. Fourteen group differences persisted after equating our CMI and control groups on demographic characteristics.
CONCLUSIONS: PCF structures reliably differ in adult female CMI patients relative to healthy controls. These differences reflect structural abnormalities in the osseous and soft tissue structures of the clivus, odontoid process, and cerebellum. Clinical and pathophysiological implications are discussed.

BACKGROUND: Fetal cerebral ventricular dilatation (CVD) is a common abnormal prenatal finding that often predicts a poor prognosis. The etiology involves both genetic and nongenetic factors with diverse pathogenic mechanisms. We describe the neuropathological features of CVD in a large cohort of fetuses. The goals are to determine the physiopathological mechanisms and etiologies.
METHODS: We retrospectively analyzed a series of 130 fetuses examined at the Necker University Hospital following termination of pregnancy between January 2000 and December 2014. Chiari II and Dandy-Walker malformations were excluded from our study population. Karyotype and/or array comparative genomic hybridization were performed in all cases. Targeted Sanger sequencing or next generation sequencing were carried out in 34 and 5 cases, respectively.
RESULTS: We distinguished four groups of pathological entities: (1) midbrain/hindbrain patterning defects (54 cases, 42%), mainly related to aqueduct of Sylvius anomalies (atresia or stenosis); (2) cerebral cytoarchitectonic disorders (16 cases, 12%), essentially resulting from arachnoidal neuroglial ectopia; (3) hemorrhagic and perfusion failure (42 cases, 32%); and (4) nonspecific CVD (18 cases, 14%), without apparent obstruction, cortical malformation, or clastic injury. Although the pathogenic mechanisms of CVD were identified in 86% of cases, the causes, both acquired and genetic, were recognized in 21% of cases only.
CONCLUSIONS: The neuropathological analysis is a powerful tool in the diagnosis of the fetal CVD pathogenic mechanisms and to identify homogeneous groups. The paucity of molecular diagnosis, notably in the major groups of midbrain/hindbrain patterning defects and hemorrhagic and perfusion failure, highlights the needs of future research to improve our current knowledge on CVD causes. Birth Defects Research 109:1586-1595, 2017. © 2017 Wiley Periodicals, Inc.

The hindbrain develops through a process of segmentation which is coupled with the ordered expression of Hox genes to generate regional diversity of key neural and craniofacial derivatives during head development. This is a fundamental feature governed by a gene regulatory network conserved to the base of vertebrate evolution.