We thank Dr. Yuriy M. Usachev for his help in the initial standardization of confocal microscopy/imaging of mouse plantar punch biopsy immunostaining; and Dr. Donna L. Hammond for her continued help and constructive criticism in this work. This work was funded by grants from the NINDS/NIH (NS069898), and an Idea Development Grant Award from the Department of Defense Prostate Cancer Research Program (DoD-PCRP-101096) to D.P.M.

1. Animal Perfusion
All animal procedures performed in this study are approved by the Institutional Animal Care and Use Committee of the University of Iowa, and follow NIH guidelines for the use of animals in research.
<ol>
	<li>On the day before perfusion, prepare 1 L of phosphate buffer (0.2 M PB in double distilled H2O, pH 7.4), and store at 4&deg;C. This will be used for perfusion and post-fixation processes.</li>
	<li>On the day of perfusion, prepare 500 ml of 4.0% paraformal...

<ol>
	<li>Hoffman, E. M., Schechter, R., Miller, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fixative+Composition+Alters+Distributions+of+Immunoreactivity+for+Glutaminase+and+Two+Markers+of+Nociceptive+Neurons,+Nav+1.8+and+TRPV1,+in+the+Rat+Dorsal+Root+Ganglion.">Fixative Composition Alters Distributions of Immunoreactivity for Glutaminase and Two Markers of Nociceptive Neurons, Nav 1.8 and TRPV1, in the Rat Dorsal Root Ganglion.</a> Journal of Histochemistry &#38; Cytochemistry. 58, 329-344 (2010).</li><li>Neves, J. D. S., Omar, N. F., Narvaes, E. A. O., Gomes, J. R., Novaes, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+different+decalcifying+agents+on+EGF+and+EGFR+immunostaining.">Influence of different decalcifying agents on EGF and EGFR immunostaining.</a> Acta Histochemica. 113, 484-488 (2011).</li><li>Watson, R. E., Wiegand, S. J., Clough, R. W., Hoffman, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+cryoprotectant+to+maintain+long-term+peptide+immunoreactivity+and+tissue+morphology.">Use of cryoprotectant to maintain long-term peptide immunoreactivity and tissue morphology.</a> Peptides. 7, 155-159 (1986).</li><li>Yen, L. D., Bennett, G. J., Ribeiro-da-Silva, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sympathetic+sprouting+and+changes+in+nociceptive+sensory+innervation+in+the+glabrous+skin+of+the+rat+hind+paw+following+partial+peripheral+nerve+injury.">Sympathetic sprouting and changes in nociceptive sensory innervation in the glabrous skin of the rat hind paw following partial peripheral nerve injury.</a> The Journal of Comparative Neurology. 495, 679-690 (2006).</li><li>Boyette-Davis, J., Xin, W., Zhang, H., Dougherty, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraepidermal+nerve+fiber+loss+corresponds+to+the+development+of+Taxol-induced+hyperalgesia+and+can+be+prevented+by+treatment+with+minocycline.">Intraepidermal nerve fiber loss corresponds to the development of Taxol-induced hyperalgesia and can be prevented by treatment with minocycline.</a> Pain. 152, 308-313 (2011).</li><li>Bloom, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breast+Cancer-Induced+Bone+Remodeling,+Skeletal+Pain,+and+Sprouting+of+Sensory+Nerve+Fibers.">Breast Cancer-Induced Bone Remodeling, Skeletal Pain, and Sprouting of Sensory Nerve Fibers.</a> The Journal of Pain. 12, 698-711 (2011).</li><li>Constantin, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endogenous+Tumor+Necrosis+Factor+&#945;+(TNF&#945;)+Requires+TNF+Receptor+Type+2+to+Generate+Heat+Hyperalgesia+in+a+Mouse+Cancer+Model.">Endogenous Tumor Necrosis Factor &#945; (TNF&#945;) Requires TNF Receptor Type 2 to Generate Heat Hyperalgesia in a Mouse Cancer Model.</a> J. Neurosci. 28, 5072-5081 (2008).</li><li>Jankowski, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitization+of+Cutaneous+Nociceptors+after+Nerve+Transection+and+Regeneration:+Possible+Role+of+Target-Derived+Neurotrophic+Factor+Signaling.">Sensitization of Cutaneous Nociceptors after Nerve Transection and Regeneration: Possible Role of Target-Derived Neurotrophic Factor Signaling.</a> The Journal of Neuroscience. 29, 1636-1647 (2009).</li><li>Jimenez-Andrade, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathological+Sprouting+of+Adult+Nociceptors+in+Chronic+Prostate+Cancer-Induced+Bone+Pain.">Pathological Sprouting of Adult Nociceptors in Chronic Prostate Cancer-Induced Bone Pain.</a> J. Neurosci. 30, 14649-14656 (2010).</li><li>Persson, A. -. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sodium-calcium+exchanger+and+multiple+sodium+channel+isoforms+in+intra-epidermal+nerve+terminals.">Sodium-calcium exchanger and multiple sodium channel isoforms in intra-epidermal nerve terminals.</a> Molecular Pain. 6, 84-84 (2010).</li><li>Ohshima, M., Miyake, M., Takeda, M., Kamijima, M., Sakamoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Staphylococcal+Enterotoxin+B+Causes+Proliferation+of+Sensory+C-Fibers+and+Subsequent+Enhancement+of+Neurogenic+Inflammation+in+Rat+Skin.">Staphylococcal Enterotoxin B Causes Proliferation of Sensory C-Fibers and Subsequent Enhancement of Neurogenic Inflammation in Rat Skin.</a> Journal of Infectious Diseases. 203, 862-869 (2011).</li><li>Johnson, M. S., Ryals, J. M., Wright, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+loss+of+peptidergic+intraepidermal+nerve+fibers+in+an+STZ-induced+mouse+model+of+insensate+diabetic+neuropathy.">Early loss of peptidergic intraepidermal nerve fibers in an STZ-induced mouse model of insensate diabetic neuropathy.</a> Pain. 140, 35-47 (2008).</li></ol>

Here we have detailed the methods for preparation of mouse skin and bone tissue sections for immunostaining and detection of peripheral sensory nerve fibers. The sections produced from plantar punch biopsies contain both glabrous and hairy skin, which means the protocol can be used on any skin type. These techniques can also be employed to stain other cell types in these tissues (e.g. leukocytes, vascular endothelia, smooth muscle among others). These methods provide an excellent compromise between optimal ultrastructura...

<table border="1">
<tbody>
 <tr>
 <td>Material Name</td>
 <td>Type</td>
 <td>Company</td>
 <td>Catalogue No.</td>
 <td>Comment</td>
 </tr>
 <tr>
 <td>3mm 			Harris Micro-Punch</td>
 <td>Material</td>
 <td>Ted 			Pella</td>
 <td>15094</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Perfusion 			pump</td>
 <td>Material</td>
 <td>VWR 			International</td>
 <td>23609-170</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Paraformaldehyde</td>
 <td>Reagent</td>
 <td>Fisher 			Scientific</td>
 <td>T353</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Picric 			acid</td>
 <td>Reagent</td>
 <td>Sigma-Aldrich</td>
 <td>239801</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>OCT 			Embedding compound</td>
 <td>Reagent</td>
 <td>Tissue-Tek</td>
 <td>4583</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Cyto-Freeze 			cryogenic aerosol spray</td>
 <td>Material</td>
 <td>Control 			Company</td>
 <td>3118</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Goat 			Serum</td>
 <td>Reagent</td>
 <td>Sigma-Aldrich</td>
 <td>G9023</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Incubation 			tray and lid for Immunostaining (Large)</td>
 <td>Material</td>
 <td>RPI 			Corp.</td>
 <td>248270 			(tray) 
 248270-A 			(lid)</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>ImmEdge 			hydrophobic barrier pen</td>
 <td>Material</td>
 <td>Vector 			Laboratories</td>
 <td>H-4000</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Camel's 			Hair Brushes (#1 thickness)</td>
 <td>Material</td>
 <td>Ted 			Pella</td>
 <td>11859</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Pro&#x2010;Long 			Gold Mounting medium</td>
 <td>Reagent</td>
 <td>Invitrogen</td>
 <td>P36930</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>

tissue preparation and immunostaining of mouse sensory nerve fibers innervating skin and limb bones

Detection and primary processing of physical, chemical and thermal sensory stimuli by peripheral sensory nerve fibers is key to sensory perception in animals and humans. These peripheral sensory nerve fibers express a plethora of receptors and ion channel proteins which detect and initiate specific sensory stimuli. Methods are available to characterize the electrical properties of peripheral sensory nerve fibers innervating the skin, which can also be utilized to identify the functional expression of specific ion channel proteins in these fibers. However, similar electrophysiological methods are not available (and are also difficult to develop) for the detection of the functional expression of receptors and ion channel proteins in peripheral sensory nerve fibers innervating other visceral organs, including the most challenging tissues such as bone. Moreover, such electrophysiological methods cannot be utilized to determine the expression of non-excitable proteins in peripheral sensory nerve fibers. Therefore, immunostaining of peripheral/visceral tissue samples for sensory nerve fivers provides the best possible way to determine the expression of specific proteins of interest in these nerve fibers. So far, most of the protein expression studies in sensory neurons have utilized immunostaining procedures in sensory ganglia, where the information is limited to the expression of specific proteins in the cell body of specific types or subsets of sensory neurons. Here we report detailed methods/protocols for the preparation of peripheral/visceral tissue samples for immunostaining of peripheral sensory nerve fibers. We specifically detail methods for the preparation of skin or plantar punch biopsy and bone (femur) sections from mice for immunostaining of peripheral sensory nerve fibers. These methods are not only key to the qualitative determination of protein expression in peripheral sensory neurons, but also provide a quantitative assay method for determining changes in protein expression levels in specific types or subsets of sensory fibers, as well as for determining the morphological and/or anatomical changes in the number and density of sensory fibers during various pathological states. Further, these methods are not confined to the staining of only sensory nerve fibers, but can also be used for staining any types of nerve fibers in the skin, bones and other visceral tissue.

Watch this Scientific Journal Video about Tissue Preparation and Immunostaining of Mouse Sensory Nerve Fibers Innervating Skin and Limb Bones at JoVE.com

Tissue Preparation and Immunostaining of Mouse Sensory Nerve Fibers Innervating Skin and Limb Bones

Immunocytochemical identification of peripheral sensory nerve fiber subtypes (and detection of protein expression therein) are key to the understanding of molecular mechanisms underlying peripheral sensation. Here we describe methods for preparation of peripheral/visceral tissue samples, such as skin and limb bones, for specific immunostaining of peripheral sensory nerve fibers.

Detection and primary processing of physical, chemical and thermal sensory stimuli by peripheral sensory nerve fibers is key to sensory perception in ...

tissue-preparation-immunostaining-mouse-sensory-nerve-fibers

Research

JoVE Journal

Neuroscience

23.0K ビュー.  The University of Iowa. 末梢感覚神経線維のサブタイプの免疫細胞化学的同定（とそこにタンパク質発現の検出）が末梢感覚の分子メカニズムの理解の鍵となります。ここでは、末梢感覚神経線維の特異的免疫染色のための皮膚や四肢骨などの周辺/内臓の組織サンプル、、の調製のための方法を説明します。

ビデオ: Tissue Preparation and Immunostaining of Mouse Sensory Nerve Fibers Innervating Skin and Limb Bones

Immunocytochemical identification of peripheral sensory nerve fiber subtypes (and detection of protein expression therein) are key to the understanding of molecular mechanisms underlying peripheral sensation. Here we describe methods for preparation of peripheral/visceral tissue samples, such as skin and limb bones, for specific immunostaining of peripheral sensory nerve...

tissue preparation and immunostaining of mouse craniofacial tissues and undecalcified bone

Tissue Preparation and Immunostaining of Mouse Craniofacial Tissues and Undecalcified Bone

Here, we present a detailed protocol to detect and quantify protein levels during craniofacial morphogenesis/pathogenesis by immunostaining using mouse craniofacial tissues as examples. In addition, we describe a method for preparation and cryosectioning of undecalcified hard tissues from young mice for...

co-staining blood vessels and nerve fibers in adipose tissue

Co-staining Blood Vessels and Nerve Fibers in Adipose Tissue

New blood vessel formation and sympathetic innervation play pivotal roles in adipose tissue remodeling. However, there remain technical issues in visualizing and quantitatively measuring adipose tissue. Here we present a protocol to successfully label and quantitatively compare the densities of blood vessels and nerve fibers in different adipose...

three-dimensional imaging of nociceptive intraepidermal nerve fibers in human skin biopsies

Three-dimensional Imaging of Nociceptive Intraepidermal Nerve Fibers in Human Skin Biopsies

In order to study the changes of nociceptive intraepidermal nerve fibers (IENFs) in painful neuropathies (PN), we developed protocols that could directly examine three-dimensional morphological changes observed in nociceptive IENFs.  Three-dimensional analysis of IENFs has the potential to evaluate the morphological changes of IENF in...

a method to target and isolate airway-innervating sensory neurons in mice

A Method to Target and Isolate Airway-innervating Sensory Neurons in Mice

Organ specific sensory neurons are difficult to identify. Fast Blue tracing is used to identify nodose neurons innervating the airways for cell sorting. Sorted nodose neurons are used to extract high quality ribonucleic acid (RNA) for sequencing. Using this protocol, gene expression of airway specific neurons is...

flat mount imaging of mouse skin and its application to the analysis of hair follicle patterning and sensory axon morphology

Flat Mount Imaging of Mouse Skin and Its Application to the Analysis of Hair Follicle Patterning and Sensory Axon Morphology

Mammalian skin contains a diverse array of structures - such as hair follicles and nerve endings - that exhibit distinctive patterns of spatial organization. Analyzing skin as a flat mount takes advantage of the 2-dimensional geometry of this tissue to produce full-thickness high-resolution images of skin...

testing sensory nerve function in a surgically denervated mouse model

This video demonstrates testing sensory nerve function in a mouse model by surgically denervating one side and leaving the other as a control. The response to mechanical stimulation confirms the role of sensory...

Testing Sensory Nerve Function in a Surgically Denervated Mouse Model

immunostaining of mouse stria vascularis and tissue mounting

Immunostaining of Mouse Stria Vascularis and Tissue Mounting  

investigation of activated mouse olfactory sensory neurons via combined immunostaining and in situ hybridization

Investigation of Activated Mouse Olfactory Sensory Neurons via Combined Immunostaining and in situ Hybridization

This protocol combines in situ hybridization with immunofluorescence to identify olfactory and vomeronasal receptor genes expressed in olfactory sensory neurons after activation by chemical stimuli in the...

Investigation of Activated Mouse Olfactory Sensory Neurons via Combined Immunostaining and in situ Hybridization

three-dimensional imaging and analysis of mitochondria within human intraepidermal nerve fibers

Three-dimensional Imaging and Analysis of Mitochondria within Human Intraepidermal Nerve Fibers

This protocol uses three-dimensional (3D) imaging and analysis techniques to visualize and quantify nerve-specific mitochondria. The techniques are applicable to other situations where one fluorescent signal is used to isolate a subset of data from another fluorescent signal.

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

Author Spotlight: 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...

Stria Vascularis Microdissection for Single-Nucleus Sequencing or Immunostaining

preparation and immunostaining of myelinating organotypic cerebellar slice cultures

Preparation and Immunostaining of Myelinating Organotypic Cerebellar Slice Cultures

Here we present a method to prepare organotypic slice cultures from mouse cerebellum and myelin sheath staining by immunohistochemistry suitable for investigating mechanisms of myelination and remyelination in the central nervous...

selective tracing of auditory fibers in the avian embryonic vestibulocochlear nerve

Selective Tracing of Auditory Fibers in the Avian Embryonic Vestibulocochlear Nerve

Here we describe a microdissection technique followed by fluorescent dye injection into the acoustic ganglion of early chick embryos for selective tracing of auditory axon fibers in the nerve and...

mouse retinal tissue fixation and immunostaining for pre&#45;embedding immunoelectron microscopy

Mouse Retinal Tissue Fixation and Immunostaining for Pre&#45;Embedding Immunoelectron Microscopy

an isolated semi-intact preparation of the mouse vestibular sensory epithelium for electrophysiology and high-resolution two-photon microscopy

An Isolated Semi-intact Preparation of the Mouse Vestibular Sensory Epithelium for Electrophysiology and High-resolution Two-photon Microscopy

Analysis of vestibular hair cell function is complicated by their location deep within the hardest part of the skull, the petrous temporal bone. Most functional hair cell studies have used acutely isolated hair cells. Here we describe a semi-intact preparation of mouse vestibular epithelium for electrophysiological and two-photon microscopy...

Now, identify the dorsal cutaneous nerves under a dissecting light microscope. These appear as white strands that travel caudally through the translucent fascia of the trunk wall before making sharp bends and entering the loose connective tissue underneath the skin. Next, using ultra-fine forceps, remove the nerves exclusively from the left side of the animal located at anatomical sites T3 to T12 by plucking them from where their segments bend at the trunk wall to their entry sites into the...

in vivo two-photon microscopy of single nerve endings in skin

In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

The protocol for dynamic longitudinal imaging and selective laser lesion of nerve endings in reporter transgenic mice is...

In Vivo Two-Photon Microscopy of Single Nerve Endings in Skin

biological preparation and mechanical technique for determining viscoelastic properties of zonular fibers

Biological Preparation and Mechanical Technique for Determining Viscoelastic Properties of Zonular Fibers

The protocol describes a method for the study of extracellular matrix viscoelasticity and its dependence on protein composition or environmental factors. The matrix system targeted is the mouse zonule. The performance of the method is demonstrated by comparing the viscoelastic behavior of wild-type zonular fibers with those lacking microfibril-associated...

Preparation of Mouse Brain Tissue for Immunoelectron Microscopy

Transmission electron microscopy (TEM) is extremely useful for visualizing microglial, oligodendrocytic, astrocytic, and neuronal subcellular compartments (dendrite, dendritic spine, axon, axon terminal, perikaryon), as well as their intracellular organelles and cytoskeleton, in the central nervous system at high spatial resolution. Combined with TEM, pre-embedding immunocytochemistry allows the discrimination of cellular elements with few distinctive features and identification criteria (e.g., microglial perikarya and processes, when using an antibody against the microglia-specific marker Iba1 (ionized calcium binding adaptor molecule 1; as presented here)), identifying the neurotransmitter contents of cellular elements (e.g., serotonergic) and their ultrastructural localization of soluble or membrane-bound proteins (e.g., 5 HT1A and EphA4 receptors). Here, we describe a protocol for transcardiac perfusion of mice with acrolein fixative, removal and sectioning of the brain, as well as immunoperoxidase-diaminobenzidine (DAB) staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with TEM. When rigorously performed, this technique provides an excellent compromise between optimal ultrastructural preservation and immunocytochemical detection.

We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy.

Transmission electron microscopy (TEM) is extremely useful for visualizing microglial, oligodendrocytic, astrocytic, and neuronal subcellular compartments ...

Imaging Pheromone Sensing in a Mouse Vomeronasal Acute Tissue Slice Preparation

Peter Karlson and Martin L&uuml;scher used the term pheromone for the first time in 19591 to describe chemicals used for intra-species communication. Pheromones are volatile or non-volatile short-lived molecules2 secreted and/or contained in biological fluids3,4, such as urine, a liquid known to be a main source of pheromones3. Pheromonal communication is implicated in a variety of key animal modalities such as kin interactions5,6, hierarchical organisations3 and sexual interactions7,8 and are consequently directly correlated with the survival of a given species9,10,11. In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO)10,12, a paired structure located at the base of the nasal cavity, and enclosed in a cartilaginous capsule. Each VNO has a tubular shape with a lumen13,14 allowing the contact with the external chemical world. The sensory neuroepithelium is principally composed of vomeronasal bipolar sensory neurons (VSNs)15. Each VSN extends a single dendrite to the lumen ending in a large dendritic knob bearing up to 100 microvilli implicated in chemical detection16. Numerous subpopulations of VSNs are present. They are differentiated by the chemoreceptor they express and thus possibly by the ligand(s) they recognize17,18. Two main vomeronasal receptor families, V1Rs and V2Rs19,20,21,22, are composed respectively by 24023 and 12024 members and are expressed in separate layers of the neuroepithelium. Olfactory receptors (ORs)25 and formyl peptide receptors (FPRs)26,27 are also expressed in VSNs.
Whether or not these neuronal subpopulations use the same downstream signalling pathway for sensing pheromones is unknown. Despite a major role played by a calcium-permeable channel (TRPC2) present in the microvilli of mature neurons28 TRPC2 independent transduction channels have been suggested6,29. Due to the high number of neuronal subpopulations and the peculiar morphology of the organ, pharmacological and physiological investigations of the signalling elements present in the VNO are complex.
Here, we present an acute tissue slice preparation of the mouse VNO for performing calcium imaging investigations. This physiological approach allows observations, in the natural environment of a living tissue, of general or individual subpopulations of VSNs previously loaded with Fura-2AM, a calcium dye. This method is also convenient for studying any GFP-tagged pheromone receptor and is adaptable for the use of other fluorescent calcium probes. As an example, we use here a VG mouse line30, in which the translation of the pheromone V1rb2 receptor is linked to the expression of GFP by a polycistronic strategy.

In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO). Here, an acute tissue slice preparation of VNO for performing calcium imaging is described. This physiological approach allows observations of subpopulations and/or individual neurons in a living tissue and is convenient for receptor-ligand identification.

Peter Karlson and Martin L&uuml;scher used the term pheromone for the first time in 19591 to describe chemicals used for intra-species communication. ...

The embryonic chick is a widely used model for the study of peripheral and central ganglion cell projections. In the auditory system, selective labeling of auditory axons within the VIIIth cranial nerve would enhance the study of central auditory circuit development. This approach is challenging because multiple sensory organs of the inner ear contribute to the VIIIth nerve 1. Moreover, markers that reliably distinguish auditory versus vestibular groups of axons within the avian VIIIth nerve have yet to be identified. Auditory and vestibular pathways cannot be distinguished functionally in early embryos, as sensory-evoked responses are not present before the circuits are formed. Centrally projecting VIIIth nerve axons have been traced in some studies, but auditory axon labeling was accompanied by labeling from other VIIIth nerve components 2,3. Here, we describe a method for anterograde tracing from the acoustic ganglion to selectively label auditory axons within the developing VIIIth nerve. First, after partial dissection of the anterior cephalic region of an 8-day chick embryo immersed in oxygenated artificial cerebrospinal fluid, the cochlear duct is identified by anatomical landmarks. Next, a fine pulled glass micropipette is positioned to inject a small amount of rhodamine dextran amine into the duct and adjacent deep region where the acoustic ganglion cells are located. Within thirty minutes following the injection, auditory axons are traced centrally into the hindbrain and can later be visualized following histologic preparation. This method provides a useful tool for developmental studies of peripheral to central auditory circuit formation.

Here we describe a microdissection technique followed by fluorescent dye injection into the acoustic ganglion of early chick embryos for selective tracing of auditory axon fibers in the nerve and hindbrain.

The embryonic chick is a widely used model for the study of peripheral and central ganglion cell projections. In the auditory system, selective labeling ...

Understanding vestibular hair cells function under normal conditions, or how trauma, disease, and aging disrupt this function is a vital step in the development of preventative approaches and/or novel therapeutic strategies. However, the majority of studies looking at abnormal vestibular function have not been at the cellular level but focused primarily on behavioral assays of vestibular dysfunction such as gait analyses and vestibulo-ocular reflex performance. While this work has yielded valuable data about what happens when things go wrong, little information is gleaned regarding the underlying causes of dysfunction. Of the studies that focus on the cellular and subcellular processes that underlie vestibular function, most have relied on acutely isolated hair cells, devoid of their synaptic connections and supporting cell environment. Therefore, a major technical challenge has been access to the exquisitely sensitive vestibular hair cells in a preparation that is least disrupted, physiologically. Here we demonstrate a semi-intact preparation of the mouse vestibular sensory epithelium that retains the local micro-environment including hair cell/primary afferent complexes.

Analysis of vestibular hair cell function is complicated by their location deep within the hardest part of the skull, the petrous temporal bone. Most functional hair cell studies have used acutely isolated hair cells. Here we describe a semi-intact preparation of mouse vestibular epithelium for electrophysiological and two-photon microscopy studies.

Understanding vestibular hair cells function  under normal conditions, or how trauma, disease, and aging disrupt this  function is a vital step in the ...

Skin is a highly heterogeneous tissue. Intra-dermal structures include hair follicles, arrector pili muscles, epidermal specializations (such as Merkel cell clusters), sebaceous glands, nerves and nerve endings, and capillaries. The spatial arrangement of these structures is tightly controlled on a microscopic scale - as seen, for example, in the orderly arrangement of cell types within a single hair follicle - and on a macroscopic scale - as seen by the nearly identical orientations of thousands of hair follicles within a local region of skin. Visualizing these structures without physically sectioning the skin is possible because of the 2-dimensional geometry of this organ. In this protocol, we show that mouse skin can be dissected, fixed, permeabilized, stained, and clarified as an intact two dimensional object, a flat mount. The protocol allows for easy visualization of skin structures in their entirety through the full thickness of large areas of skin by optical sectioning and reconstruction. Images of these structures can also be integrated with information about position and orientation relative to the body axes.

Mammalian skin contains a diverse array of structures - such as hair follicles and nerve endings - that exhibit distinctive patterns of spatial organization. Analyzing skin as a flat mount takes advantage of the 2-dimensional geometry of this tissue to produce full-thickness high-resolution images of skin structures.

Skin is a highly heterogeneous tissue. Intra-dermal structures include hair follicles, arrector pili muscles, epidermal specializations (such as Merkel ...

Whole-mount Imaging of Mouse Embryo Sensory Axon Projections

The visualization of full-length neuronal projections in embryos is essential to gain an understanding of how mammalian neuronal networks develop. Here we describe a method to label in situ a subset of dorsal root ganglion (DRG) axon projections to assess their phenotypic characteristics using several genetically manipulated mouse lines. The TrkA-positive neurons are nociceptor neurons, dedicated to the transmission of pain signals. We utilize a TrkAtaulacZ mouse line to label the trajectories of all TrkA-positive peripheral axons in the intact mouse embryo. We further breed the TrkAtaulacZ line onto a Bax null background, which essentially abolishes neuronal apoptosis, in order to assess growth-related questions independently of possible effects of genetic manipulations on neuronal survival. Subsequently, genetically modified mice of interest are bred with the TrkAtaulacZ/Bax null line and are then ready for study using the techniques described herein. This presentation includes detailed information on mouse breeding plans, genotyping at the time of dissection, tissue preparation, staining and clearing to allow for visualization of full-length axonal trajectories in whole-mount preparation.

We present here an optimized protocol to genotype, stain and prepare fetal mice for the imaging of peripheral nociceptor axon projections in the whole animal, as an effective method to assess sensory axon growth phenotypes in developing genetically engineered mice.

The visualization of full-length neuronal projections in embryos is essential to gain an understanding of how mammalian neuronal networks develop. Here we ...

The goal of this protocol is to study mitochondria within intraepidermal nerve fibers. Therefore, 3D imaging and analysis techniques were developed to isolate nerve-specific mitochondria and evaluate disease-induced alterations of mitochondria in the distal tip of sensory nerves. The protocol combines fluorescence immunohistochemistry, confocal microscopy and 3D image analysis techniques to visualize and quantify nerve-specific mitochondria. Detailed parameters are defined throughout the procedures in order to provide a concrete example of how to use these techniques to isolate nerve-specific mitochondria. Antibodies were used to label nerve and mitochondrial signals within tissue sections of skin punch biopsies, which was followed by indirect immunofluorescence to visualize nerves and mitochondria with a green and red fluorescent signal respectively. Z-series images were acquired with confocal microscopy and 3D analysis software was used to process and analyze the signals. It is not necessary to follow the exact parameters described within, but it is important to be consistent with the ones chosen throughout the staining, acquisition and analysis steps. The strength of this protocol is that it is applicable to a wide variety of circumstances where one fluorescent signal is used to isolate other signals that would otherwise be impossible to study alone.

This protocol uses three-dimensional (3D) imaging and analysis techniques to visualize and quantify nerve-specific mitochondria. The techniques are applicable to other situations where one fluorescent signal is used to isolate a subset of data from another fluorescent signal.

The goal of this protocol is to study mitochondria within intraepidermal nerve fibers. Therefore, 3D imaging and analysis techniques were developed to ...

Somatosensory nerves transduce thermal, mechanical, chemical, and noxious stimuli caused by both endogenous and environmental agents. The cell bodies of these afferent neurons are located within the sensory ganglia. Sensory ganglia innervate a specific organ or portion of the body. For instance, the dorsal root ganglia (DRG) are located in the vertebral column and extend processes throughout the body and limbs. The trigeminal ganglia are located in the skull and innervate the face, and upper airways. Vagal afferents of the nodose ganglia extend throughout the gut, heart, and lungs. The nodose neurons control a diverse array of functions such as: respiratory rate, airway irritation, and cough reflexes. Thus, to understand and manipulate their function, it is critical to identify and isolate airway specific neuronal sub-populations. In the mouse, the airways are exposed to a fluorescent tracer dye, Fast Blue, for retrograde tracing of airway-specific nodose neurons. The nodose ganglia are dissociated and fluorescence activated cell (FAC) sorting is used to collect dye positive cells. Next, high quality ribonucleic acid (RNA) is extracted from dye positive cells for next generation sequencing. Using this method airway specific neuronal gene expression is determined.

Organ specific sensory neurons are difficult to identify. Fast Blue tracing is used to identify nodose neurons innervating the airways for cell sorting. Sorted nodose neurons are used to extract high quality ribonucleic acid (RNA) for sequencing. Using this protocol, gene expression of airway specific neurons is determined.

Somatosensory nerves transduce thermal, mechanical, chemical, and noxious stimuli caused by both endogenous and environmental agents. The cell bodies of ...

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog (Rana catesbeiana)

The study of hearing and balance rests upon insights drawn from biophysical studies of model systems. One such model, the sacculus of the American bullfrog, has become a mainstay of auditory and vestibular research. Studies of this organ have revealed how sensory cells hair can actively detect signals from the environment. Because of these studies, we now better understand the mechanical gating and localization of a hair cell&#39;s transduction channels, calcium&#39;s role in mechanical adaptation, and the identity of hair cell currents. This highly accessible organ continues to provide insight into the workings of hair cells. Here we describe the preparation of the bullfrog&#39;s sacculus for biophysical studies on its hair cells. We include the complete dissection procedure and provide specific protocols for the preparation of the sacculus in specific contexts. We additionally include representative results using this preparation, including the calculation of a hair bundle&#39;s instantaneous force-displacement relation and measurement of a bundle&#39;s spontaneous oscillation.

Physiological Preparation of Hair Cells from the Sacculus of the American Bullfrog Rana catesbeiana

The American bullfrog&#39;s (Rana catesbeiana) sacculus permits direct examination of hair-cell physiology. Here the dissection and preparation of the bullfrog&#39;s sacculus for biophysical studies is described. We show representative experiments from these hair cells, including the calculation of a bundle&#39;s force-displacement relation and measurement of its unforced motion.

The study of hearing and balance rests upon insights drawn from biophysical studies of model systems. One such model, the sacculus of the American ...

Quadruple Immunostaining of the Olfactory Bulb for Visualization of Olfactory Sensory Axon Molecular Identity Codes

The mouse olfactory system is often used to study mechanisms of neural circuit formation&#12288;because of its simple anatomical structure. An Olfactory Sensory Neuron (OSN) is a bipolar cell with a single dendrite and a single unbranched axon. An OSN expresses only one Olfactory Receptor (OR) gene, OSNs expressing a given type of OR converge their axons to a few sets of invariant glomeruli in the Olfactory Bulb (OB). A remarkable feature of OSN projection is that the expressed ORs play instructive roles in axonal projection. ORs regulate the expression of multiple axon-sorting molecules and generate the combinatorial molecular code of axon-sorting molecules at the OSN axon termini. Thus, to understand the molecular mechanisms of OR-specific axon guidance mechanisms, it is vital to characterize their expression profiles at the OSN axon termini within the same glomerulus. The aim of this article was to introduce methods for collecting as many glomeruli as possible on a single OB section and for performing immunostaining using multiple antibodies. This would allow the comparison and analysis of the expression patterns of axon-sorting molecules without staining variation between OB sections.

Olfactory sensory neurons express a wide variety of axon-sorting molecules to establish proper neural circuitry. This protocol describes an immunohistochemical staining method to visualize combinatorial expressions of axon-sorting molecules at the axon termini of olfactory sensory neurons.

The mouse olfactory system is often used to study mechanisms of neural circuit formation&#12288;because of its simple anatomical structure. An Olfactory ...