This research was supported by R00 DC011780 (JPM: NINDS, NIH), F30 DC011673 (GFH: NINDS, NIH) and UT Southwestern startup funds (JPM).

All experiments were carried out in accordance with protocols approved by the UT Southwestern Institutional Animal Care and Use Committee, and were chosen so as to minimize stress, discomfort, and pain experienced by the experimental animals.
1. Dissection Chamber
A custom dissection chamber and small, thin plastic plank are required for best results (Figure 1). Construct or obtain such a chamber in advance of attempting this protocol.
<p class="j...

<ol>
	<li>Bruce, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+exteroceptive+block+to+pregnancy+in+the+mouse.">An exteroceptive block to pregnancy in the mouse.</a> Nature. 184, 105 (1959).</li><li>Bellringer, J. F., Pratt, H. P., Keverne, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+the+vomeronasal+organ+and+prolactin+in+pheromonal+induction+of+delayed+implantation+in+mice.">Involvement of the vomeronasal organ and prolactin in pheromonal induction of delayed implantation in mice.</a> J Reprod Fertil. 59, 223-228 (1980).</li><li>Bean, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+agonistic+behavior+by+the+dual+olfactory+system+in+male+mice.">Modulation of agonistic behavior by the dual olfactory system in male mice.</a> Physiol Behav. 29, 433-437 (1982).</li><li>Meredith, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vomeronasal+organ+removal+before+sexual+experience+impairs+male+hamster+mating+behavior.">Vomeronasal organ removal before sexual experience impairs male hamster mating behavior.</a> Physiol Behav. 36, 737-743 (1986).</li><li>Hendrickson, R. C., Krauthamer, S., Essenberg, J. M., Holy, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+shapes+sex+selectivity+in+the+mouse+accessory+olfactory+bulb.">Inhibition shapes sex selectivity in the mouse accessory olfactory bulb.</a> J Neurosci. 28, 12523-12534 (2008).</li><li>Ben-Shaul, Y., Katz, L. C., Mooney, R., Dulac, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+vomeronasal+stimulation+reveals+sensory+encoding+of+conspecific+and+allospecific+cues+by+the+mouse+accessory+olfactory+bulb.">In vivo vomeronasal stimulation reveals sensory encoding of conspecific and allospecific cues by the mouse accessory olfactory bulb.</a> Proc Natl Acad Sci U S A. 107, (2010).</li><li>Tolokh, I. I., Fu, X., Holy, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliable+sex+and+strain+discrimination+in+the+mouse+vomeronasal+organ+and+accessory+olfactory+bulb.">Reliable sex and strain discrimination in the mouse vomeronasal organ and accessory olfactory bulb.</a> The Journal of neuroscience : the official journal of the Society for Neuroscience. 33, 13903-13913 (2013).</li><li>Luo, M., Fee, M. S., Katz, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Encoding+pheromonal+signals+in+the+accessory+olfactory+bulb+of+behaving+mice.">Encoding pheromonal signals in the accessory olfactory bulb of behaving mice.</a> Science. 299, 1196-1201 (2003).</li><li>Binns, K. E., Brennan, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+electrophysiological+activity+in+the+accessory+olfactory+bulb+and+medial+amygdala+associated+with+mate+recognition+in+mice.">Changes in electrophysiological activity in the accessory olfactory bulb and medial amygdala associated with mate recognition in mice.</a> Eur J Neurosci. 21, 2529-2537 (2005).</li><li>Leszkowicz, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noradrenaline-induced+enhancement+of+oscillatory+local+field+potentials+in+the+mouse+accessory+olfactory+bulb+does+not+depend+on+disinhibition+of+mitral+cells.">Noradrenaline-induced enhancement of oscillatory local field potentials in the mouse accessory olfactory bulb does not depend on disinhibition of mitral cells.</a> Eur J Neurosci. 35, 1433-1445 (2012).</li><li>Ames, A., Gurian, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+Recordings+from+Isolated+Mammalian+Retina+Mounted+as+a+Membrane.">Electrical Recordings from Isolated Mammalian Retina Mounted as a Membrane.</a> Arch Ophthalmol. 70, 837-841 (1963).</li><li>Flock, A. F., Strelioff, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+hair+cells+in+isolated+coils+from+the+guinea+pig+cochlea.">Studies on hair cells in isolated coils from the guinea pig cochlea.</a> Hear Res. 15, 11-18 (1984).</li><li>Woodbury, C. J., Ritter, A. M., Koerber, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+anatomy+of+individual+rapidly+adapting+low-threshold+mechanoreceptors+innervating+the+'hairy'+skin+of+newborn+mice:+early+maturation+of+hair+follicle+afferents.">Central anatomy of individual rapidly adapting low-threshold mechanoreceptors innervating the 'hairy' skin of newborn mice: early maturation of hair follicle afferents.</a> J Comp Neurol. 436, 304-323 (2001).</li><li>Llinas, R., Muhlethaler, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+electrophysiological+study+of+the+in+vitro,+perfused+brain+stem-cerebellum+of+adult+guinea-pig.">An electrophysiological study of the in vitro, perfused brain stem-cerebellum of adult guinea-pig.</a> The Journal of physiology. 404, 215-240 (1988).</li><li>Riviere, S., Challet, L., Fluegge, D., Spehr, M., Rodriguez, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formyl+peptide+receptor-like+proteins+are+a+novel+family+of+vomeronasal+chemosensors.">Formyl peptide receptor-like proteins are a novel family of vomeronasal chemosensors.</a> Nature. 459, 574-577 (2009).</li><li>Meeks, J. P., Holy, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ex+vivo+preparation+of+the+intact+mouse+vomeronasal+organ+and+accessory+olfactory+bulb.">An ex vivo preparation of the intact mouse vomeronasal organ and accessory olfactory bulb.</a> J Neurosci Methods. 177, 440-447 (2009).</li><li>Leinders-Zufall, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasensitive+pheromone+detection+by+mammalian+vomeronasal+neurons.">Ultrasensitive pheromone detection by mammalian vomeronasal neurons.</a> Nature. 405, 792-796 (2000).</li><li>Kato, H. K., Chu, M. W., Isaacson, J. S., Komiyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+sensory+representations+in+the+olfactory+bulb:+modulation+by+wakefulness+and+experience.">Dynamic sensory representations in the olfactory bulb: modulation by wakefulness and experience.</a> 76, 962-975 (2012).</li><li>Meeks, J. P., Arnson, H. A., Holy, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Representation+and+transformation+of+sensory+information+in+the+mouse+accessory+olfactory+system.">Representation and transformation of sensory information in the mouse accessory olfactory system.</a> Nature. 13, 723-730 (2010).</li></ol>

The VNO-AOB ex vivo preparation described in this protocol is a useful alternative to anesthetized in vivo5-7 and acute live slice17 experiments of AOB function. Unlike acute AOB slice experiments, which also expose circuit elements for electrophysiological and optical recordings, this preparation retains all sensory afferents and intra-AOB connections. Although this can also be said of anesthetized in vivo approaches, the presence of anesthetics necessarily alter...

Sensory processing in the mammalian brain typically spans multiple reciprocally-connected neuronal circuits, each of which extracts particular features from sensory input. In sensory pathways, early information processing is vital for normal perception and behavior. In the accessory olfactory system (AOS), the accessory olfactory bulb (AOB) is the principal neural circuit linking the sensory periphery to downstream structures that dictate hormonal balance1,2, aggression3, and arousal4. As such, information processing within this circuit is strongly linked to changes in animal behavior.
The accessory olfactory bulb is located in mice and rats at the dorsal/caudal/posterior aspect of the main olfactory bulb (MOB) beneath the dense, vascularized rhinal sinus. The AOB receives afferent innervation from axons of peripheral vomeronasal sensory neurons (VSNs) that reside in the vomeronasal organ (VNO), a small blind-ended tube in the anterior snout just above the soft palate. These axons traverse the delicate sheet of septal tissue at the medial boundary of the nasal passages. Several studies have probed AOB neural responses to sources of AOS odors (such as mouse urine) in vivo using anesthetized mice5-7 or freely-exploring animals8. The heroic anesthetized in vivo studies involved (a) tracheotomies to ensure deep anesthesia and prevent the aspiration of liquid stimuli5-7, (b) stimulation of the sympathetic cervical ganglion6 or direct cannulation of the vomeronasal organ5,7 to introduce nonvolatile odors and (c) craniotomies with or without frontal lobe ablations to allow electrode advancement into the AOB6. Awake/behaving studies8-10 involved surgical implantation of a microdrive. In sum, these experimental paradigms are powerful, but extremely difficult and often require anesthesia.
Interestingly, several studies attempted to maintain sensory structures and downstream neural circuits alive outside the body (ex vivo) with some success11-15. Because the connections between the VNO and AOB remain ipsilateral, and because the midline septal tissue can be exposed to oxygenated superfusate in a single hemisphere, we sought to develop such a single-hemisphere ex vivo approach to isolate these structures while maintaining their functional connectivity. We recently succeeded in achieving this goal16. This preparation keeps both the VNO and AOB alive and functionally connected for at least 4 - 6 hr because both the axons (along the midline soft septal tissue) and AOB are relatively shallow &#60;600 &#181;m features that are accessible to superfused oxygenated artificial cerebrospinal fluid (aCSF). This VNO-AOB ex vivo preparation allows introduction of controlled stimuli into the VNO via a thin cannula, and direct visual access to the small AOB for targeted electrode placement and/or live fluorescence microscopy. This method is advantageous if one desires to study these circuits in the absence of anesthetics. Because this approach severs centrifugal connections, it is not well suited to inquiries into centrifugal modulation of AOB function. The VNO-AOB ex vivo preparation is difficult to learn, but once achieved produces a reliable platform upon which to investigate circuit organization, information processing, and neural plasticity in this powerful sensory circuit.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Straight Scissors</td>
			<td>Fine Science Tools</td>
			<td>14002-14</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine Scissors-Straight</td>
			<td>Fine Science Tools</td>
			<td>14060-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine Scissors-Curved</td>
			<td>Fine Science Tools</td>
			<td>14061-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Adson Forceps</td>
			<td>Fine Science Tools</td>
			<td>11006-12</td>
			<td></td>
		</tr>
		<tr>
			<td>#3 Scalpel Handle</td>
			<td>Fine Science Tools</td>
			<td>10003-12</td>
			<td></td>
		</tr>
		<tr>
			<td>#11 Scalpel Blades</td>
			<td>Fisher Scientific</td>
			<td>3120030</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Carbon Steel Razor Blades</td>
			<td>Fisher Scientific</td>
			<td>12-640</td>
			<td></td>
		</tr>
		<tr>
			<td>35 mm Petri Dish</td>
			<td>Fisher Scientific</td>
			<td>08-772-21</td>
			<td></td>
		</tr>
		<tr>
			<td>Dissection Chamber</td>
			<td>Custom&#160;</td>
			<td>N/A</td>
			<td>See Fig. 1</td>
		</tr>
		<tr>
			<td>Delrin plastic plank 0.6 cm x 1.5 cm x 0.1 cm</td>
			<td>Custom&#160;</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Dow Corning Silicon Vacuum grease</td>
			<td>Fisher Scientific</td>
			<td>146355D</td>
			<td></td>
		</tr>
		<tr>
			<td>#5 Forceps, Student</td>
			<td>Fine Science Tools</td>
			<td>91150-20</td>
			<td></td>
		</tr>
		<tr>
			<td>#5 Forceps, Biologie Tip</td>
			<td>Fine Science Tools</td>
			<td>11295-10</td>
			<td></td>
		</tr>
		<tr>
			<td>#5 Forceps, Student</td>
			<td>Fine Science Tools</td>
			<td>91150-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Vannas Spring Scissors</td>
			<td>Fine Science Tools</td>
			<td>15000-08</td>
			<td></td>
		</tr>
		<tr>
			<td>0.0045&#34; Polyimide Tubing</td>
			<td>A-M Systems</td>
			<td>823400</td>
			<td></td>
		</tr>
		<tr>
			<td>1/16&#34; Male Luer</td>
			<td>Cole-Parmer</td>
			<td>EW-45505-00</td>
			<td></td>
		</tr>
		<tr>
			<td>1/16&#34; Tubing</td>
			<td>Fisher Scientific</td>
			<td>14-171-129</td>
			<td></td>
		</tr>
		<tr>
			<td>Two ton epoxy</td>
			<td>Grainger</td>
			<td>5E157</td>
			<td></td>
		</tr>
		<tr>
			<td>ValveBank Pressurized Perfusion Kit</td>
			<td>AutoMate Scientific</td>
			<td>09-16</td>
			<td></td>
		</tr>
		<tr>
			<td>ValveLink digital/manual controller</td>
			<td>AutoMate Scientific</td>
			<td>01-18</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>CaCl2 dihydrate</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl2 hexahydrate</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>NaHCO3</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>NaH2PO4</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>myo-inositol</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>Na-pyruvate</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>Na-ascorbate</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES buffer</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr>
			<td>glucose</td>
			<td>Sigma-Aldrich</td>
			<td>various</td>
			<td></td>
		</tr>
	</tbody>
</table>

ex vivo preparations of the intact vomeronasal organ and accessory olfactory bulb

The mouse accessory olfactory system (AOS) is a specialized sensory pathway for detecting nonvolatile social odors, pheromones, and kairomones. The first neural circuit in the AOS pathway, called the accessory olfactory bulb (AOB), plays an important role in establishing sex-typical behaviors such as territorial aggression and mating. This small (&#60;1 mm3) circuit possesses the capacity to distinguish unique behavioral states, such as sex, strain, and stress from chemosensory cues in the secretions and excretions of conspecifics. While the compact organization of this system presents unique opportunities for recording from large portions of the circuit simultaneously, investigation of sensory processing in the AOB remains challenging, largely due to its experimentally disadvantageous location in the brain. Here, we demonstrate a multi-stage dissection that removes the intact AOB inside a single hemisphere of the anterior mouse skull, leaving connections to both the peripheral vomeronasal sensory neurons (VSNs) and local neuronal circuitry intact. The procedure exposes the AOB surface to direct visual inspection, facilitating electrophysiological and optical recordings from AOB circuit elements in the absence of anesthetics. Upon inserting a thin cannula into the vomeronasal organ (VNO), which houses the VSNs, one can directly expose the periphery to social odors and pheromones while recording downstream activity in the AOB. This procedure enables controlled inquiries into AOS information processing, which can shed light on mechanisms linking pheromone exposure to changes in behavior.

Achieving success with this preparation takes extensive practice, and has several steps at which it can fail. One should expect to require many attempts before achieving success. The custom dissection chamber is required for successful completion of this protocol, and should be obtained prior to starting the later stages of the dissection. The chamber design presented in Figure 1 is sufficient for this purpose, and can be made of relatively inexpensive plastics with minimal machining demands. If one lack...

Watch this Scientific Journal Video about Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb at JoVE.com

Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

The mouse accessory olfactory bulb (AOB) has been difficult to study in the context of sensory coding. Here, we demonstrate a dissection that produces an ex vivo preparation in which AOB neurons remain functionally connected to their peripheral inputs, facilitating research into information processing of mouse pheromones and kairomones.

Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

The mouse accessory olfactory system (AOS) is a specialized sensory pathway for detecting nonvolatile social odors, pheromones, and kairomones. The first ...

ex-vivo-preparations-intact-vomeronasal-organ-accessory-olfactory

Research

JoVE Journal

Neuroscience

10.6K vistas.  UT Southwestern Medical Center.  El bulbo olfativo accesorio ratón (AOB) ha sido difícil de estudiar en el contexto de la codificación sensorial. Este sentido, demuestran una disección que produce un vivo preparación ex en el que las neuronas AOB permanecen funcionalmente conectados a sus entradas de periferia, facilitando la investigación sobre el procesamiento de información de las feromonas del ratón y kairomones. 

Video: Ex Vivo Preparations of the Intact Vomeronasal Organ and Accessory Olfactory Bulb

The mouse accessory olfactory bulb (AOB) has been difficult to study in the context of sensory coding. Here, we demonstrate a dissection that produces an ex vivo preparation in which AOB neurons remain functionally connected to their peripheral inputs, facilitating research into information processing of mouse pheromones and...

imaging neuronal responses in slice preparations of vomeronasal organ expressing a genetically encoded calcium sensor

Imaging Neuronal Responses in Slice Preparations of Vomeronasal Organ Expressing a Genetically Encoded Calcium Sensor

The vomeronasal organ (VNO) detects intraspecies chemical signals that convey social and reproductive information. We have performed Ca2+ imaging experiments using transgenic mice expressing G-CaMP2 in VNO tissue. This approach allows us to analyze the complicated response patterns of the vomeronasal neurons to large numbers of pheromone...

ex-vivo brain slices preparation from mouse brain tissue for studying hippocampal-cortical and olfactory bulb circuits

Ex-Vivo Brain Slices Preparation from Mouse Brain Tissue for Studying Hippocampal-Cortical and Olfactory Bulb Circuits

spatiotemporal mapping of motility in ex vivo preparations of the intestines

Spatiotemporal Mapping of Motility in Ex Vivo Preparations of the Intestines

Recently available video recording and spatiotemporal mapping (STmap) techniques make it possible to visualize and quantify both propagating and mixing patterns of intestinal motility. The goal of this protocol is to explain the generation and analysis of STmaps using the GastroIntestinal Motility Monitoring (GIMM)...

Spatiotemporal Mapping of Motility in Ex Vivo Preparations of the Intestines

ex-vivo circuit-wide recordings from hippocampal-cortical and olfactory bulb slices using high-density microelectrode array (hd-mea)

Ex-Vivo Circuit-Wide Recordings from Hippocampal-Cortical and Olfactory Bulb Slices Using High-Density Microelectrode Array (HD-MEA)

preparation of mouse vomeronasal organ for vibratome sectioning

This video outlines the isolation of a mouse vomeronasal organ (VNO) and tissue preparation for vibratome sectioning. Sections are used to characterize the biophysical and physiological attributes of a specific group of sensory...

Preparation of Mouse Vomeronasal Organ for Vibratome Sectioning

quadruple immunostaining of the olfactory bulb for visualization of olfactory sensory axon molecular identity codes

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

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...

Use the tip of fine forceps to separate both cartilage VNO capsules from the central bone, while keeping the vomer bone pinned down at the rear part. Make sure the medial cartilage wall that was previously attached to the vomer bone is...

in-depth physiological analysis of defined cell populations in acute tissue slices of the mouse vomeronasal organ

In-depth Physiological Analysis of Defined Cell Populations in Acute Tissue Slices of the Mouse Vomeronasal Organ

Here, we describe a physiological approach that allows identification and in-depth analysis of a defined population of sensory neurons in acute coronal tissue slices of the mouse vomeronasal organ using whole-cell patch-clamp recordings.

targeting olfactory bulb neurons using combined in vivo electroporation and gal4-based enhancer trap zebrafish lines

Targeting Olfactory Bulb Neurons Using Combined In Vivo Electroporation and Gal4-Based Enhancer Trap Zebrafish Lines

The temporal and spatial resolution of genetic manipulations determines the spectrum of biological phenomena that they can perturb.  Here we use temporally and spatially discrete in vivo electroporation, combined with transgenic lines of zebrafish, to induce expression of a GFP transgene specifically in neurons of the developing olfactory...

Targeting Olfactory Bulb Neurons Using Combined In Vivo Electroporation and Gal4-Based Enhancer Trap Zebrafish Lines

the ex vivo colon organ culture and its use in antimicrobial host defense studies

The Ex Vivo Colon Organ Culture and Its Use in Antimicrobial Host Defense Studies

The ex vivo organ culture allows investigation of biological processes in the context of the intact tissue architecture. Here, we introduce a method of ex vivo culture of the mouse colon, which can be used to study innate immunity and antimicrobial host defense in the intestine.

The Ex Vivo Colon Organ Culture and Its Use in Antimicrobial Host Defense Studies

recording temperature-induced neuronal activity through monitoring calcium changes in the olfactory bulb of xenopus laevis

Recording Temperature-induced Neuronal Activity through Monitoring Calcium Changes in the Olfactory Bulb of Xenopus laevis

Here we describe a protocol for measuring and analyzing temperature responses in the olfactory bulb of Xenopus laevis. Olfactory receptor neurons and mitral cells are differentially stained, after which calcium changes are recorded, reflecting a sensitivity of some neural networks in the bulb to temperature drops induced at the nose.

Recording Temperature-induced Neuronal Activity through Monitoring Calcium Changes in the Olfactory Bulb of Xenopus laevis

ex vivo corneal organ culture model for wound healing studies

Ex Vivo Corneal Organ Culture Model for Wound Healing Studies

A protocol for an ex vivo corneal organ culture model useful for wound healing studies is described. This model system can be used to assess the effects of agents to promote regenerative healing or drug toxicity in an organized 3D multicellular...

imaging odor-evoked activities in the mouse olfactory bulb using optical reflectance and autofluorescence signals

Imaging Odor-Evoked Activities in the Mouse Olfactory Bulb using Optical Reflectance and Autofluorescence Signals

This article presents the protocols of intrinsic optical signals and flavoproteins autofluorescence signals imaging to map odor-evoked activities at the surface of the olfactory bulb in...

the use of ex vivo whole-organ imaging and quantitative tissue histology to determine the bio-distribution of fluorescently labeled molecules

The Use of Ex Vivo Whole-organ Imaging and Quantitative Tissue Histology to Determine the Bio-distribution of Fluorescently Labeled Molecules

Ex vivo whole-organ imaging is a rapid method for determining the relative concentrations of fluorescently labeled compounds within and between tissues or treatment groups. Conversely, quantitative fluorescence histology, while more labor intensive, allows for the quantification of the absolute tissue levels of labeled...

The Use of Ex Vivo Whole-organ Imaging and Quantitative Tissue Histology to Determine the Bio-distribution of Fluorescently Labeled Molecules

establishing villous and decidual organ cultures as ex vivo models of human maternal-fetal interface

Next, place transwell inserts with 0.4-micron pores into individual wells of a 6-well tissue culture plate and coat each insert with 100 microliters of the extracellular matrix suspension. Place the plate on ice, and rinse the specimens 2 times in collection medium, transferring the tissue to a sterile petri dish under a dissecting microscope after the second...

Establishing Villous and Decidual Organ Cultures as Ex Vivo Models of Human Maternal-Fetal Interface

This video demonstrates the establishment of primary human placental villous and decidual organ cultures in ex vivo conditions. These models are well-suited for studying pathogenesis at the human maternal-fetal...

an ex vivo gut organ culture system to study host-microbiota interactions

In this video, we describe the methodology for setting up an ex vivo gut organ culture system to study the interactions between mouse intestinal tissue fragments and specific gut bacteria. The device consists of two pairs of input-output ports, the first connecting the intestinal tissue lumen and supplying the specific bacterial suspension into it, and the second continuously supplying media to the device&#39;s wells to maintain ex vivo tissue...

An Ex Vivo Gut Organ Culture System to Study Host-Microbiota Interactions

the olfactory system as a model to study axonal growth patterns and morphology in vivo

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over...

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

recording and analyzing multimodal large-scale neuronal ensemble dynamics on cmos-integrated high-density microelectrode array

Author Spotlight: Advancing Large-Scale Neural Dynamics Through HD-MEA Technology

Here, we employ HD-MEA to delve into computational dynamics of large-scale neuronal ensembles, particularly in hippocampal, olfactory bulb circuits, and human neuronal networks. Capturing spatiotemporal activity, combined with computational tools, provides insights into neuronal ensemble complexity. The method enhances understanding of brain functions, potentially identifying biomarkers and treatments for neurological...

Multimodal Large-Scale Neural Recordings and Analysis on HD-MEA 

https://cloudfront.jove.com/CDNSource/teasers/66473_b.jpg

Multielectrode Array Recordings of the Vomeronasal Epithelium

Understanding neural circuits requires methods to record from many neurons simultaneously. For in vitro studies, one currently available technology is planar multielectrode array (MEA) recording. Here we document the use of MEAs to study the mouse vomeronasal organ (VNO), which plays an essential role in the detection of pheromones and social cues via a diverse population of sensory neurons expressing hundreds of types of receptors. Combining MEA recording with a robotic liquid handler to deliver chemical stimuli, the sensory responses of a large and diverse population of neurons can be recorded. The preparation allows us to remove the intact neuroepithelium of the VNO from the mouse and stimulate with a battery of chemicals or potential ligands while monitoring the electrical activity of the neurons for several hours. Therefore, this technique serves as a useful method for assessing ligand activity as well as exploring the properties of receptor neurons. We present the techniques needed to prepare the vomeronasal epithelium, MEA recording, and chemical stimulation.

Multielectrode array (MEA) recordings provide a method for studying the electrical activity of large populations of neurons. Here, we present the details of a MEA preparation to record from the mouse vomeronasal epithelium while simultaneously stimulating the tissue.

Understanding neural circuits requires methods to record from many neurons simultaneously. For in vitro studies, one currently available technology is ...

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding fundamental biological mechanisms. Striking progress has been particularly evident in Drosophila, whose extensive toolkit of mutants and transgenic lines provides a convenient model to study evolutionarily-conserved developmental and cell biological mechanisms. We are interested in understanding the mechanisms that control cell fate specification in the adult peripheral nervous system (PNS) in Drosophila. Bristles that cover the head, thorax, abdomen, legs and wings of the adult fly are individual mechanosensory organs, and have been studied as a model system for understanding mechanisms of Notch-dependent cell fate decisions. Sensory organ precursor (SOP) cells of the microchaetes (or small bristles), are distributed throughout the epithelium of the pupal thorax, and are specified during the first 12 hours after the onset of pupariation. After specification, the SOP cells begin to divide, segregating the cell fate determinant Numb to one daughter cell during mitosis. Numb functions as a cell-autonomous inhibitor of the Notch signaling pathway.
Here, we show a method to follow protein dynamics in SOP cell and its progeny within the intact pupal thorax using a combination of tissue-specific Gal4 drivers and GFP-tagged fusion proteins 1,2.This technique has the advantage over fixed tissue or cultured explants because it allows us to follow the entire development of an organ from specification of the neural precursor to growth and terminal differentiation of the organ. We can therefore directly correlate changes in cell behavior to changes in terminal differentiation. Moreover, we can combine the live imaging technique with mosaic analysis with a repressible cell marker (MARCM) system to assess the dynamics of tagged proteins in mitotic SOPs under mutant or wildtype conditions. Using this technique, we and others have revealed novel insights into regulation of asymmetric cell division and the control of Notch signaling activation in SOP cells (examples include references 1-6,7 ,8).

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding ...

In vivo electroporation is a powerful method for delivering DNA expression plasmids, RNAi reagents, and morpholino anti-sense oligonucleotides to specific regions of developing embryos, including those of C. elegans, chick, Xenopus, zebrafish, and mouse 1. In zebrafish, in vivo electroporation has been shown to have excellent spatial and temporal resolution for the delivery of these reagents 2-7. The temporal resolution of this method is important because it allows for incorporation of these reagents at specific stages in development. Furthermore, because expression from electroporated vectors occurs within 6 hours 7, this method is more timely than transgenic approaches. While the spatial resolution can be extremely precise when targeting a single cell 2, 6, it is often preferable to incorporate reagents into a specific cell population within a tissue or structure. When targeting multiple cells, in vivo electroporation is efficient for delivery to a specific region of the embryo; however, particularly within the developing nervous system, it is difficult to target specific cell types solely through spatially discrete electroporation. Alternatively, enhancer trap transgenic lines offer excellent cell type-specific expression of transgenes 8. Here we describe an approach that combines transgenic Gal4-based enhancer trap lines 8 with spatially discrete in vivo electroporation 7, 9 to specifically target developing neurons of the zebrafish olfactory bulb. The Et(zic4:Gal4TA4,UAS:mCherry)hzm5 (formerly GA80_9) enhancer trap line previously described 8, displays targeted transgenic expression of mCherry mediated by a zebrafish optimized Gal4 (KalTA4) transcriptional activator in multiple regions of the developing brain including hindbrain, cerebellum, forebrain, and the olfactory bulb. To target GFP expression specifically to the olfactory bulb, a plasmid with the coding sequence of GFP under control of multiple Gal4 binding sites (UAS) was electroporated into the anterior end of the forebrain at 24-28 hours post-fertilization (hpf). Although this method incorporates plasmid DNA into multiple regions of the forebrain, GFP expression is only induced in cells transgenically expressing the KalTA4 transcription factor. Thus, by using the GA080_9 transgenic line, this approach led to GFP expression exclusively in the developing olfactory bulb. GFP expressing cells targeted through this approach showed typical axonal projections, as previously described for mitral cells of the olfactory bulb 10. This method could also be used for targeted delivery of other reagents including short-hairpin RNA interference expression plasmids, which would provide a method for spatially and temporally discrete loss-of-function analysis.

The temporal and spatial resolution of genetic manipulations determines the spectrum of biological phenomena that they can perturb. Here we use temporally and spatially discrete in vivo electroporation, combined with transgenic lines of zebrafish, to induce expression of a GFP transgene specifically in neurons of the developing olfactory bulb.

In vivo electroporation is a powerful method for delivering DNA expression plasmids, RNAi reagents, and morpholino anti-sense oligonucleotides to specific ...

In the brain, sensory stimulation activates distributed populations of neurons among functional modules which participate to the coding of the stimulus. Functional optical imaging techniques are advantageous to visualize the activation of these modules in sensory cortices with high spatial resolution. In this context, endogenous optical signals that arise from molecular mechanisms linked to neuroenergetics are valuable sources of contrast to record spatial maps of sensory stimuli over wide fields in the rodent brain.
Here, we present two techniques based on changes of endogenous optical properties of the brain tissue during activation. First the intrinsic optical signals (IOS) are produced by a local alteration in red light reflectance due to: (i) absorption by changes in blood oxygenation level and blood volume (ii) photon scattering. The use of in vivo IOS to record spatial maps started in the mid 1980's with the observation of optical maps of whisker barrels in the rat and the orientation columns in the cat visual cortex1. IOS imaging of the surface of the rodent main olfactory bulb (OB) in response to odorants was later demonstrated by Larry Katz's group2. The second approach relies on flavoprotein autofluorescence signals (FAS) due to changes in the redox state of these mitochondrial metabolic intermediates. More precisely, the technique is based on the green fluorescence due to oxidized state of flavoproteins when the tissue is excited with blue light. Although such signals were probably among the first fluorescent molecules recorded for the study of brain activity by the pioneer studies of Britton Chances and colleagues3, it was not until recently that they have been used for mapping of brain activation in vivo. FAS imaging was first applied to the somatosensory cortex in rodents in response to hindpaw stimulation by Katsuei Shibuki's group4.
The olfactory system is of central importance for the survival of the vast majority of living species because it allows efficient detection and identification of chemical substances in the environment (food, predators). The OB is the first relay of olfactory information processing in the brain. It receives afferent projections from the olfactory primary sensory neurons that detect volatile odorant molecules. Each sensory neuron expresses only one type of odorant receptor and neurons carrying the same type of receptor send their nerve processes to the same well-defined microregions of &tilde;100&mu;m3 constituted of discrete neuropil, the olfactory glomerulus (Fig. 1). In the last decade, IOS imaging has fostered the functional exploration of the OB5, 6, 7 which has become one of the most studied sensory structures. The mapping of OB activity with FAS imaging has not been performed yet.
Here, we show the successive steps of an efficient protocol for IOS and FAS imaging to map odor-evoked activities in the mouse OB.

This article presents the protocols of intrinsic optical signals and flavoproteins autofluorescence signals imaging to map odor-evoked activities at the surface of the olfactory bulb in mice.

In the brain, sensory stimulation activates distributed populations of neurons among functional modules which participate to the coding of the stimulus. ...

The vomeronasal organ (VNO) detects chemosensory signals that carry information about the social, sexual and reproductive status of the individuals within the same species 1,2. These intraspecies signals, the pheromones, as well as signals from some predators 3, activate the vomeronasal sensory neurons (VSNs) with high levels of specificity and sensitivity 4. At least three distinct families of G-protein coupled receptors, V1R, V2R and FPR 5-14, are expressed in VNO neurons to mediate the detection of the chemosensory cues. To understand how pheromone information is encoded by the VNO, it is critical to analyze the response profiles of individual VSNs to various stimuli and identify the specific receptors that mediate these responses.
The neuroepithelia of VNO are enclosed in a pair of vomer bones. The semi-blind tubular structure of VNO has one open end (the vomeronasal duct) connecting to the nasal cavity. VSNs extend their dendrites to the lumen part of the VNO, where the pheromone cues are in contact with the receptors expressed at the dendritic knobs. The cell bodies of the VSNs form pseudo-stratified layers with V1R and V2R expressed in the apical and basal layers respectively 6-8. Several techniques have been utilized to monitor responses of VSNs to sensory stimuli 4,12,15-19. Among these techniques, acute slice preparation offers several advantages. First, compared to dissociated VSNs 3,17, slice preparations maintain the neurons in their native morphology and the dendrites of the cells stay relatively intact. Second, the cell bodies of the VSNs are easily accessible in coronal slice of the VNO to allow electrophysiology studies and imaging experiments as compared to whole epithelium and whole-mount preparations 12,20. Third, this method can be combined with molecular cloning techniques to allow receptor identification.
Sensory stimulation elicits strong Ca2+ influx in VSNs that is indicative of receptor activation 4,21. We thus develop transgenic mice that express G-CaMP2 in the olfactory sensory neurons, including the VSNs 15,22. The sensitivity and the genetic nature of the probe greatly facilitate Ca2+ imaging experiments. This method has eliminated the dye loading process used in previous studies 4,21. We also employ a ligand delivery system that enables application of various stimuli to the VNO slices. The combination of the two techniques allows us to monitor multiple neurons simultaneously in response to large numbers of stimuli. Finally, we have established a semi-automated analysis pipeline to assist image processing.

The vomeronasal organ (VNO) detects intraspecies chemical signals that convey social and reproductive information. We have performed Ca2+ imaging experiments using transgenic mice expressing G-CaMP2 in VNO tissue. This approach allows us to analyze the complicated response patterns of the vomeronasal neurons to large numbers of pheromone stimuli.

The vomeronasal organ (VNO) detects chemosensory signals that carry information about the social, sexual and reproductive status of the individuals within ...

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of the olfactory epithelium continuously give rise to new sensory neurons that extend their axons into the olfactory bulb, where they face the challenge to integrate into existing circuitry. Because of this particular feature, the olfactory system represents a unique opportunity to monitor axonal wiring and guidance, and to investigate synapse formation. Here we describe a procedure for in vivo labeling of sensory neurons and subsequent visualization of axons in the olfactory system of larvae of the amphibian Xenopus laevis. To stain sensory neurons in the olfactory organ we adopt the electroporation technique. In vivo electroporation is an established technique for delivering fluorophore-coupled dextrans or other macromolecules into living cells. Stained sensory neurons and their axonal processes can then be monitored in the living animal either using confocal laser-scanning or multiphoton microscopy. By reducing the number of labeled cells to few or single cells per animal, single axons can be tracked into the olfactory bulb and their morphological changes can be monitored over weeks by conducting series of in vivo time lapse imaging experiments. While the described protocol exemplifies the labeling and monitoring of olfactory sensory neurons, it can also be adopted to other cell types within the olfactory and other systems.

We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over time.

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of ...

The olfactory system, specialized in the detection, integration and processing of chemical molecules is likely the most thoroughly studied sensory system. However, there is piling evidence that olfaction is not solely limited to chemical sensitivity, but also includes temperature sensitivity. Premetamorphic Xenopus laevis are translucent animals, with protruding nasal cavities deprived of the cribriform plate separating the nose and the olfactory bulb. These characteristics make them well suited for studying olfaction, and particularly thermosensitivity. The present article describes the complete procedure for measuring temperature responses in the olfactory bulb of X. laevis larvae. Firstly, the electroporation of olfactory receptor neurons (ORNs) is performed with spectrally distinct dyes loaded into the nasal cavities in order to stain their axon terminals in the bulbar neuropil. The differential staining between left and right receptor neurons serves to identify the &#947;-glomerulus as the only structure innervated by contralateral presynaptic afferents. Secondly, the electroporation is combined with focal bolus loading in the olfactory bulb in order to stain mitral cells and their dendrites. The 3D brain volume is then scanned under line-illumination microscopy for the acquisition of fast calcium imaging data while small temperature drops are induced at the olfactory epithelium. Lastly, the post-acquisition analysis allows the morphological reconstruction of the thermosensitive network comprising the &#947;-glomerulus and its innervating mitral cells, based on specific temperature-induced Ca2+ traces. Using chemical odorants as stimuli in addition to temperature jumps enables the comparison between thermosensitive and chemosensitive networks in the olfactory bulb.

Here we describe a protocol for measuring and analyzing temperature responses in the olfactory bulb of Xenopus laevis. Olfactory receptor neurons and mitral cells are differentially stained, after which calcium changes are recorded, reflecting a sensitivity of some neural networks in the bulb to temperature drops induced at the nose.

The olfactory system, specialized in the detection, integration and processing of chemical molecules is likely the most thoroughly studied sensory system. ...

In most mammals, the vomeronasal organ (VNO) is a chemosensory structure that detects both hetero- and conspecific social cues. Vomeronasal sensory neurons (VSNs) express a specific type of G protein-coupled receptor (GPCR) from at least three different chemoreceptor gene families allowing sensitive and specific detection of chemosensory cues. These families comprise the V1r and V2r gene families as well as the formyl peptide receptor (FPR)-related sequence (Fpr-rs) family of putative chemoreceptor genes. In order to understand the physiology of vomeronasal receptor-ligand interactions and downstream signaling, it is essential to identify the biophysical properties inherent to each specific class of VSNs.
The physiological approach described here allows identification and in-depth analysis of a defined population of sensory neurons using a transgenic mouse line (Fpr-rs3-i-Venus). The use of this protocol, however, is not restricted to this specific line and thus can easily be extended to other genetically modified lines or wild type animals.

Here, we describe a physiological approach that allows identification and in-depth analysis of a defined population of sensory neurons in acute coronal tissue slices of the mouse vomeronasal organ using whole-cell patch-clamp recordings.

In most mammals, the vomeronasal organ (VNO) is a chemosensory structure that detects both hetero- and conspecific social cues. Vomeronasal sensory ...

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 ...

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. This work describes the preparation of rat sciatic nerves for ex vivo neurophysiology, including buffer preparation, animal procedures, equipment setup and neurophysiological recording. This work provides an overview of the different types of experiments possible with this method. The outlined method aims to provide 6 h of stimulation and recording on extracted peripheral nerve tissue in tightly controlled conditions for optimal consistency in results. Results obtained using this method are A-fibre compound action potentials (CAP) with peak-to-peak amplitudes in the millivolt range over the entire duration of the experiment. CAP amplitudes and shapes are consistent and reliable, making them useful to test and compare new electrodes to existing models, or the effects of interventions on the tissue, such as the use of chemicals, surgical alterations, or neuromodulatory stimulation techniques. Both conventional commercially available cuff electrodes with platinum-iridium contacts and custom-made conductive elastomer electrodes were tested and gave similar results in terms of nerve stimulus strength-duration response.

Preparation of Rat Sciatic Nerve for Ex Vivo Neurophysiology

This protocol describes the preparation of rat whole sciatic nerve tissue for ex vivo electrophysiological stimulation and recording in an environmentally-regulated, two-compartment, perfused saline bath.

Ex vivo preparations enable the study of many neurophysiological processes in isolation from the rest of the body while preserving local tissue structure. ...