Name: monocular visual deprivation and ocular dominance plasticity measurement in the mouse primary visual cortex
Uploaded: 2020-02-08T15:00:00
Description: Watch this Scientific Journal Video about Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex at JoVE.com

This study was supported by the National Natural Science Foundation of China (81571770, 81771925, 81861128001).

In this protocol, male C57Bl/6 mice were obtained from the Institute of Laboratory Animals of Sichuan Academy of Medical Sciences and Sichuan Provincial People&#39;s Hospital. All animal care and experimental procedures were approved by the Institutional Animal Care and Use Committee, University of Electronic Science and Technology of China.
1. Monocular deprivation (MD) at postnatal day 28 in mice
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	<li>Put the surgical tools, the suture needle (0.25 mm diameter, string diameter 0.07 mm...

<ol>
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We present a detailed protocol for MD and measuring OD plasticity by single unit recording. This protocol is widely used in visual neuroscience. Although the MD protocol is not complicated, there are some critical surgical procedures that must be followed carefully. First, there are two important details ensuring the quality of the stitching. The suture is sufficiently stable if the stitches are concentrated in the medial portion of the eyelid. Moreover, 3 &#956;L of glue is applied to the head of the knot to increase th...

Monocular visual deprivation is an excellent experimental paradigm to examine V1 plasticity. To study the importance of visual experience in neural development, David Hubel and Torsten Wiesel1,2 deprived kittens of normal vision in one eye at various time points and for varying periods of time. They then observed the changes in response intensity in V1 for the deprived and nondeprived eyes. Their results showed an abnormally low number of neurons reacting to the eye that had been sutured shut in the first three months. However, the responses from the neurons in the kittens remained identical in all respects to those of a normal adult cat&#39;s eye that was sutured shut for a year, and the kittens did not recover. MD in adult cats cannot induce OD plasticity. Therefore, the impact of visual experience on V1 wiring is strong during a brief, well-defined phase of development, before and after which the same stimuli have less influence. Such a phase of increased susceptibility to visual input is known as the critical period in visual cortex.
Although the mouse is a nocturnal animal, individual neurons in mouse V1 have similar properties to neurons found in cats3,4,5. In recent years, with the rapid development of transgenic technology, an increasing number of studies in visual neuroscience have used mice as an experimental model6,7,8. In mouse visual studies, neuroscientists use mutants and knockout mouse lines, which allow control over the genetic makeup of the mice. Although mice V1 lack OD columns, single neurons in the V1 binocular zone show significant OD properties. For example, most cells respond more strongly to contralateral stimulation than to ipsilateral stimulation. Temporary closure of one eye during the critical period induces a significant shift in the OD index distribution9,10,11. Therefore, MD can be used to establish an OD plasticity model to investigate how genes involved in neural developmental disorders influence cortical plasticity in vivo.
Here, we introduce an experimental method for MD and suggest a commonly used method (electrophysiological recording) to analyze the change in OD plasticity during monocular visual deprivation. The method has been widely used in many laboratories for more than 20 years12,13,14,15,16. There are other methods used in measuring the OD plasticity as well, such as chronic visual evoked potential (VEP) recording17, and intrinsic optical imaging (IOI)18. The significant advantage of this acute method is that it is easy to follow, and the results are remarkably reliable.

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monocular visual deprivation and ocular dominance plasticity measurement in the mouse primary visual cortex

Monocular visual deprivation is an excellent experimental paradigm to induce primary visual cortical response plasticity. In general, the response of the cortex to the contralateral eye to a stimulus is much stronger than the response of the ipsilateral eye in the binocular segment of the mouse primary visual cortex (V1). During the mammalian critical period, suturing the contralateral eye will result in a rapid loss of responsiveness of V1 cells to contralateral eye stimulation. With the continuing development of transgenic technologies, more and more studies are using transgenic mice as experimental models to examine the effects of specific genes on ocular dominance (OD) plasticity. In this study, we introduce detailed protocols for monocular visual deprivation and calculate the change in OD plasticity in mouse V1. After monocular deprivation (MD) for 4 days during the critical period, the orientation tuning curves of each neuron are measured, and the tuning curves of layer four neurons in V1 are compared between stimulation of the ipsilateral and contralateral eyes. The contralateral bias index (CBI) can be calculated using each cell&#39;s ocular OD score to indicate the degree of OD plasticity. This experimental technique is important for studying the neural mechanisms of OD plasticity during the critical period and for surveying the roles of specific genes in neural development. The major limitation is that the acute study cannot investigate the change in neural plasticity of the same mouse at a different time.

The experimental results described here enable successful MD and OD plasticity measurements from a deprived and nondeprived mouse during the critical period (P19&#8211;P32). Figure 1 shows how to perform single unit recordings in layer 4 from V1 the binocular zone for comparing responses in the ipsilateral and contralateral eye 4 days after MD. Figure 2 shows the spike sorting and orientation tuning measurements for stimulating the ipsilateral and contralateral ...

Watch this Scientific Journal Video about Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex at JoVE.com

Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex

Here, we present detailed protocols for monocular visual deprivation and ocular dominance plasticity analysis, which are important methods for studying the neural mechanisms of visual plasticity during the critical period and the effects of specific genes on visual development.

Monocular visual deprivation is an excellent experimental paradigm to induce primary visual cortical response plasticity. In general, the response of the ...

Monocular visual deprivation is an excellent experimental protocol to induce primary visual cortical response plasticity. Normally, neurons in the binocular segment of the primary visual cortex in the mouse respond about twice as strongly to the stimulation of the contralateral eye as to the ipsilateral eye. However, suturing shut the contralateral eye during the critical period for ocular dominance plasticity result in the rapid loss of responsiveness by the V1 neurons to the contralateral eye stimulation and also followed by a subsequent increase in the response to the ipsilateral eye.Here, we introduce the experimental protocol for monocular deprivation and to suggest a commonly used method to analyze the trend in ocular dominance during visual deprivation. Put the surgical tools in an aluminum box and autoclave them under 120 degrees Centigrade for half an hour. Prepare 2%agarose solution in water bath kettle and keep it at 75 degrees Centigrade.Apply a thin layer of eye ointment to both eyes. Under the anatomical microscope with illumination, suture the eyelids. Make about four stitches.Make two to three nodes of the thread. Apply three microliters of instant drying glue 502 on the head of the node to increase the stability of the node. Then cut the thread as short enough.When the mouse are fully awake, place them into a separated holding cage. Before electrophysiological recording, use isoflurane to anesthetize the mouse. Remove the stitches and expose the eyeball.Carefully trim the eyelid. Flush the eyes with contact lenses solutions and check the eyes for clarity. Only the mouse with good condition of the eyeballs can be used.After anesthetizing the mouse, place the mouse on a stereotaxic frame. Use a heating pad to maintain the body temperature throughout the procedure. Apply the eye ointment on the surface of the eyes to keep it moist.Remove the hair of the mouse to expose its skin. Incise an eight millimeters multiplied by eight millimeters area of skin between both ears to expose the skull and remove the scalp tissue. Then remove the overlying connective tissue with hydrogen peroxide.Drill a hole in the skull above the cerebellum. Fix a small bone screw in the hole as the reference. Perform a small craniotomy of one millimeter in diameter in V1 binocular region.Carefully remove the skull fragment without hurting the brain. Cover the exposed cortical surface with 2%agarose to prevent drying. Fix a tungsten electrode on the stereotaxic frame.Place the tungsten electrode vertically on binocular V1 region to make sure that the cells that are recorded reacts to both eyes. The stimulus is separated by 30 degrees in a random block. A total of three to five blocks were presented in each measurement.Mask one eye with nontransparent plastic plate. Present LCD1 to position in 23 centimeters from the mouse's eyes. Advance microelectrode slowly by the oil hydraulic micromanipulator.Stop advancement high signal noise ratio signal when the electrode is advanced to layer four and start measurement. We amplify spike activities at a factor of 1, 000 and filter it from 300 to 10 kilohertz and then sample it at 40 kilohertz. Then mask the other eye and measure the contralateral eye's response.Signals measured by single electrodes are population activities. Use software to separate spikes of different cells. First, filter the signal from 500 to 5, 000 hertz.Set two cursors, one for positive deflection and one for negative deflection spikes. Set up spike templates. Set the templates area where it shows the greatest variation between different classes of spikes.Use principal components analysis to separate them into clusters. Classify the spikes of a boundary by using the K means algorithm. Correlate the orientation with spike firing rate and plot the orientation tuning curves for the ipsilateral and contralateral eyes.Then calculate the OD index for single cells which represents the contralateral and ipsilateral response Assign an OD score for each cell according to the OD index. Calculate the contralateral bias index according to the formula. This diagram show the orientation tuning curves of the ipsilateral and contralateral eye in monocular deprived and nondeprived mouse.This protocol enables successful monocular visual deprivation and ocular dominance measurement from a deprived and a nondeprived mouse at critical period. We've just showed you how to accomplish this experiment and we had analyzed the change in ocular dominance during visual deprivation. During the experiment, it is important to avoid infection in the suturing process and interaction while electrophysiological recording.Thanks for watching our video.

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Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). We use an in vitro myelination assay, an established model for studying CNS myelination in vitro. To do this, oligodendrocyte precursor cells (OPCs) are added to the purified primary rodent dorsal root ganglion (DRG) neurons to form myelinating co-cultures. In order to specifically interrogate the roles that particular proteins expressed by oligodendrocytes exert upon myelination we have developed protocols that selectively transduce OPCs using the lentivirus overexpressing wild type, constitutively active or dominant negative proteins before being seeded onto the DRG neurons. This allows us to specifically interrogate the roles of these oligodendroglial proteins in regulating myelination. The protocols can also be applied in the study of other cell types, thus providing an approach that allows selective manipulation of proteins expressed by a desired cell type, such as oligodendrocytes for the targeted study of signaling and compensation mechanisms. In conclusion, combining the in vitro myelination assay with lentiviral infected OPCs provides a strategic tool for the analysis of molecular mechanisms involved in myelination.

Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays

Here we present protocols that offer a flexible and strategic foundation for virally manipulating oligodendrocyte precursor cells to overexpress proteins of interest in order to specifically interrogate their role in oligodendrocytes via the in vitro model of central nervous system myelination.

Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and ...

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Primary cells are derived directly from tissue and are thought to be more representative of the physiological state of cells in vivo than established cell lines. However, primary cell cultures usually have a finite life span and need to be frequently re-established. Fibroblasts are an easily accessible source of primary cells. Here, we discuss a simple and quick experimental procedure to establish primary fibroblast cultures from ears and tails of mice. The protocol can be used to establish primary fibroblast cultures from ears stored at RT for up to 10 days. When the protocol is carefully followed, contaminations are unlikely to occur despite the use of non-sterile tissue stored for extended time in some cases. Fibroblasts proliferate rapidly in culture and can be expanded to substantial numbers before undergoing replicative senescence.

We describe a simple and quick experimental procedure for generating primary fibroblasts from the ears and tails of mice. The procedure does not require special animal training and can be used for the generation of fibroblast cultures from ears stored at RT for up to 10 days.

Primary cells are derived directly from tissue and are thought to be more representative of the physiological state of cells in vivo than established cell ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Evaluation of Injury-induced Senescence and In Vivo Reprogramming in the Skeletal Muscle

Cellular senescence is a stress response that is characterized by a stable cellular growth arrest, which is important for many physiological and pathological processes, such as cancer and ageing. Recently, senescence has also been implicated in tissue repair and regeneration. Therefore, it has become increasingly critical to identify senescent cells in vivo. Senescence-associated &#946;-galactosidase (SA-&#946;-Gal) assay is the most widely used assay to detect senescent cells both in culture and in vivo. This assay is based on the increased lysosomal contents in the senescent cells, which allows the histochemical detection of lysosomal &#946;-galactosidase activity at suboptimum pH (6 or 5.5). In comparison with other assays, such as flow cytometry, this allows the identification of senescent cells in their resident environment, which offers valuable information such as the location relating to the tissue architecture, the morphology, and the possibility of coupling with other markers via immunohistochemistry&#160;(IHC). The major limitation of the SA-&#946;-Gal assay is the requirement of fresh or frozen samples.
Here, we present a detailed protocol to understand how cellular senescence promotes cellular plasticity and tissue regeneration in vivo. We use SA-&#946;-Gal to detect senescent cells in the skeletal muscle upon injury, which is a well-established system to study tissue regeneration. Moreover, we use&#160;IHC to detect Nanog, a marker of pluripotent stem cells, in a transgenic mouse model. This protocol enables us to examine and quantify cellular senescence in the context of induced cellular plasticity and in vivo reprogramming.

Evaluation of Injury-induced Senescence and In Vivo Reprogramming in the Skeletal Muscle

Here we present a detailed protocol to detect both senescent and pluripotent stem cells in the skeletal muscle upon injury while inducing in vivo reprogramming. This method is suitable for evaluating the role of cellular senescence during tissue regeneration and reprogramming in vivo.

Cellular senescence is a stress response that is characterized by a stable cellular growth arrest, which is important for many physiological and ...

A Novel Use of Three-dimensional High-frequency Ultrasonography for Early Pregnancy Characterization in the Mouse

High-frequency ultrasonography (HFUS) is a common method to non-invasively monitor the real-time development of the human fetus in utero. The mouse is routinely used as an in vivo model to study embryo implantation and pregnancy progression. Unfortunately, such murine studies require pregnancy interruption to enable follow-up phenotypic analysis. To address this issue, we used three-dimensional (3-D) reconstruction of HFUS imaging data for early detection and characterization of murine embryo implantation sites and their individual developmental progression in utero. Combining HFUS imaging with 3-D reconstruction and modeling, we were able to accurately quantify embryo implantation site number as well as monitor developmental progression in pregnant C57BL6J/129S mice from 5.5 days post coitus (d.p.c.) through to 9.5 d.p.c. with the use of a transducer. Measurements included: number, location, and volume of implantation sites as well as inter-implantation site spacing; embryo viability was assessed by cardiac activity monitoring. In the immediate post-implantation period (5.5 to 8.5 d.p.c.), 3-D reconstruction of the gravid uterus in both mesh and solid overlay format enabled visual representation of the developing pregnancies within each uterine horn. As genetically engineered mice continue to be used to characterize female reproductive phenotypes derived from uterine dysfunction, this method offers a new approach to detect, quantify, and characterize early implantation events in vivo. This novel use of 3-D HFUS imaging demonstrates the ability to successfully detect, visualize, and characterize embryo-implantation sites during early murine pregnancy in a non-invasive manner. The technology offers a significant improvement over current methods, which rely on the interruption of pregnancies for gross tissue and histopathologic characterization. Here we use a video and text format to describe how to successfully perform ultrasounds of early murine pregnancy to generate reliable and reproducible data with reconstruction of the uterine form in mesh and solid 3-D images.

Mice are widely used to study gestational biology. However, pregnancy termination is required for such studies which precludes longitudinal investigations and necessitates the use of large numbers of animals. Therefore, we describe a non-invasive technique of high-frequency ultrasonography for early detection and monitoring of post-implantation events in the pregnant mouse.

High-frequency ultrasonography (HFUS) is a common method to non-invasively monitor the real-time development of the human fetus in utero. The mouse is ...

Multi-Photon Time Lapse Imaging to Visualize Development in Real-time: Visualization of Migrating Neural Crest Cells in Zebrafish Embryos

Congenital eye and craniofacial anomalies reflect disruptions in the neural crest, a transient population of migratory stem cells that give rise to numerous cell types throughout the body. Understanding the biology of the neural crest has been limited, reflecting a lack of genetically tractable models that can be studied in vivo and in real-time. Zebrafish is a particularly important developmental model for studying migratory cell populations, such as the neural crest. To examine neural crest migration into the developing eye, a combination of the advanced optical techniques of laser scanning microscopy with long wavelength multi-photon fluorescence excitation was implemented to capture high-resolution, three-dimensional, real-time videos of the developing eye in transgenic zebrafish embryos, namely Tg(sox10:EGFP) and Tg(foxd3:GFP), as sox10 and foxd3 have been shown in numerous animal models to regulate early neural crest differentiation and likely represent markers for neural crest cells. Multi-photon time-lapse imaging was used to discern the behavior and migratory patterns of two neural crest cell populations contributing to early eye development. This protocol provides information for generating time-lapse videos during zebrafish neural crest migration, as an example, and can be further applied to visualize the early development of many structures in the zebrafish and other model organisms.

A combination of the advanced optical techniques of laser scanning microscopy with long wavelength multi-photon fluorescence excitation was implemented to capture high-resolution, three-dimensional, real-time imaging of neural crest migration in Tg(sox10:EGFP) and Tg(foxd3:GFP) zebrafish embryos.

Congenital eye and craniofacial anomalies reflect disruptions in the neural crest, a transient population of migratory stem cells that give rise to ...

Culturing of Retinal Pigment Epithelial Cells on an Ex Vivo Model of Aged Human Bruch's Membrane

Aside from vitamins and antioxidants recommended by the Age-Related Eye Disease Study, there is no effective therapy for &#34;dry,&#34;&#160;or atrophic age-related macular degeneration (AMD) which represents 90% of the cases. Therapies are needed to slow or retard the development of geographic atrophy (GA), and understanding Bruch&#39;s membrane pathology is part of this process. Alterations in human Bruch&#39;s membrane precede the progression of AMD by contributing to the damage of retinal pigment epithelial (RPE) cells. Given the lack of sufficient animal models to study AMD, ex vivo models of aged human Bruch&#39;s membrane serve as a useful tool to study the behavior of RPE cells from immortalized and primary cell lines as well as RPE lines derived from induced pluripotent stem cells (iPSCs). Here, we present a detailed method that allows one to determine the effects of RPE cell behavior seeded on harvested human Bruch&#39;s membrane explants from human donors, including attachment, apoptosis and proliferation, ability to phagocytize photoreceptor outer segments, establishment of polarity, and gene expression. This assay provides an ex vivo model of aged Bruch&#39;s membrane to assess the functional characteristics of RPE cells when seeded on aged/compromised extracellular matrix.

Culturing of Retinal Pigment Epithelial Cells on an Ex Vivo Model of Aged Human Bruch's Membrane

The goal of this protocol is to demonstrate the culturing of retinal pigment epithelial (RPE) cells on aged and/or diseased human Bruch&#39;s membrane. This method is suitable to study RPE cell behavior on a compromised extracellular matrix.

Aside from vitamins and antioxidants recommended by the Age-Related Eye Disease Study, there is no effective therapy for &#34;dry,&#34;&#160;or atrophic ...

Induction and Validation of Cellular Senescence in Primary Human Cells

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a hallmark of various pathophysiological conditions including tumor suppression, tissue remodeling and aging. The inducers of cellular senescence in vivo are still poorly characterized. However, a number of stimuli can be used to promote cellular senescence ex vivo. Among them, most common senescence-inducers are replicative exhaustion, ionizing and non-ionizing radiation, genotoxic drugs, oxidative stress, and demethylating and acetylating agents. Here, we will provide detailed instructions on how to use these stimuli to induce fibroblasts into senescence. This protocol can easily be adapted for different types of primary cells and cell lines, including cancer cells. We also describe different methods for the validation of senescence induction. In particular, we focus on measuring the activity of the lysosomal enzyme Senescence-Associated &#946;-galactosidase (SA-&#946;-gal), the rate of DNA synthesis using 5-ethynyl-2&#39;-deoxyuridine (EdU) incorporation assay, the levels of expression of the cell cycle inhibitors p16 and p21, and the expression and secretion of members of the Senescence-Associated Secretory Phenotype (SASP). Finally, we provide example results and discuss further applications of these protocols.

Here, we discuss a series of protocols for induction and validation of cellular senescence in cultured cells. We focus on different senescence-inducing stimuli and describe the quantification of common senescence-associated markers. We provide technical details using fibroblasts as a model, but the protocols can be adapted to various cellular models.

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a ...

Visualizing the Node and Notochordal Plate In Gastrulating Mouse Embryos Using Scanning Electron Microscopy and Whole Mount Immunofluorescence

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is the formation of the transient organizers, the node and notochordal plate, from cells that have passed through the primitive streak. The proper formation of these signaling centers is essential for the development of the body plan and techniques to visualize them are of high interest to mouse developmental biologists. The node and notochordal plate lie on the ventral surface of gastrulating mouse embryos around embryonic day (E) 7.5 of development. The node is a cup-shaped structure whose cells possess a single slender cilium each. The proper subcellular localization and rotation of the cilia in the node pit determines left-right asymmetry. The notochordal plate cells also possess single cilia albeit shorter than those of the node cells. The notochordal plate forms the notochord which acts as an important signaling organizer for somitogenesis and neural patterning. Because the cells of the node and notochordal plate are transiently present on the surface and possess cilia, they can be visualized using scanning electron microscopy (SEM). Among other techniques used to visualize these structures at the cellular level is whole mount immunofluorescence (WMIF) using the antibodies against the proteins that are highly expressed in the node and notochordal plate. In this report, we describe our optimized protocols to perform SEM and WMIF of the node and notochordal plate in developing mouse embryos to help in the assessment of tissue shape and cellular organization in wild-type and gastrulation mutant embryos.

The node and notochordal plate are transient signaling organizers in developing mouse embryos that can be visualized using several techniques. Here, we describe in detail how to perform two of the techniques to study their structure and morphogenesis: 1) scanning electron microscopy (SEM); and 2) whole mount immunofluorescence (WMIF).

The post-implantation mouse embryo undergoes major shape changes after the initiation of gastrulation and morphogenesis. A hallmark of morphogenesis is ...

Visualization of the Superior Ocular Sulcus during Danio rerio Embryogenesis

Congenital ocular coloboma is a genetic disorder that is typically observed as a cleft in the inferior aspect of the eye resulting from incomplete choroid fissure closure. Recently, the identification of individuals with coloboma in the superior aspect of the iris, retina, and lens led to the discovery of a novel structure, referred to as the superior fissure or superior ocular sulcus (SOS), that is transiently present on the dorsal aspect of the optic cup during vertebrate eye development. Although this structure is conserved across mice, chick, fish, and newt, our current understanding of the SOS is limited. In order to elucidate factors that contribute to its formation and closure, it is imperative to be able to observe it and identify abnormalities, such as delay in the closure of the SOS. Here, we set out to create a standardized series of protocols that can be used to efficiently visualize the SOS by combining widely available microscopy techniques with common molecular biology techniques such as immunofluorescent staining and mRNA overexpression. While this set of protocols focuses on the ability to observe SOS closure delay, it is adaptable to the experimenter&#39;s needs and can be easily modified. Overall, we hope to create an approachable method through which our understanding of the SOS can be advanced to expand the current knowledge of vertebrate eye development.

Visualization of the Superior Ocular Sulcus during Danio rerio Embryogenesis

Here, we present a standardized series of protocols to observe the superior ocular sulcus, a recently-identified, evolutionarily-conserved structure in the vertebrate eye. Using zebrafish larvae, we demonstrate techniques necessary to identify factors that contribute to the formation and closure of the superior ocular sulcus.

Congenital ocular coloboma is a genetic disorder that is typically observed as a cleft in the inferior aspect of the eye resulting from incomplete choroid ...