mouse inner ear extraction and stria vascularis dissection

Stria Vascularis Microdissection for Single-Nucleus Sequencing or Immunostaining

The cochlea consists of three fluid filled chambers, the scala vestibuli, scala media, and scala tympani. The scala vestibuli and scala tympani each contain perilymph, which has a high concentration of sodium (138 mM) and a low concentration of potassium (6.8 mM)1. The scala media contains endolymph, which has a high concentration of potassium (154 mM) and a low concentration of sodium (0.91 mM)1,2,3. This difference in ion concentration can be referred to as the endocochlear potential (EP), and is primarily generated by the movement of potassium ions through various ion channels and gap junctions in the stria vascularis (SV) along the lateral wall of the cochlea4,5,6,7,8,9,10,11. The SV is a heterogenous, highly vascularized tissue that lines the medial aspect of the lateral wall of the cochlea and contains three main cell types: marginal, intermediate, and basal cells12 (Figure 1).
Marginal cells are connected by tight junctions to form the most medial surface of the SV. The apical membrane faces the endolymph of the scala media and contributes to potassium ion transport into the endolymph using various channels, including KCNE1/KCNQ1, SLC12A2, and Na+-K+-ATPase (NKA)5,10,13,14. Intermediate cells are pigmented cells that reside between marginal and basal cells and facilitate potassium transport through the SV using KCNJ10 (Kir 4.1)15,16. Basal cells lie in close proximity to the lateral wall of the cochlea and are closely associated with fibrocytes of the spiral ligament to promote potassium recycling from the perilymph12. Pathology of the SV has been implicated in numerous otologic disorders17,18. Mutations in genes expressed in the major SV cell types, such as Kcnq1, Kcne1, Kcnj10, and Cldn11, can cause deafness and SV dysfunction, including the loss of EP19,20,21,22,23. In addition to the three major cell types, there are other less-studied cell types in the SV, such as spindle cells22, root cells12,24, macrophages25, pericytes26, and endothelial cells27, that have incompletely defined roles involving ionic homeostasis and the generation of EP28.
In comparison to bulk RNA-sequencing, single-nuclei RNA-sequencing (sNuc-Seq) provides information about cell heterogeneity, rather than an average of mRNA across a group of cells29, and can be particularly useful when studying the heterogenous SV30. For example, sNuc-Seq has produced transcriptional analysis that suggests there may be a role for spindle and root cells in EP generation, hearing loss, and Meniere&#39;s disease18. Further transcriptional characterization of the various SV cell types can provide us with invaluable information on the pathophysiology underlying different mechanisms and subtypes of SV-related hearing fluctuation and hearing loss. The harvest of these delicate inner ear structures is of paramount importance to optimal tissue analysis.
In this study, the microdissection approach to access and isolate the stria vascularis from the adult mouse cochlea for sNuc-Seq or immunostaining is described. Dissection of the adult mouse SV is required to understand various SV cell types and further characterize their role in hearing.

Author Spotlight: Dissection of Adult Mouse Stria Vascularis for Single-Nucleus Sequencing or Immunostaining  

Dissection of Adult Mouse Stria Vascularis for Single-Nucleus Sequencing or Immunostaining

The stria vascularis functions to generate the endocochlear potential and regulate ion homeostasis in the cochlea. The auditory development and restoration program seeks to understand the underlying mechanisms connecting dysfunctional ion homeostasis with hearing and stability disorders, which are diseases where either fluctuation in or sudden hearing loss occurs. Work in my lab has established the transcriptional landscape of the stria vascularis and has contributed to our understanding of its importance in hearing.We have used these data to draw parallels to poorly-understood hearing and stability disorders, including Meniere's disease. This protocol enables the dissection and isolation of whole-mount stria vascularis for further molecular studies including immunohistochemistry. Given that stria vascularis cell types are intricately intertwined with one another, the use of nuclear isolation and single-nucleus RNA sequencing has facilitated our understanding of the distinct transcriptional machinery involved.

Watch this Scientific Journal Video about Mouse Inner Ear Extraction and Stria Vascularis Dissection at JoVE.com

Mouse Inner Ear Extraction and Stria Vascularis Dissection  

To begin, identify the inner ear within the temporal bone of a euthanized mouse. Scrape away the cranial nerves using number 55 forceps. Then use number 55 forceps to dissect out the bulla and capsule, detaching them from surrounding bone.Remove any remaining soft tissue from the inner ear surface. For SV dissection, use number 55 forceps to hold the specimen by the vestibular portion with the cochlear facing up. Pierce through the cochlear bone at the apex using the same forceps.Scrape along the apical turn, applying gentle force to break away small pieces of the outer bone layer. Gently lift the bone and detach it from the lateral wall. Using number 55 forceps remove cochlear bone pieces from the apical and middle turns.Gently pushing down the lateral wall, pry and remove the bone wall pieces towards the middle turn to expose the lateral wall of the apical and middle turns. Push the apical turn lateral wall aside to expose the spiral ganglion. Detach the lateral wall of the apical and middle turns from the spiral ganglion along the outer hair cell layer.Then remove pieces of spiral ganglion from inside the cochlear. Detach the cochlear from the vestibular portion of the temporal bone by inserting the forceps into the round and oval window and pushing down towards the vestibule to have better access to the lateral wall of the basal turn. After the cochlear is detached remove the vestibular portion of the inner ear.Prioritize preserving as much of the strayer as possible. Continue removing til the bone of the middle turn is detached from the SV.Next, remove pieces of the remaining cochlear bone covering the basal turn. This can be accomplished by pushing the lateral wall layer under the bone to detach it.Pry and gently pull the tissue to remove the farthest basal part of the lateral wall being careful not to damage the soft tissue below. With the basal part of the lateral wall detached, separate the lateral wall from the remaining cochlear by tracing the forceps along the lateral wall. Gently brush the forceps between the bone and the remaining lateral wall until it reaches the apex.Then move the lateral wall to a fresh PBS. Lay the lateral wall flat revealing the SV as a darker layer of tissue on the internal side of the lateral wall. Gently pry the SV layer away from the lateral wall.Push aside the detached SV and advance the forceps along the lateral wall attempting to detach the SV as one long ribbon, trying not to squeeze the SV.Use a tissue scoop to collect the fragile tissue. Cochlear were dissected from adult mouse aged greater than or equal to postnatal day 30. Inner ear was extracted from the surrounding temporal bone.SV was exposed after the removal of bone covering the middle turn. The SV was fully separated from the lateral wall after dissection.

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520 ビュー.  National Institutes of Health. まず、安楽死させたマウスの側頭骨内の内耳を特定します。55番の鉗子を使って脳神経を削り取ります。次に、55番の鉗子を使用してブラとカプセルを解剖し、周囲の骨から外します。内耳の表面から残っている軟部組織を取り除きます。SV解剖の場合は、55番の鉗子を使用して、蝸牛を上に向けて前庭部で標本を保持します。同じ鉗子を使用して、頂点の蝸牛骨を?...

ビデオ: Mouse Inner Ear Extraction and Stria Vascularis Dissection  

dissection of adult mouse stria vascularis for single-nucleus sequencing or immunostaining

The stria vascularis is vital to the generation of endocochlear potential. Here, we present the dissection of the adult mouse stria vascularis for single-nucleus sequencing or...

immunostaining of mouse stria vascularis and tissue mounting

Immunostaining of Mouse Stria Vascularis and Tissue Mounting  

preparation of stria vascularis single-nucleus suspension

Preparation of Stria Vascularis Single-Nucleus Suspension  

gross and fine dissection of inner ear sensory epithelia in adult zebrafish (danio rerio)

Gross and Fine Dissection of Inner Ear Sensory Epithelia in Adult Zebrafish Danio rerio

The inner ear sensory epithelium of adult zebrafish is a good model system for understanding the mechanisms of hair cell regeneration in adult vertebrates. This protocol demonstrates the fine dissection of the epithelia, through which we can get tissue samples for studying the regenerative events at cellular and subcellular...

Gross and Fine Dissection of Inner Ear Sensory Epithelia in Adult Zebrafish (Danio rerio)

isolating vestibular ganglion neurons from a mouse inner ear

This video showcases a method for isolating vestibular neurons from a mouse pup&#39;s inner ear. It meticulously outlines the steps involved in dissecting the inner ear, harvesting the vestibular ganglion, and subsequently dissociating the ganglion into single cells. These cells are then cultured on glass-bottom dishes to establish a vestibular neuron...

Isolating Vestibular Ganglion Neurons From a Mouse Inner Ear

gene transfer to the developing mouse inner ear by in vivo electroporation

Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation

The mouse inner ear is a placode-derived sensory organ whose developmental program is elaborated during gestation. We define an in utero gene transfer technique consisting of three steps: mouse ventral laparotomy, transuterine microinjection, and in vivo electroporation. We use digital video microscopy to demonstrate the critical experimental embryological...

Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation

Remove the excess tissue from the back of the head and neck, to make the dissection area and otic capsule, cleaner and easier to access. Transfer the tissue to a second Petri dish with fresh L-15 solution. Then, locate the otic capsule and the auditory, superior vestibular, and inferior vestibular nerves. Separate the superior and inferior ganglia using small spring scissors, and cut away the auditory...

a protocol for decellularizing mouse cochleae for inner ear tissue engineering

A Protocol for Decellularizing Mouse Cochleae for Inner Ear Tissue Engineering

The goal of this protocol is to demonstrate an effective method to decellularize and decalcify mouse cochleae for utilization as scaffolds for tissue engineering...

isolating lacz-expressing cells from mouse inner ear tissues using flow cytometry

Isolating LacZ-expressing Cells from Mouse Inner Ear Tissues using Flow Cytometry

Flow cytometry is a powerful tool allowing for the isolation and study of specific cell populations. This protocol describes steps for isolating LacZ-expressing cells from cochlear tissues from neonatal transgenic mice. Dissociated cochlear cells were labeled using fluorescent-conjugated substrates of &#946;-galactosidase prior to separation via flow...

posterior semicircular canal approach for inner ear gene delivery in neonatal mouse

Posterior Semicircular Canal Approach for Inner Ear Gene Delivery in Neonatal Mouse

In this study, we describe the posterior semicircular canal approach as a reliable method for inner ear gene delivery in neonatal mice. We show that gene delivery through the posterior semicircular canal is able to perfuse the entire inner...

canalostomy for local drug delivery into the inner ear of an adult mouse

This video showcases canalostomy, a procedure that allows local drug delivery into the inner ear of a mouse through the semicircular canal with minimal damage to hearing and vestibular function. This method enables the inoculation of viral vectors, pharmaceuticals, and small molecules into the mouse&#39;s inner...

Canalostomy for Local Drug Delivery into the Inner Ear of an Adult Mouse

Next place, the animal in the right lateral position to facilitate surgery on the left ear. Make a one to 1.5-centimeter postauricular incision, three millimeters from the left retroauricular groove. Note, when the root of the pinna is defined as the origin, and the plane parallel to the calvarium as 3 to 9 o&#39;clock, the posterior semicircular canal and the lateral semicircular canal are typically located about three millimeters from the root of the pinna between 2 and 3...

discovering middle ear anatomy by transcanal endoscopic ear surgery: a dissection manual

Discovering Middle Ear Anatomy by Transcanal Endoscopic Ear Surgery: A Dissection Manual

The aim of this article is to describe the methodology of exclusively endoscopic cadaveric middle ear dissection. Moreover, we aim to provide a comprehensive guide to endoscopic middle ear...

in ovo and ex ovo methods to study avian inner ear development

In Ovo and Ex Ovo Methods to Study Avian Inner Ear Development

The chick is a cost-effective, accessible, and widely available model organism for a variety of studies. Here, a series of protocols is detailed to understand the molecular mechanisms underlying avian inner ear development and regeneration.

In Ovo and Ex Ovo Methods to Study Avian Inner Ear Development

patch clamp recordings in inner ear hair cells isolated from zebrafish

Patch Clamp Recordings in Inner Ear Hair Cells Isolated from Zebrafish

The purpose of this video is to demonstrate procedures for obtaining healthy, intact hair cells from the inner ear organs of adult zebrafish and then using them for patch clamp studies aimed at characterizing the biophysical properties of their voltage-gated...

perforated patch-clamp recordings of inner ear sensory neuron cell bodies

Lower the pipette into the bath of the recording chamber, and locate the pipette tip in the middle of the field of view. Ensure that the tip is free of air bubbles or other debris. Position the pipette close to the membrane, and land firmly on the center of the cell. Apply negative pressure or suction using a syringe or mouth...

Perforated Patch-Clamp Recordings of Inner Ear Sensory Neuron Cell Bodies

an integrated (microscopic/endoscopic) dissection ear surgery course

An Integrated Microscopic/Endoscopic Dissection Ear Surgery Course

Traditionally, otologic surgical training consisted of microscopic cadaveric dissections. However, during the last decades the endoscope has significantly ...

An Integrated (Microscopic/Endoscopic) Dissection Ear Surgery Course

Endocochlear potential, which is generated by the stria vascularis, is essential to maintain an environment conducive to appropriate hair cell mechanotransduction and ultimately hearing. Pathologies of the stria vascularis can result in a decreased hearing. Dissection of the adult stria vascularis allows for focused single-nucleus capture and subsequent single-nucleus sequencing and immunostaining. These techniques are used to study stria vascularis pathophysiology at the single-cell level. 
Single-nucleus sequencing can be used in the setting of transcriptional analysis of the stria vascularis. Meanwhile, immunostaining continues to be useful in identifying specific populations of cells. Both methods require proper stria vascularis dissection as a prerequisite, which can prove to be technically challenging.

The stria vascularis is vital to the generation of endocochlear potential. Here, we present the dissection of the adult mouse stria vascularis for single-nucleus sequencing or immunostaining.

Endocochlear potential, which is generated by the stria vascularis, is essential to maintain an environment conducive to appropriate hair cell ...

Homogenize the dissected stria vascularis tissue from mouse ear in a two-milliliter Dounce homogenizer, with 10 to 20 strokes on ice. Lyse the tissue on ice for 25 minutes. Then, filter the tissue through a 30-micron filter and spin the filtrate at 500G for five minutes at four degrees Celsius.Remove the supernatant and resuspend the cell pellet in one milliliter of nuclei wash and resuspension buffer. Next, filter the cells through a 10-micron filter and centrifuge at 500G for five minutes at four degrees Celsius. Remove the supernatant and resuspend in 50 microliters of nuclei wash and resuspension buffer.After Trypan Blue staining, dilute five microliters of the cell suspension into 50 microliters of 1X PBS and count the cells. To prepare single nuclei captures, load the sample with the desired nuclear density onto the chip.

Prepare for immunostaining by dissecting the stria vascularis from the mouse and add the tissue to a 24-well plate containing 200 microliters of 4%paraformaldehyde in 1X PBS. Incubate the tissue for 20 minutes at room temperature. perform two short washes of 1X PBS on an orbital shaker at low RPM.Remove the PBS, then perform permeabilization and blocking for a minimum of one hour at room temperature in 300 microliters of PBST solution. Next, stain the tissue with the primary antibody overnight at four degrees Celsius. Then add a secondary antibody and incubate for two hours at room temperature on an orbital shaker at low RPM.Cover the plate to protect the fluorescently tagged secondary antibody from light. Next, prepare a larger microslide by placing two small streaks of glue along the 25 mm axis, just smaller than the 18 by 18 millimeter glass cover slip. Place one drop of mounting reagent between the glue streaks.Using number 55 forceps, gab as little tissue as possible on one end of the SV, and transfer it from PBS to the mounting reagent. Place one end of the cover slip on the slide where one streak of glue was placed. Then gently release the cover slip to avoid creating air bubbles.Seal the mount by dabbing a drop of transparent nail polish on each corner of the mount. Label the specimen on the glass cover slip, away from the visualization field. Visualize the SV tissue under a dissection microscope to ensure it is lying flat and not near any air bubbles.If the SV tissue is not oriented correctly, try to push out air bubbles or carefully remove the smaller glass cover slip and reposition the SV.A whole mount of SV from P30 mouse was prepared and confocal imaging was performed. ZsGreen expression was observed in the intermediate cells, GSIB4 labeled endothelial cells, and DAPI labeled the nuclei.