scholarly journals Role of neuronal positioning in jaw motor circuit function in zebrafish

2021 ◽  
Author(s):  
◽  
Asante Emilia Boakyewaa
Keyword(s):  
Neuronal Migration ◽  
Neuromuscular Junctions ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Jaw Muscles ◽  
Jaw Movement ◽  
Facial Motor Nucleus ◽  
Circuit Function ◽  
Circuit Output ◽  
Functional Output

Development of the vertebrate nervous system involves substantial cell migration, where immature neurons move to specific locations to generate functional circuits. Precise neuronal migration and positioning are essential for proper brain architecture and function. Abnormal neuronal migration can contribute to neurological disorders such as lissencephaly, autism and schizophrenia. However, the consequences of abnormal neuronal migration for circuit organization and functional output are poorly understood. To provide some insight, I used the facial branchiomotor (FBM) neurons in zebrafish as a model system to analyze the effects of aberrant neuronal migration on circuit function. The FBM neurons are a subset of the branchiomotor neurons, which are generated in the vertebrate hindbrain and innervate facial and jaw muscles. During development in zebrafish and mice, FBM neurons migrate caudally from rhombomere 4 (r4) to r6 to form the facial motor nucleus and innervate jaw and gill muscles (in fish). In order to examine the consequences of aberrant neuronal migration, one must first characterize the normal functional output of the FBM circuit that drives jaw movements. In collaboration with colleagues in the MU Department of Computer Science, we developed an automated image analysis system to extract motion features from video recordings of jaw movement, enabling rapid and accurate high-throughput analysis. We used this software to examine the emergence of jaw movement in zebrafish larvae between 3-9 days post fertilization (dpf). While gape, the displacement of the lower jaw to form the mouth opening, was minimal at 3 dpf, gape frequency increased sharply by 5 dpf, and stabilized by 7 dpf. A detailed analysis of branchiomotor axons and neuromuscular junctions (NMJs) on jaw muscles suggest that this "maturation" of branchiomotor circuit output may be driven by changes in presynaptic structures at the jaw NMJs. To evaluate the consequences of defective neuronal migration on circuit output, I examined whether jaw movement was affected in the zebrafish off-limits (olt) mutant in which FBM neurons fail to migrate out of r4. In olt mutants, the increase in gape frequency occurred normally between 3-5 dpf. However, the average gape frequency was [approximately] 50 [percent] lower than wildtype siblings from 5-9 dpf while gape amplitude was unaffected. Given the jaw movement defect in olt mutants, I evaluated food intake, an independent measure of jaw movement and another functional output of the branchiomotor circuit. Olt mutants ate poorly compared to their wildtype siblings, consistent with their reduced jaw movement. I then tested several potential mechanisms that could generate the functional deficits in olt mutants. While fzd3a, the gene inactivated in olt mutants, is ubiquitously expressed in neural and non-neural tissues, jaw cartilage and muscle developed normally in olt mutants, and muscle function also appeared to be unaffected. Although FBM neurons were mispositioned in olt mutants, axon pathfinding to jaw muscles were unaffected. Moreover, neuromuscular junctions established by FBM neurons on jaw muscles were similar between wildtype siblings and olt mutants. Interestingly, FBM axons innervating the interhyoideus jaw muscle were frequently defasciculated in olt mutants. Furthermore, GCaMP imaging revealed that mutant FBM neurons were less active than their wildtype counterparts. These data suggest that aberrant positioning of FBM neurons in olt mutants results in subtle defects in fasciculation and neuronal activity, potentially generating defective functional outputs. In the future, we will examine modulatory inputs from other brain regions to the branchiomotor neurons and examine their roles in impacting circuit output in olt mutants.

scholarly journals Defective Neuronal Positioning Correlates With Aberrant Motor Circuit Function in Zebrafish

2021 ◽  
Vol 15 ◽  
Author(s):  
Emilia Asante ◽  
Devynn Hummel ◽  
Suman Gurung ◽  
Yasmin M. Kassim ◽  
Noor Al-Shakarji ◽  
...  
Keyword(s):  
Neuromuscular Junctions ◽  
Larval Feeding ◽  
Normal Brain ◽  
Axon Pathfinding ◽  
Loss Of Function ◽  
Jaw Muscles ◽  
Normal Brain Function ◽  
Functional Consequences ◽  
And Migration ◽  
Circuit Function

Precise positioning of neurons resulting from cell division and migration during development is critical for normal brain function. Disruption of neuronal migration can cause a myriad of neurological disorders. To investigate the functional consequences of defective neuronal positioning on circuit function, we studied a zebrafish frizzled3a (fzd3a) loss-of-function mutant off-limits (olt) where the facial branchiomotor (FBM) neurons fail to migrate out of their birthplace. A jaw movement assay, which measures the opening of the zebrafish jaw (gape), showed that the frequency of gape events, but not their amplitude, was decreased in olt mutants. Consistent with this, a larval feeding assay revealed decreased food intake in olt mutants, indicating that the FBM circuit in mutants generates defective functional outputs. We tested various mechanisms that could generate defective functional outputs in mutants. While fzd3a is ubiquitously expressed in neural and non-neural tissues, jaw cartilage and muscle developed normally in olt mutants, and muscle function also appeared to be unaffected. Although FBM neurons were mispositioned in olt mutants, axon pathfinding to jaw muscles was unaffected. Moreover, neuromuscular junctions established by FBM neurons on jaw muscles were similar between wildtype siblings and olt mutants. Interestingly, motor axons innervating the interhyoideus jaw muscle were frequently defasciculated in olt mutants. Furthermore, GCaMP imaging revealed that mutant FBM neurons were less active than their wildtype counterparts. These data show that aberrant positioning of FBM neurons in olt mutants is correlated with subtle defects in fasciculation and neuronal activity, potentially generating defective functional outputs.

scholarly journals Assessing Small Bowel Stricturing and Morphology in Crohn’s Disease Using Semi-automated Image Analysis

2019 ◽  
Vol 26 (5) ◽  
pp. 734-742 ◽  
Author(s):  
Ryan W Stidham ◽  
Binu Enchakalody ◽  
Akbar K Waljee ◽  
Peter D R Higgins ◽  
Stewart C Wang ◽  
...  
Keyword(s):  
Image Analysis ◽  
Crohn’S Disease ◽  
Small Bowel ◽  
Crohn's Disease ◽  
Structural Damage ◽  
Clinical Decision Making ◽  
Tertiary Care ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Ct Enterography

Abstract Background Evaluating structural damage using imaging is essential for the evaluation of small intestinal Crohn’s disease (CD), but it is limited by potential interobserver variation. We compared the agreement of enterography-based bowel damage measurements collected by experienced radiologists and a semi-automated image analysis system. Methods Patients with small bowel CD undergoing a CT-enterography (CTE) between 2011 and 2017 in a tertiary care setting were retrospectively reviewed. CT-enterography studies were reviewed by 2 experienced radiologists and separately underwent automated computer image analysis using bowel measurement software. Measurements included maximum bowel wall thickness (BWT-max), maximum bowel dilation (DIL-max), minimum lumen diameter (LUM-min), and the presence of a stricture. Measurement correlation coefficients and paired t tests were used to compare individual operator measurements. Multivariate regression was used to model identification of strictures using semi-automated measures. Results In 138 studies, the correlation between radiologists and semi-automated measures were similar for BWT-max (r = 0.724, 0.702), DIL-max (r = 0.812, 0.748), and LUM-min (r = 0.428, 0.381), respectively. Mean absolute measurement difference between semi-automated and radiologist measures were no different from the mean difference between paired radiologists for BWT-max (1.26 mm vs 1.12 mm, P = 0.857), DIL-max (2.78 mm vs 2.67 mm, P = 0.557), and LUM-min (0.54 mm vs 0.41 mm, P = 0.596). Finally, models of radiologist-defined intestinal strictures using automatically acquired measurements had an accuracy of 87.6%. Conclusion Structural bowel damage measurements collected by semi-automated approaches are comparable to those of experienced radiologists. Radiomic measures of CD will become an important new data source powering clinical decision-making, patient-phenotyping, and assisting radiologists in reporting objective measures of disease status.

scholarly journals A novel automated image analysis system using deep convolutional neural networks can assist to differentiate MDS and AA

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Konobu Kimura ◽  
Yoko Tabe ◽  
Tomohiko Ai ◽  
Ikki Takehara ◽  
Hiroshi Fukuda ◽  
...  
Keyword(s):  
Neural Networks ◽  
Blood Cell ◽  
Convolutional Neural Networks ◽  
Image Recognition ◽  
Diagnostic System ◽  
Learning System ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Cell Image ◽  
Extreme Gradient Boosting

Abstract Detection of dysmorphic cells in peripheral blood (PB) smears is essential in diagnostic screening of hematological diseases. Myelodysplastic syndromes (MDS) are hematopoietic neoplasms characterized by dysplastic and ineffective hematopoiesis, which diagnosis is mainly based on morphological findings of PB and bone marrow. We developed an automated diagnostic support system of MDS by combining an automated blood cell image-recognition system using a deep learning system (DLS) powered by convolutional neural networks (CNNs) with a decision-making system using extreme gradient boosting (XGBoost). The DLS of blood cell image-recognition has been trained using datasets consisting of 695,030 blood cell images taken from 3,261 PB smears including hematopoietic malignancies. The DLS simultaneously classified 17 blood cell types and 97 morphological features of such cells with >93.5% sensitivity and >96.0% specificity. The automated MDS diagnostic system successfully differentiated MDS from aplastic anemia (AA) with high accuracy; 96.2% of sensitivity and 100% of specificity (AUC 0.990). This is the first CNN-based automated initial diagnostic system for MDS using PB smears, which is applicable to develop new automated diagnostic systems for various hematological disorders.

Automated image analysis of Euglena gracilis Klebs (Euglenophyta) for measuring sublethal effects of three model contaminants

2012 ◽  
Vol 66 (8) ◽  
pp. 1708-1715 ◽  
Author(s):  
I. Netto ◽  
V. Bostan ◽  
L. McCarthy ◽  
A. Laursen ◽  
K. Gilbride ◽  
...  
Keyword(s):  
Image Analysis ◽  
Euglena Gracilis ◽  
Cell Shape ◽  
Early Warning Systems ◽  
Visual Observation ◽  
Automated Image Analysis ◽  
Swimming Velocity ◽  
Image Analysis System ◽  
Behavioural Changes ◽  
Analysis System

The short-term impacts of atrazine (herbicide), tributyltin (organometal) and copper on the behaviour of Euglena gracilis Klebs (Euglenophyta) were assessed. First, the ECOTOX automated image analysis system was used, which measured swimming velocity, cell shape, percentage of cells swimming upwards, and randomness of swimming. Next, visual observation by microscopy was used to measure percentage of cell motility and cell shape. Behavioural changes can be used as an indicator of stress in less than 24 h, potentially making them suitable for inclusion in early-warning systems for water quality. Findings indicate that E. gracilis is a very sensitive organism to copper, showing inhibition of motility with visual observation at 0.8 μmol/L within 1 h. The image analysis system was in general less sensitive than visual observation for detecting behavioural changes after incubation in copper. In contrast, after exposure to organic contaminants atrazine and tributyltin, the ECOTOX system detected small changes in the number of cells swimming upwards (antigravitactic behaviour) at higher concentrations.

The PD1/PD-L1 Axis in the Classical Hodgkin Lymphoma Microenvironment: PD-1 Is Rarely Expressed but Identifies Patients with High-Risk Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1560-1560
Author(s):  
Paul Greaves ◽  
Andrew James Clear ◽  
Andrew Owen ◽  
Andrew Wilson ◽  
Janet Matthews ◽  
...  
Keyword(s):  
Immune Response ◽  
Clinical Outcome ◽  
Hodgkin Lymphoma ◽  
Adverse Outcome ◽  
Germinal Centre ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Malignant Cells ◽  
Classical Hodgkin Lymphoma ◽  
Median Expression

Abstract Abstract 1560 Introduction: Classical Hodgkin lymphoma (CHL) is histologically unique: the malignant Hodgkin Reed-Sternberg cell (HRS) represents a fraction of tumour bulk, the majority being inflammatory cells: a combination of inadequate immune response and tumor-supportive microenvironment. PD-1 is a T-cell expressed CD28-analogue that inhibits activity of the expressing cell by interactions with ligands including the B7 analogue PD-L1. PD-L1 is upregulated in a range of immune and non-immune cells including malignant cells. Immunosuppression through this axis may contribute to failed immune response and adverse outcome in some tumors (Keir et al. Annu Rev Immunol, 2008; 26: 677–704) and there are reports regarding expression levels and pathway activity (Chemnitz et al. Blood, 2007; 110: 3226–33) as well as biological importance in CHL (Yamamoto et al. Blood, 2008; 111: 3220–3224). PD-L1 is overexpressed by HRS cells and encoded by a chromosomal region showing recurrent copy number gains in CHL (Steidl et al. Blood, 2010; 116: 418- 427). PD1/PD-L1 interactions are also essential to the survival of germinal centre B cells (Good-Jacobson et al. Nature Imm; 2010; 11: 535–42) the normal counterparts of the HRS, implying a potential direct supportive role for this pathway independent of the immune response. While the mechanistic importance of this axis in CHL is widely stated, little published evidence exists to substantiate it. This immunohistochemical (IHC) study set out to determine levels and variability of expression of PD-1 and PD-L1 at diagnosis in CHL and determine prognostic importance. Methods: IHC analysis was performed on tissue microarrays (TMAs) from 122 previously untreated CHL patients with known clinical outcome: median age 30 (range 18–80), 35% female, 71% advanced stage, median follow up 16.5 (range 2–40) years. Triplicate cores were made from areas of high cellularity avoiding fibrotic or acellular portions, arrayed and stained for PD-1 or PD-L1. Positive cells were counted across all cores using an automated image analysis system (Ariol), output confirmed by expert histopathologists, and means calculated corrected to % infiltration per 1mm2. 105 cases (86%) had tissue of sufficient quality for full IHC assessment. Groups were determined based on population distribution of infiltration levels and confirmed using the test/validation set method. Outcomes of freedom from first-line treatment failure (FFTF), disease-specific survival (DSS) and overall survival (OS) were assessed using the Kaplan Meier method with statistically significant differences between groups calculated using the log-rank test. Results: PD-1 expression was strikingly low or absent in the microenvironment of the majority of cases: <1% of cells in 40% of cases and <5% of cells in 80%. Median expression was 0.14% of all nucleated cells (range 0–8.9%). When present, this was predominantly as a low-level background infiltrate with frequent clusters/nodules of PD-1 positive lymphoid cells aggregating around HRS cells. Notably, the rare patients with high expression of PD-1 had adverse outcome. The 20% of patients with infiltration >0.5% cells had DSS 61% vs 89% at both 5 and 10 years (p=0.03). In contrast, PD-L1 was expressed at a high level in both HRS and the microenvironment in the majority of cases: >10% cells in 38% of cases, and <1% in only 5%. Median expression was 6.1% (range 0.2%–40%). Level of PD-L1 expression in the microenvironment was not associated with any measure of clinical outcome. Conclusions: PD-1 may have biological significance, as measured by impact on prognosis in a minority of patients with CHL, where overexpression is associated with an increased chance of CHL-related death. This may relate to immunosuppression, but the very low overall levels of expression and tendency to cluster around the malignant cells (a pattern seen more often in nodular lymphocyte predominant HL) imply a more localised HRS interactive role perhaps equivalent to the pathway's activity in a normal germinal centre. Its ligand PD-L1 is highly expressed in the microenvironment as well as in the HRS, which may relate to an activated rather than suppressive microenvironment, but without association with prognosis. We conclude that for the majority of patients with CHL, the definitive role for this pathway remains to be demonstrated conclusively. Disclosures: Gribben: Roche: Honoraria; Celgene: Honoraria; GSK: Honoraria; Mundipharma: Honoraria; Gilead: Honoraria; Pharmacyclics: Honoraria.

An automated image analysis system for major maceral group analysis in coals

Fuel ◽  
1994 ◽  
Vol 73 (11) ◽  
pp. 1729-1734 ◽  
Author(s):  
Edward Lester ◽  
Martin Allen ◽  
Michael Cloke ◽  
Nick J. Miles
Keyword(s):  
Image Analysis ◽  
Group Analysis ◽  
Automated Image Analysis ◽  
Image Analysis System ◽  
Analysis System
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