Name: in-depth physiological analysis of defined cell populations in acute tissue slices of the mouse vomeronasal organ
Uploaded: 2016-09-10T14:00:00
Description: Watch this Scientific Journal Video about In-depth Physiological Analysis of Defined Cell Populations in Acute Tissue Slices of the Mouse Vomeronasal Organ at JoVE.com

We thank Ivan Rodriguez and Benoit von der Weid for generating the FPR-rs3-i-venus mouse line, their constructive criticism and fruitful discussions. This work was funded by grants of the Volkswagen Foundation (I/83533), the Deutsche Forschungsgemeinschaft (SP724/6-1) and by the Excellence Initiative of the German federal and state governments. MS is a Lichtenberg Professor of the Volkswagen Foundation.

All animal procedures were in compliance with local and European Union legislation on the protection of animals used for experimental purposes (Directive 86/609/EEC) and with recommendations put forward by the Federation of European Laboratory Animal Science Associations (FELASA). Both C57BL/6 mice and Fpr-rs3-i-Venus mice were housed in groups of both sexes at room temperature on a 12 hr light/dark cycle with food and water available ad libitum. For experiments young adults (6-20 weeks) of either sex were used....

The VNO is a chemosensory structure that detects semiochemicals. To date, the majority of vomeronasal receptors remains to be deorphanized as only few receptor-ligand pairs have been identified. Among those, V1rb2 was described to be specifically activated by the male urinary pheromone 2-heptanone30, V2rp5 to be activated by the male specific pheromone ESP157 as well as V2r1b and V2rf2 to be activated by the MHC peptides SYFPEITHI48 and SEIDLILGY58, respectively. A prerequisite...

Most animals rely heavily on their chemical senses to interact with their surroundings. The sense of smell plays an essential role for finding and evaluating food, avoiding predators and locating suitable mating partners. In most mammals, the olfactory system consists of at least four anatomically and functionally distinct peripheral subsystems: the main olfactory epithelium1,2, the Grueneberg ganglion3,4, the septal organ of Masera5,6 and the vomeronasal organ. The VNO comprises the peripheral sensory structure of the accessory olfactory system (AOS), which plays a major role in detecting chemical cues that convey information about identity, gender, social rank and sexual state7-10. The VNO is located at the base of the nasal septum right above the palate. In mice, it is a bilateral blind-ending tube enclosed in a cartilaginous capsule11-13. The organ consists of both a crescent-shaped medial sensory epithelium that harbors the VSNs and of a non-sensory part on the lateral side. Between both epithelia lies a mucus-filled lumen which is connected to the nasal cavity via the narrow vomeronasal duct14. A large lateral blood vessel in the non-sensory tissue provides a vascular pumping mechanism to facilitate entry of relatively large, mostly non-volatile molecules such as peptides or small proteins into the VNO lumen through negative pressure15,16. The structural components of the VNO are present at birth and the organ reaches adult size shortly before puberty17. However, whether the rodent AOS is already functional in juveniles is still subject to debate18-20.
VSNs are distinguished by both their epithelial location and the type of receptor they express. VSNs show a bipolar morphology with an unmyelinated axon and a single apical dendrite that protrudes towards the lumen and ends in a microvillous dendritic knob. VSN axons fasciculate to form the vomeronasal nerve that leaves the cartilaginous capsule at the dorso-caudal end, ascends along the septum, passes the cribriform plate and projects to the accessory olfactory bulb (AOB)21,22. The vomeronasal sensory epithelium consists of two layers: the apical layer is located closer to the luminal side and harbors both V1R- and all but one type of FPR-rs-expressing neurons. These neurons coexpress the G-protein &#945;-subunit G&#945;i2 and project to the anterior part of the AOB23-25. Sensory neurons located in the more basal layer express V2Rs or FPR-rs1 alongside G&#945;o and send their axons to the posterior region of the AOB26-28.
Vomeronasal neurons are likely activated by rather small semiochemicals29-33 (V1Rs) or proteinaceous compounds34-38 (V2Rs) that are secreted into various bodily fluids such as urine, saliva and tear fluid37,39-41. In situ experiments have shown that VSNs are also activated by formylated peptides and various antimicrobial/inflammation-linked compounds25,42. Moreover, heterologously expressed FPR-rs proteins share agonist spectra with FPRs expressed in the immune system, indicating a potential role as detectors for sickness in conspecifics or spoiled food sources25 (see reference43).
Fundamental to understanding receptor-ligand relationships and downstream signaling cascades in specific VSN populations is a detailed evaluation of their basic biophysical characteristics in a native environment. In the past, the analysis of cellular signaling has greatly benefitted from genetically modified animals that mark a defined population of neurons by coexpressing a fluorescent marker protein30,44-49. In this protocol, a transgenic mouse line that expresses FPR-rs3 together with a fluorescent marker (Fpr-rs3-i-Venus) is used. This approach exemplifies how to employ such a genetically modified mouse strain to perform electrophysiological analysis of an optically identifiable cell population using single neuron patch-clamp recordings in acute coronal VNO tissue slices. An air pressure-driven multi-barrel perfusion system for sensory stimuli and pharmacological agents allows quick, reversible and focal neuronal stimulation or inhibition during recordings. Whole-cell recordings in slice preparations allow for a detailed analysis of intrinsic properties, voltage-activated conductances, as well as action potential discharge patterns in the cell&#39;s native environment.

<table border="0" cellpadding="0" cellspacing="0" width="846">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Chemicals</td>
			<td style="width:133px;"></td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Agarose (low-gelling temperature)</td>
			<td style="width:133px;">PeqLab</td>
			<td style="width:116px;">35-2030</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">ATP (Mg-ATP)</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">A9187</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES)</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">B9879</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Calcium chloride</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">C1016</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Ethylene glycol tetraacetic acid (EGTA)</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">E3889</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Glucose</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">G8270</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">GTP (Na-GTP)</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">51120</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">H3375</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Magnesium chloride</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">M8266</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Potassium chloride</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">P9333</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Potassium hydroxide</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">03564</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Sodium chloride</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">S7653</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Sodium hydrogen carbonate</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">S5761</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Sodium hydroxide</td>
			<td style="width:133px;">Sigma-Aldrich</td>
			<td style="width:116px;">S8045</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;"></td>
			<td style="width:133px;"></td>
			<td style="width:116px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Surgical tools and consumables</td>
			<td style="width:133px;"></td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Large petri dish, 90 mm</td>
			<td style="width:133px;">VWR</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">decapitation, dissection of VNO capsule</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Small petri dish, 35 mm</td>
			<td style="width:133px;">VWR</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">lid for VNO dissection, dish for embedding in agarose</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Sharp large surgical scissor</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">decapitation, removal of lower jaw</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Strong bone scissors</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">cutting incisors</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Medium forceps, Dumont tweezers #2</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">removing skin and palate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Micro spring scissors, 8.5 cm, curved, 7 mm blades&#160;</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">cutting out VNO&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Two pairs of fine forceps, Dumont tweezers #5</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">dissecting VNO out of cartilaginous capsule</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Small stainless steel spatula</td>
			<td style="width:133px;">Fine Science Tools</td>
			<td style="width:116px;"></td>
			<td style="width:275px;">handling agarose block and tissue slices</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Surgical scalpel</td>
			<td style="width:133px;"></td>
			<td style="width:116px;"></td>
			<td style="width:275px;">cutting agarose block into pyramidal shape</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Name</td>
			<td style="width:133px;">Company</td>
			<td style="width:116px;">Catalog Number</td>
			<td style="width:275px;">Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Equipment</td>
			<td style="width:133px;"></td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Amplifier</td>
			<td style="width:133px;">HEKA Elektronik</td>
			<td style="width:116px;">EPC-10</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Borosilicate glass capillaries (1.50 mm OD/0.86 mm ID)</td>
			<td style="width:133px;">Science Products</td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">CCD-camera</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">DFC360FX</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Filter cube, excitation: BP 450-490, suppression: LP 515</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">I3</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Fluorescence lamp</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">EL6000</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Hot plate magnetic stirrer</td>
			<td style="width:133px;">Snijders</td>
			<td style="width:116px;">34532</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Microforge&#160;</td>
			<td style="width:133px;">Narishige</td>
			<td style="width:116px;">MF-830</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Micromanipulator Device&#160;</td>
			<td style="width:133px;">Luigs &#38; Neumann</td>
			<td style="width:116px;">SM-5</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Micropipette puller, vertical two-step</td>
			<td style="width:133px;">Narishige</td>
			<td style="width:116px;">PC-10&#160;</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Microscope</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">CSM DM 6000 SP5</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Noise eliminator 50/60 Hz (HumBug)</td>
			<td style="width:133px;">Quest Scientific</td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Objective&#160;</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">HCX APO L20x/1.00 W</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Oscilloscope</td>
			<td style="width:133px;">Tektronik</td>
			<td style="width:116px;">TDS 1001B</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Osmometer&#160;</td>
			<td style="width:133px;">Gonotec</td>
			<td style="width:116px;">Osmomat 030</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Perfusion system 8-in-1</td>
			<td style="width:133px;">AutoMate Scientific</td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">pH Meter five easy</td>
			<td style="width:133px;">Mettler Toledo</td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Pipette storage jar</td>
			<td style="width:133px;">World Precision Instruments</td>
			<td style="width:116px;">e212</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Recording chamber&#160;</td>
			<td style="width:133px;">Luigs &#38; Neumann</td>
			<td style="width:116px;">Slice mini chamber</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:323px;">Razor blades</td>
			<td style="width:133px;">Wilkinson Sword GmbH</td>
			<td style="width:116px;">Wilkinson Sword Classic</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:323px;">Oxygenating slice storage chamber; alternative commercial chambers are e.g. BSK1 Brain Slice Keeper (Digitimer) or the Pre-chamber (BSC-PC; Warner Instruments)</td>
			<td style="width:133px;">custom-made</td>
			<td style="width:116px;"></td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Stereo microscope</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">S4E</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Trigger interface&#160;</td>
			<td style="width:133px;">HEKA Elektronik</td>
			<td style="width:116px;">TIB-14 S</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Vibratome&#160;</td>
			<td style="width:133px;">Leica Microsystems</td>
			<td style="width:116px;">VT 1000 S</td>
			<td style="width:275px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:323px;">Water bath&#160;</td>
			<td style="width:133px;">Memmert</td>
			<td style="width:116px;">WNB 45</td>
			<td style="width:275px;"></td>
		</tr>
	</tbody>
</table>

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

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.

To gain insight into the biophysical and physiological properties of defined cell populations, we perform acute coronal tissue slices of the mouse VNO (Figure 1-2). After dissection, slices can be kept in ice-cold oxygenated extracellular solution (S2) for several hr. At the recording setup, a constant exchange with fresh oxygenated solution (Figure 2D) ensures tissue viability throughout the experiment. We here employ a transg...

Watch this Scientific Journal Video about In-depth Physiological Analysis of Defined Cell Populations in Acute Tissue Slices of the Mouse Vomeronasal Organ at JoVE.com

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.

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

Research

JoVE Journal

Neuroscience

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. ...

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

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

Time-lapse Imaging of Neuroblast Migration in Acute Slices of the Adult Mouse Forebrain

There is a substantial body of evidence indicating that new functional neurons are constitutively generated from an endogenous pool of neural stem cells ...

Preparation of Acute Subventricular Zone Slices for Calcium Imaging

The subventricular zone (SVZ) is one of the two neurogenic zones in the postnatal brain. The SVZ contains densely packed cells, including neural ...

Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs ...

In vivo Postnatal Electroporation and Time-lapse Imaging of Neuroblast Migration in Mouse Acute Brain Slices

In vivo Postnatal Electroporation and Time-lapse Imaging of Neuroblast Migration in Mouse Acute Brain Slices

The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal brain. Here, neural progenitors proliferate and give rise to ...

Functional Analysis of the Larval Feeding Circuit in Drosophila

Functional Analysis of the Larval Feeding Circuit in Drosophila

The serotonergic  feeding circuit in Drosophila  melanogaster larvae can be used to investigate neuronal substrates of  critical importance during the ...

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

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 ...

Slice It Hot: Acute Adult Brain Slicing in Physiological Temperature

Here we present a protocol for preparation of acute brain slices. This procedure is a critical element for electrophysiological patch-clamp experiments ...

Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method

Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method

This protocol is a practical guide to the N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. Numerous recent studies have ...