The authors thank S. Tausch for excellent technical assistance. The work was supported by BMBF (Bernstein Focus 01GQ0923) and DFG (FOR1738).

NOTE: All procedures involving living animals were carried out in accordance with the EC directive 86/609/EEC guidelines on the care and use of laboratory animals and approved by the local ethics committee (Th&#252;ringer Landesamt f&#252;r Lebensmittelsicherheit und Verbraucherschutz).
1. Intraperitoneal Injection of Thymidine Analogs
<ol>
	<li>Weigh animals the day before injection. Calculate the amount of thymidine analog required for all injections planned on the next day as well as individual weight-adjusted injection volumes of a 10 mg/ml stock solution.</li>
	<li>Prepare 10 mg/ml thymidine stock solution.&#160;(CAUTION! Thymidine analogs are toxic. Follow the specific Material Safety Data Sheets (MSDS) provided by the suppliers, i.e., wear lab coat and gloves, use a chemical fume hood).
	<ol>
		<li>Take thymidine analog from the freezer and bring it to RT,&#160;approx. 21 &#176;C. Weigh 10 mg and add sterile saline (for BrdU and CldU) or 0.04 N NaOH (in sterile saline; for IdU), vortex. Place for at least 10 - 15 min in a 50 &#176;C water bath and vortex every 2 - 3 min to dissolve the powder. 
		NOTE: Use solutions for up to 24 hr when stored at RT and for several weeks at -20 &#176;C. Protect solutions from light (cover with aluminum foil). Always check for precipitates and re-dissolve if necessary.</li>
	</ol>
	</li>
	<li>Restrain the mouse by the scruff and intraperitoneally inject an appropriate, weight-adjusted volume of stock solution (at RT) using a fine dosage syringe with a 30 G needle. 
	NOTE: In case CldU and IdU have to be administered sequentially within the same animal, consider to inject equimolar concentrations (e.g., 42.5 mg/kg CldU and 57.5 mg/kg IdU, which correspond to 50 mg/kg BrdU). Therefore, adjust the injection volumes of the 10 mg/ml stock solutions accordingly.</li>
</ol>
2. Tissue Preparation
<ol>
	<li>Prepare 4% formaldehyde in 0.1 M phosphate buffer pH 7.4 on the day before perfusion. Store at 4 &#176;C.</li>
	<li>Transcardially perfuse the deeply anesthetized mice (3.5% isoflurane) via the left ventricle with 10 ml ice-cold PBS, then with 40 ml ice-cold formaldehyde (flow rate 5 ml/min). Dissect the brain and post-fix in the same fixative for 24 hr at 4&#176;C.</li>
	<li>Transfer the brains consecutively into 10% (24 hr at 4&#176;C) and 30% sucrose (until the brain sinks, approx. 48 hr). For freezing, slowly submerge the cryoprotected brains into -25 &#176;C isopentane until no bubbles emerge from the tissue. Store at -80 &#176;C.</li>
	<li>Cut coronal sections of 40 &#181;m thickness on a freezing microtome (block temperature at -25 to -16 &#176;C). Sequentially transfer sections into antifreeze solution containing wells of a 24-well cell culture plate (see Figure 1). Store at -20 &#176;C.</li>
</ol>
<img alt="Figure 1" src="/files/ftp_upload/52551/52551fig1.jpg" /> 
Figure 1. Schematic illustration of transferring microtome slices into a 24-well plate. Start at A1 and place subsequent slices into row A, after A6 go to the next row B and so forth. When reaching D6, go back to A1 and continue. This arrangement of slices allows for quantification of every nth section of an entire brain. For quantification of newborn cells take every 6th brain section (equivalent to the content of one column), for immunofluorescence phenotyping take every 12th section (equivalent to the content of 2 alternating rows of one column).
3. Immunostaining
NOTE: Sections are processed free floating, usually in 6-well plates equipped with a carrier plate and mesh inserts. As an exception, blocking, antibody incubations and ABC reaction are done in 12- or 24-well plates without mesh inserts (0.5 to 1 ml per well is sufficient, depending on the number of slices that have to be stained). During these steps, transfer sections with the help of a fine brush (rinse with each new solution). All incubations are done with continuous agitation (max 150 rpm).
<ol>
	<li>Immunohistochemistry (ABC method)
	<ol>
		<li>Transfer sections from antifreeze into TBS and rinse thoroughly (once O/N&#160;at 4 &#176;C, 5 times at RT for 10 min each) to completely remove antifreeze.</li>
		<li>Incubate for 30 min in 1.5% H2O2 in TBS-T to quench endogenous peroxidase activity. Pay attention to bubbling and re-submerge sections if necessary. Rinse 3 times in TBS for 15 min each.</li>
		<li>Optional: Meanwhile preheat a heating cabinet and 2 N HCl to 37 &#176;C. Incubate sections for 30 min at 37 &#176;C in 2 N HCl to denature DNA. Gently separate sections with the help of a brush.</li>
		<li>Optional: Neutralize sections for 10 min in 0.1 M borate buffer pH 8.5, RT. While transferring, briefly swab the mesh inserts containing the sections on a paper towel to remove HCl leavings. Rinse 2 times in TBS for 15 min each.</li>
		<li>Incubate in TBSplus to permeabilize the tissue and to block unspecific antibody binding sites, 1 hr at RT.</li>
		<li>Incubate in primary antibody diluted in TBSplus, O/N at 4 &#176;C. Rinse 3 times in TBS for 15 min each.</li>
		<li>Incubate in biotinylated secondary antibody diluted in TBSplus, 3 hr at RT. Rinse 3 times in TBS for 15 min each. Meanwhile...</li>
		<li>Prepare ABC complex according to manufacturer&#39;s protocol (1% A + 1% B in TBS-T). Allow to stand for 30 min at RT before use. Incubate sections in AB reagent for 1 hr at RT. Rinse 3 times in TBS for 15 min each.</li>
		<li>Prepare 50 ml 0.5 mg/ml DAB in TBS-T per 6- or 12-well plate, split into two halves and pipette 4 ml or 2 ml per well, respectively. Transfer sections into DAB solution (CAUTION! DAB is toxic. Follow the specific MSDS provided by the supplier, i.e., wear lab coat and gloves, use a chemical fume hood).</li>
		<li>Add 0.5 ml 1% H2O2 to the remaining 25 ml DAB solution, mix and pipette equivalent volumes as above to each well to start peroxidase reaction. Incubate for 12 min. Rinse 3 times in TBS for 15 min each.</li>
		<li>Mount sections to slides in gelatin, air dry O/N. Coverslip with permanent mounting medium.</li>
		<li>Optional: Counterstain before placing the coverslip (see section 3.5). 
		NOTE: If the signal-to-noise ratio is low because of high background, repeat H2O2 treatment after the incubation with AB reagent (step 3.1.8).</li>
	</ol>
	</li>
	<li>Multiple-immunofluorescence
	<ol>
		<li>Single or simultaneous multiple immunofluorescence
		<ol>
			<li>Transfer sections from antifreeze into TBS and rinse thoroughly (once O/N at 4 &#176;C, 5 times at RT for 10 min each) to completely remove antifreeze.</li>
			<li>Optional: as steps 3.1.3 - 3.1.4.</li>
			<li>Incubate in TBSplus to permeabilize the tissue and block unspecific antibody binding sites, 1 hr at RT.</li>
			<li>Incubate in primary antibody cocktail (e.g., rat &#945;-BrdU, guinea pig &#945;-DCX, goat &#945;-GFP) diluted in TBSplus, O/N at 4&#176;C. Rinse 3 times in TBS for 15 min each.</li>
			<li>Incubate in cocktail of fluorochrome-conjugated secondary antibodies (e.g., Rhodamine Red &#945;-rat, Alexa-647 &#945;-guinea pig, Alexa-488 &#945;-goat; all derived in donkey) diluted in TBSplus, 3 hr at RT or O/N at 4 &#176;C. From now on protect sections from light. Rinse 3 times in TBS for 15 min each.</li>
			<li>Mount sections to slides in gelatin, air dry O/N. Coverslip with aqueous mounting medium.</li>
		</ol>
		</li>
		<li>Sequential multiple immunofluorescence with primary antibodies from same host species
		<ol>
			<li>As steps 3.2.1.1 - 3.2.1.3.</li>
			<li>Incubate in first primary antibody (e.g., rabbit &#945;-antigen A), O/N at 4 &#176;C. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in first fluorochrome-conjugated secondary antibody (e.g., Rhodamine Red-conj. donkey &#945;-rabbit), 3 hr RT. From now on protect sections from light. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in 10% normal serum from same host as the primary antibodies (e.g., rabbit serum) for 3 hr RT to saturate open paratopes on the first secondary antibody. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in TBSplus with 50 &#181;g/ml unconjugated monovalent Fab fragments directed against the host of the primary antibodies (e.g., &#945;-rabbit IgG (H+L)) to cover epitopes that could be recognized by the second secondary antibody, O/N at 4 &#176;C.</li>
			<li>Rinse at least 3 times in TBS and once in TBS-T for 10 min each. While transferring, briefly swab the mesh inserts containing the sections on a paper towel to remove any Fab leavings.</li>
			<li>Incubate in second primary antibody (e.g., rabbit &#945;-antigen B), O/N at 4 &#176;C. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in second fluorochrome-conjugated secondary antibody (e.g., Alexa-488-conj. donkey &#945;-rabbit), 3 hr RT. Rinse 3 times in TBS for 15 min each, mount and coverslip as above. 
			NOTE: To label antigens with antibodies from different host species add them to step 3.2.2.2 and the respective secondary antibodies to step 3.2.2.3.</li>
		</ol>
		</li>
		<li>One of the secondary antibodies from same species as one of the primary antibodies 
		NOTE: This protocol is suitable for quadruple-staining against BrdU or Ki67 together with GFAP, nestin-GFP and DCX.
		<ol>
			<li>Follow strictly protocol steps 3.2.1.1 - 3.2.1.5. Until this point use only donkey serum in TBSplus.</li>
			<li>Incubate in TBSplus containing 3% goat serum for 1 hr at RT. This covers open paratopes on the &#945;-goat secondary antibody. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in AMCA-conj. goat &#945;-rabbit diluted in TBSplus, 3 hr RT or O/N 4 &#176;C. Rinse three times in TBS for 15 min each, mount and coverslip as above.</li>
		</ol>
		</li>
		<li>CldU, IdU co-staining
		<ol>
			<li>Rinse, denature and neutralize sections as described in section 3.2.1 (steps 3.2.1.1 - 3.2.1.2).</li>
			<li>Incubate with 20 &#181;g/ml unconjugated Fab fragments &#945;-mouse IgG (H+L) in TBSplus, 1 hr at RT. Rinse 4 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in primary antibody cocktail containing rat &#945;-BrdU (1:400; purified IgG2) and mouse &#945;-BrdU (1:350) diluted in TBSplus, O/N at 4&#176;C. Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in secondary antibody cocktail containing biotinylated donkey &#945;-rat (1:500) and FITC-conj. donkey &#945;-mouse Fab fragments (1:100). Rinse 3 times in TBS and once in TBS-T for 10 min each.</li>
			<li>Incubate in Rhodamine Red-conj. Streptavidin, 2 hr at RT. Rinse 3 times in TBS for 15 min each, mount and coverslip as above.</li>
		</ol>
		</li>
		<li>Amplification of fluorescence signal in nestin-GFP mice
		<ol>
			<li>Add goat &#945;-GFP to the primary antibody cocktail.</li>
			<li>Add a fluorochrome conjugated secondary antibody with spectral properties similar to GFP (such as Alexa 488 conj. donkey &#945;-goat) to the secondary antibody cocktail.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Epitope retrieval
	<ol>
		<li>Carry out epitope retrieval after rinsing out antifreeze. Preheat steamer with 6- or 12-well plates containing 0.1 M citrate buffer pH 6.0 to 95 - 99 &#176;C (approximately 25 min).</li>
		<li>Transfer the sections into the hot citrate buffer and steam for 30 min (cover the plates with aluminum foil as plastic lids are not heat-resistant).</li>
		<li>Immediately place the plates in an ice bath to cool down. This helps to protect tissue morphology, which is of particular importance when working with brain sections of postnatal animals.</li>
		<li>Rinse 3 times in TBS for 10 min each to rinse out and neutralize the citrate and continue staining.</li>
	</ol>
	</li>
	<li>Mouse antibodies on mouse tissue
	<ol>
		<li>Add 20 &#181;g/ml monovalent Fab fragments &#945;-mouse IgG (H+L; same host-species than secondary antibody) to the first blocking step (e.g., step 3.1.5 or 3.2.1.3).</li>
		<li>Rinse 4 times in TBS and once in TBS-T for 10 min each, and proceed with respective protocol.</li>
	</ol>
	</li>
	<li>Cresyl violet counterstaining
	<ol>
		<li>Preheat cresyl violet solution to 60 &#176;C (in glass jar). Incubate slides in the hot solution for 3 min.</li>
		<li>Rinse in aq. dest. and dehydrate 2 times for 1 min each in 70%, 96% and 100% isopropanol.</li>
		<li>Clear for 5 - 6 min in xylene or a xylene substitute and coverslip with a compatible permanent mounting medium.</li>
	</ol>
	</li>
</ol>
4. Data Analysis
<ol>
	<li>Count peroxidase stained newborn cells in every 6th section along the entire rostrocaudal extent of the dentate gyrus. Use a light microscope at 400X&#160;magnification.</li>
	<li>Multiply the resulting cell numbers with the intersection interval to obtain an estimate of total numbers of newborn cells.</li>
	<li>Image the fluorescence labeled sections with a confocal laser microscope equipped with appropriate lasers and filter systems. Take image stacks at random positions along the entire extent of the dentate gyrus at 400X magnification and analyze at least 50 randomly selected cells of interest per hemisphere for co-labeling with other markers.</li>
	<li>Multiply the resulting percentages of co-labeled cells (%/100) with the total numbers of newborn cells to calculate absolute numbers of specific newborn cell populations.</li>
</ol>

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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+doses+of+bromo-+and+iododeoxyuridine+produce+near-saturation+labeling+of+adult+proliferative+populations+in+the+dentate+gyrus.">Low doses of bromo- and iododeoxyuridine produce near-saturation labeling of adult proliferative populations in the dentate gyrus.</a> Eur J Neurosci. 21 (3), 803-807 (2005).</li><li>Cameron, H. A., McKay, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+neurogenesis+produces+a+large+pool+of+new+granule+cells+in+the+dentate+gyrus.">Adult neurogenesis produces a large pool of new granule cells in the dentate gyrus.</a> J Comp Neurol. 435 (4), 406-417 (2001).</li><li>Vega, C. J., Peterson, D. 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The authors declare that they have no competing financial interests.

Quantification and identification of subpopulations of newborn cells is a central issue in adult neurogenesis research. Combining proliferation markers and antibodies against proteins expressed during specific stages of adult neurogenesis allows immunohistochemical detection of these subpopulations. Some of the antibodies or antibody combinations require specific staining conditions.
Labeling of dividing cells with synthetic thymidine analogs is still the gold standard for studying adult hippo...

Two brain regions constitutively generate new neurons throughout life, the subventricular zone of the lateral ventricles and the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG). The newborn neurons derive from neural progenitor cells and go through different stages of morphological and physiological development before reaching maturity1,2. From a slowly dividing radial glia-like stem cell (type 1) consecutive stages of transit amplifying intermediate progenitor cells arise. The more undifferentiated subtypes (type 2a and type 2b) have an irregular shape with short, tangential processes. They generate neuroblasts (type 3) that gradually exit the cell cycle to become immature neurons (with dendrites extended towards the molecular layer) and finally integrate into the hippocampal network as mature granule cells. Due to their particular physiological characteristics these cells provide the circuitry with enhanced plasticity3 suggesting a unique role in hippocampal function. Actually, studies of the last decade generated substantial evidence that adult neurogenesis contributes to spatial memory, pattern separation and emotional behavior4,5.
Adult neurogenesis can be studied using different approaches. Thymidine analogs incorporate into DNA during the S-phase of the cell cycle and allow birth dating, quantification and fate analysis of newborn cells6-8. Sequential application of different thymidine analogs (e.g., CldU, EdU or IdU) can be used to study cell turnover or cell populations born at different time points during the course of an experiment9. An alternative, endogenous marker for cell proliferation is Ki67. It is expressed in dividing cells during all phases of the cell cycle (G1, S, G2, M) except the resting phase (G0) and the beginning of G1&#160;10,11. To analyze the phenotype of newborn cell populations in the adult dentate gyrus several stage-specific molecular markers can be used such as GFAP, nestin, DCX and NeuN1,6. GFAP is a marker of mature astrocytes but is also expressed in radial glia-like cells in the adult forebrain. Nestin is an intermediate filament specific for radial glia-like cells and early intermediate progenitor cells. DCX is a microtubule-associated protein expressed in intermediate progenitors, neuroblasts and immature neurons. Based on the (co-) expression of these three markers and the morphological features of the labeled cells four distinct progenitor cell subtypes can be identified: type 1 (GFAP+, nestin+, DCX-), type 2a (GFAP-, nestin+, DCX-), type 2b (GFAP-, nestin+, DCX+) and type 3 (GFAP-,nestin-, DCX+)1. Co-labeling of DCX together with NeuN, which is expressed in postmitotic neurons, allows the differentiation of immature (DCX+, NeuN+) and mature (DCX-, NeuN+) granule neurons.
The above mentioned markers are frequently used for immunofluorescent co-labeling and subsequent confocal microscopy to analyze the number and identity of newborn cells. This typically requires antibodies from different host species to prevent undesired antibody cross-reactivity. However, the majority of primary antibodies suitable for neurogenesis research are raised either in rabbits or mice (e.g., mouse &#945;-BrdU, mouse &#945;-NeuN, rabbit &#945;-Ki67, rabbit &#945;-GFAP). This leads to serious limitations in the number and combination of antigens that could be evaluated in a single slice. This in turn not only increases the staining effort, as multiple stainings have to be performed, but might also compromise the reliability of results. Furthermore, some antigens are susceptible to formalin fixation-induced epitope masking (e.g., Ki67, nestin). We herein describe modifications from the classical single- and multiple immunolabeling protocols (e.g., epitope retrieval, multiple sequential immunostaining, use of nestin-GFP transgenic mice12) that overcome many of these issues. In particular, the sequential multiple immunofluorescence protocol allows staining against up to four different antigens even if part of the antibodies is derived from the same host. This enables the simultaneous detection of type 1, type 2a, type 2b and type 3 progenitor cells, as well as their proliferative activity within a single section.

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		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thymidine analog administration</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5-Bromo-2&#8242;-deoxyuridine, BrdU</td>
			<td>Sigma-Aldrich</td>
			<td>B9285</td>
			<td rowspan="4" style="width:131px;">toxic (mutagenic, teratogenic)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5-Chloro-2&#8242;-deoxyuridine, CldU</td>
			<td>Sigma-Aldrich</td>
			<td>C6891</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5-Chloro-2&#8242;-deoxyuridine, CldU</td>
			<td>MP Biomedicals</td>
			<td>2105478</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5-Iodo-2&#8242;-deoxyuridine, IdU</td>
			<td>MP Biomedicals</td>
			<td>2100357</td>
		</tr>
		<tr height="10">
			<td height="10" style="height:11px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tissue preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isoflurane-Actavis</td>
			<td>Piramal Healthcare</td>
			<td>700211</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Paraformaldehyde powder (PFA)</td>
			<td>Riedel-De H&#228;en</td>
			<td>16005</td>
			<td>toxic, flammable</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Perfusion pump PD5206</td>
			<td>Heidolph Instruments</td>
			<td>523-52060-00</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Masterflex Tygon lab tubing, &#216; 0.8 mm&#160;</td>
			<td>Thermo Fischer Scientific</td>
			<td>06409-13</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Feeding needle, straight, 21G, 1.75mm olive tip, 40mm</td>
			<td>Agnthos</td>
			<td>1036</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Freezing microtome Microm HM 400</td>
			<td>Thermo Fischer Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">24 Well Cell Culture Multiwell Plates</td>
			<td style="width:147px;">Greiner Bio-One</td>
			<td>662160</td>
			<td></td>
		</tr>
		<tr height="10">
			<td height="10" style="height:11px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Immunohistochemistry</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tefal Vitacuisine Steamer</td>
			<td>Tefal</td>
			<td>VS 4001</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Netwell 24mm Polyester Mesh Membrane Inserts Pre-Loaded in 6-Well Culture Plates</td>
			<td>Corning</td>
			<td>3479</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Netwell 15mm Polyester Mesh Membrane Inserts Pre-Loaded in 12-Well Culture Plates</td>
			<td>Corning</td>
			<td>3477</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Netwell Plastic 6-Well Carrier Kit for 24mm Polyester Mesh Membrane Inserts</td>
			<td>Corning</td>
			<td>3521</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Netwell Plastic 12-Well Carrier Kit for 15mm Polyester Mesh Membrane Inserts</td>
			<td>Corning</td>
			<td>3520</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Vectastain Elite ABC Kit</td>
			<td>Vector Laboratories</td>
			<td>PK-6100</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">DAB (3,3&#8242;-Diaminobenzidine tetrahydrochloride hydrate)</td>
			<td>Sigma-Aldrich</td>
			<td>D-5637</td>
			<td style="width:131px;">carcinogenic, light sensitive</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Fluoromount-G</td>
			<td>SouthernBiotech</td>
			<td>0100-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Primary antibodies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="48">
			<td height="48" style="height:48px;">rabbit IgG1 &#945;-Ki67</td>
			<td style="width:147px;">Novocastra/ Leica Biosystems</td>
			<td>NCL-L-Ki67MM1</td>
			<td style="width:131px;">DAB 1:400/IF 1:100; requires epitope retrieval</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">rabbit &#945;-GFAP, AS-3-GF</td>
			<td>Synaptic Systems</td>
			<td>173 002</td>
			<td>1:500</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">goat IgG (H+L) &#945;-GFP</td>
			<td>Acris Antibodies</td>
			<td>R1091P</td>
			<td>1:300</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;">mouse IgG1 &#945;-nestin</td>
			<td>Abcam</td>
			<td>ab6142</td>
			<td style="width:131px;">1:200; requires epitope retrieval</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">guinea pig IgG (H+L) &#945;-Doublecortin</td>
			<td>Merck Millipore</td>
			<td>AB2253</td>
			<td>1:500</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;">rat IgG2a &#945;-BrdU (ascites)</td>
			<td>AbD Serotec/ Bio-Rad</td>
			<td>OBT0030CX</td>
			<td style="width:131px;">for detection of BrdU; DAB 1:500/IF 1:400</td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;">rat IgG2a &#945;-BrdU (purified)</td>
			<td>AbD Serotec/ Bio-Rad</td>
			<td>OBT0030&#160;&#160;</td>
			<td style="width:131px;">for detection of CldU; DAB 1:500/IF 1:250-400</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;">mouse IgG1&#312; &#945;-BrdU</td>
			<td>BD Biosciences</td>
			<td>347580</td>
			<td style="width:131px;">for detection of IdU; DAB 1:500/IF 1:350</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">mouse IgG1 &#945;-NeuN</td>
			<td>Merck Millipore</td>
			<td>MAB377</td>
			<td>1:500</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Secondary antibodies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-guinea pig IgG (H+L)-Biotin</td>
			<td>Dianova</td>
			<td>711-065-152</td>
			<td>1:500</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-rat IgG (H+L)-Biotin</td>
			<td>Dianova</td>
			<td>712-065-150</td>
			<td>1:500</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-mouse IgG (H+L)-Biotin</td>
			<td>Dianova</td>
			<td>715-065-151</td>
			<td>1:500</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">goat &#945;-rat IgG (H+L)-Alexa Fluor 488</td>
			<td>Molecular Probes</td>
			<td>A11006</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-goat IgG (H+L)-Alexa Fluor 488</td>
			<td>Molecular Probes</td>
			<td>A11055</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-mouse IgG (H+L)-FITC, Fab-Fragment</td>
			<td>Dianova</td>
			<td>715-097-003</td>
			<td>1:100</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-mouse IgG (H+L)-Alexa Fluor 647</td>
			<td>Dianova</td>
			<td>715-605-151</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-guinea pig IgG (H+L)-Alexa Fluor 647</td>
			<td>Dianova</td>
			<td>706-605-148</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-rat IgG (H+L)-Rhodamine Red-X</td>
			<td>Dianova</td>
			<td>712-295-150</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">donkey &#945;-rabbit IgG (H+L)-Rhodamine Red-X</td>
			<td>Dianova</td>
			<td>711-295-152</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">donkey &#945;-guinea pig IgG (H+L)-Rhodamine Red-X</td>
			<td>Dianova</td>
			<td>706-296-148</td>
			<td>1:250</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Streptavidin-Rhodamine Red-X&#160;</td>
			<td>Dianova</td>
			<td>016-290-084</td>
			<td>1:500</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">goat &#945;-rabbit IgG (H+L)-AMCA</td>
			<td>Dianova</td>
			<td>111-155-144</td>
			<td style="width:131px;">1:250, works only with rabbit &#945;-GFAP</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hoechst 33342</td>
			<td>Molecular Probes</td>
			<td>H3570</td>
			<td>1:1000</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DAPI</td>
			<td>Molecular Probes</td>
			<td>D1306</td>
			<td>1:1000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Blocking</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fab-fragment donkey &#945;-mouse IgG (H+L)</td>
			<td>Dianova</td>
			<td>715-007-003</td>
			<td>1:20</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fab-fragment donkey &#945;-rabbit IgG (H+L)</td>
			<td>Dianova</td>
			<td>711-007-003</td>
			<td>1:20</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Normal donkey serum</td>
			<td>Merck Millipore</td>
			<td>S30</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Normal rabbit serum</td>
			<td>Dianova</td>
			<td>011-000-010</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Normal goat serum</td>
			<td>Dianova</td>
			<td>005-000-001</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bovine Serum Albumine</td>
			<td>Sigma-Aldrich</td>
			<td>A7906</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Histology</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Cresyl violett</td>
			<td>Sigma-Aldrich</td>
			<td>C5042</td>
			<td></td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Neo-Clear</td>
			<td>Merck Millipore</td>
			<td>109843</td>
			<td style="width:131px;">non-toxic xylene substitute</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:277px;">Neo-Mount</td>
			<td>Merck Millipore</td>
			<td>109016</td>
			<td style="width:131px;">permanent mounting medium</td>
		</tr>
		<tr height="10">
			<td height="10" style="height:11px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microscopy</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">Axioskop 2</td>
			<td>Carl Zeiss Microscopy</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:277px;">LSM 710</td>
			<td>Carl Zeiss Microscopy</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

immunohistochemistry and multiple labeling with antibodies from the same host species to study adult hippocampal neurogenesis

Adult neurogenesis is a highly regulated, multi-stage process in which new neurons are generated from an activated neural stem cell via increasingly committed intermediate progenitor subtypes. Each of these subtypes expresses a set of specific molecular markers that, together with specific morphological criteria, can be used for their identification. Typically, immunofluorescent techniques are applied involving subtype-specific antibodies in combination with exo- or endogenous proliferation markers. We herein describe immunolabeling methods for the detection and quantification of all stages of adult hippocampal neurogenesis. These comprise the application of thymidine analogs, transcardial perfusion, tissue processing, heat-induced epitope retrieval, ABC immunohistochemistry, multiple indirect immunofluorescence, confocal microscopy and cell quantification. Furthermore we present&#160;a sequential multiple immunofluorescence protocol which circumvents problems usually arising from the need of using primary antibodies raised in the same host species. It allows an accurate identification of all hippocampal progenitor subtypes together with a proliferation marker within a single section. These techniques are a powerful tool to study the regulation of different progenitor subtypes in parallel, their involvement in brain pathologies and their role in specific brain functions.

We applied the methods described above to quantify and characterize newborn cells in the postnatal and adult hippocampus. Therefore, we used wildtype and neurogenesis-deficient cyclin D2 knock out (Ccnd2KO) mice housed under conditions known to affect the rate of neurogenesis (i.e., enriched environment, EE)13,14. Immunohistochemical DAB staining against either Ki67, BrdU, CldU or IdU consistently revealed differences in newborn cell numbers between wildtype and Ccnd2KO mice (<strong...

Watch this Scientific Journal Video about Immunohistochemistry and Multiple Labeling with Antibodies from the Same Host Species to Study Adult Hippocampal Neurogenesis at JoVE.com

Immunohistochemistry and Multiple Labeling with Antibodies from the Same Host Species to Study Adult Hippocampal Neurogenesis

This video article illustrates a comprehensive protocol to detect and quantify all stages of adult hippocampal neurogenesis within the same tissue section. We elaborated a method to overcome the limitations of indirect multiple immunofluorescence that arise when suitable antibodies from different host species are unavailable.

Adult neurogenesis is a highly regulated, multi-stage process in which new neurons are generated from an activated neural stem cell via increasingly ...

immunohistochemistry-multiple-labeling-with-antibodies-from-same-host

Research

JoVE Journal

Neuroscience

26.4K Views.  Jena University Hospital. This video article illustrates a comprehensive protocol to detect and quantify all stages of adult hippocampal neurogenesis within the same tissue section. We elaborated a method to overcome the limitations of indirect multiple immunofluorescence that arise when suitable antibodies from different host species are unavailable.

Video: Immunohistochemistry and Multiple Labeling with Antibodies from the Same Host Species to Study Adult Hippocampal Neurogenesis

Dissection and Immunohistochemistry of Larval, Pupal and Adult Drosophila Retinas

The compound eye of Drosophila melanogaster consists of about 750 ommatidia (unit eyes). Each ommatidium is composed of about 20 cells, including lens-secreting cone cells, pigment cells, a bristle cell and eight photoreceptors (PRs) R1-R8 2. The PRs have specialized microvillar structures, the rhabdomeres, which contain light-sensitive pigments, the Rhodopsins (Rhs). The rhabdomeres of six PRs (R1-R6) form a trapezoid and contain Rh1 3 4. The rhabdomeres of R7 and R8 are positioned in tandem in the center of the trapezoid and share the same path of light. R7 and R8 PRs stochastically express different combinations of Rhs in two main subtypes5: In the 'p' subtype, Rh3 in pR7s is coupled with Rh5 in pR8s, whereas in the 'y' subtype, Rh4 in yR7s is associated with Rh6 in yR8s 6 7 8.
Early specification of PRs and development of ommatidia begins in the larval eye-antennal imaginal disc, a monolayer of epithelial cells. A wave of differentiation sweeps across the disc9 and initiates the assembly of undifferentiated cells into ommatidia10-11. The 'founder cell' R8 is specified first and recruits R1-6 and then R7 12-14. Subsequently, during pupal development, PR differentiation leads to extensive morphological changes 15, including rhabdomere formation, synaptogenesis and eventually rh expression.
In this protocol, we describe methods for retinal dissections and immunohistochemistry at three defined periods of retina development, which can be applied to address a variety of questions concerning retinal formation and developmental pathways. Here, we use these methods to visualize the stepwise PR differentiation at the single-cell level in whole mount larval, midpupal and adult retinas (Figure 1).

Dissection and Immunohistochemistry of Larval, Pupal and Adult Drosophila Retinas

The Drosophila retina is a crystal-like lattice composed of a small number of cell types that are generated in a stereotyped manner 1. Its amenability to sophisticated genetic analysis allows the study of complex developmental programs. This protocol describes dissections and immunohistochemistry of retinas at three discrete developmental stages, with a focus on photoreceptor differentiation.

The compound eye of Drosophila melanogaster consists of about 750 ommatidia (unit eyes). Each ommatidium is composed of about 20 cells, including ...

Functional Interrogation of Adult Hypothalamic Neurogenesis with Focal Radiological Inhibition

The functional characterization of adult-born neurons remains a significant challenge. Approaches to inhibit adult neurogenesis via invasive viral delivery or transgenic animals have potential confounds that make interpretation of results from these studies difficult. New radiological tools are emerging, however, that allow one to noninvasively investigate the function of select groups of adult-born neurons through accurate and precise anatomical targeting in small animals. Focal ionizing radiation inhibits the birth and differentiation of new neurons, and allows targeting of specific neural progenitor regions. In order to illuminate the potential functional role that adult hypothalamic neurogenesis plays in the regulation of physiological processes, we developed a noninvasive focal irradiation technique to selectively inhibit the birth of adult-born neurons in the hypothalamic median eminence. We describe a method for Computer tomography-guided focal irradiation (CFIR) delivery to enable precise and accurate anatomical targeting in small animals. CFIR uses three-dimensional volumetric image guidance for localization and targeting of the radiation dose, minimizes radiation exposure to nontargeted brain regions, and allows for conformal dose distribution with sharp beam boundaries. This protocol allows one to ask questions regarding the function of adult-born neurons, but also opens areas to questions in areas of radiobiology, tumor biology, and immunology. These radiological tools will facilitate the translation of discoveries at the bench to the bedside.

The function of adult-born mammalian neurons remains an active area of investigation. Ionizing radiation inhibits the birth of new neurons. Using computer tomography-guided focal irradiation (CFIR), three-dimensional anatomical targeting of specific neural progenitor populations can now be used to assess the functional role of adult neurogenesis.

The functional characterization of adult-born neurons remains a significant challenge. Approaches to inhibit adult neurogenesis via invasive viral ...

Heat-Induced Antigen Retrieval: An Effective Method to Detect and Identify Progenitor Cell Types during Adult Hippocampal Neurogenesis

Traditional methods of immunohistochemistry (IHC) following tissue fixation allow visualization of various cell types. These typically proceed with the application of antibodies to bind antigens and identify cells with characteristics that are a function of the inherent biology and development. Adult hippocampal neurogenesis is a sequential process wherein a quiescent neural stem cell can become activated and proceed through stages of proliferation, differentiation, maturation and functional integration. Each phase is distinct with a characteristic morphology and upregulation of genes. Identification of these phases is important to understand the regulatory mechanisms at play and any alterations in this process that underlie the pathophysiology of debilitating disorders. Our heat-induced antigen retrieval approach improves the intensity of the signal that is detected and allows correct identification of the progenitor cell type. As discussed in this paper, it especially allows us to circumvent current problems in detection of certain progenitor cell types.

During adult hippocampal neurogenesis, a distinct set of genetic markers are expressed when a quiescent neural stem cell sequentially progresses and develops into a functionally integrated neuron in the circuit. Using heat-induced antigen retrieval, progenitor cell types that are otherwise difficult to detect are identified with improved effectiveness.

Traditional  methods of immunohistochemistry (IHC) following tissue fixation allow visualization  of various cell types. These typically proceed with the ...

Membrane Potential Dye Imaging of Ventromedial Hypothalamus Neurons From Adult Mice to Study Glucose Sensing

Studies of neuronal activity are often performed using neurons from rodents less than 2 months of age due to the technical difficulties associated with increasing connective tissue and decreased neuronal viability that occur with age. Here, we describe a methodology for the dissociation of healthy hypothalamic neurons from adult-aged mice. The ability to study neurons from adult-aged mice allows the use of disease models that manifest at a later age and might be more developmentally accurate for certain studies. Fluorescence imaging of dissociated neurons can be used to study the activity of a population of neurons, as opposed to using electrophysiology to study a single neuron. This is particularly useful when studying a heterogeneous neuronal population in which the desired neuronal type is rare such as for hypothalamic glucose sensing neurons. We utilized membrane potential dye imaging of adult ventromedial hypothalamic neurons to study their responses to changes in extracellular glucose. Glucose sensing neurons are believed to play a role in central regulation of energy balance. The ability to study glucose sensing in adult rodents is particularly useful since the predominance of diseases related to dysfunctional energy balance (e.g.&#160;obesity) increase with age.

The activity of single neurons from adult-aged mice can be studied by dissociating neurons from specific brain regions and using fluorescent membrane potential dye imaging. By testing responses to changes in glucose, this technique can be used to study the glucose sensitivity of adult ventromedial hypothalamic neurons.

Studies of neuronal activity are often performed using neurons from rodents less than 2 months of age due to the technical difficulties associated with ...

Methods for the Modulation and Analysis of NF-&#954;B-dependent Adult Neurogenesis

The hippocampus plays a pivotal role in the formation and consolidation of episodic memories, and in spatial orientation. Historically, the adult hippocampus has been viewed as a very static anatomical region of the mammalian brain. However, recent findings have demonstrated that the dentate gyrus of the hippocampus is an area of tremendous plasticity in adults, involving not only modifications of existing neuronal circuits, but also adult neurogenesis. This plasticity is regulated by complex transcriptional networks, in which the transcription factor NF-&#954;B plays a prominent role. To study and manipulate adult neurogenesis, a transgenic mouse model for forebrain-specific neuronal inhibition of NF-&#954;B activity can be used.
In this study, methods are described for the analysis of NF-&#954;B-dependent neurogenesis, including its structural aspects, neuronal apoptosis and progenitor proliferation, and cognitive significance, which was specifically assessed via a dentate gyrus (DG)-dependent behavioral test, the spatial pattern separation-Barnes maze (SPS-BM). The SPS-BM protocol could be simply adapted for use with other transgenic animal models designed to assess the influence of particular genes on adult hippocampal neurogenesis. Furthermore, SPS-BM could be used in other experimental settings aimed at investigating and manipulating DG-dependent learning, for example, using pharmacological agents.

Methods for the Modulation and Analysis of NF-&amp;#954;B-dependent Adult Neurogenesis

Methods for the manipulation and analysis of NF-&#954;B-dependent adult hippocampal neurogenesis are described. A detailed protocol is presented for a dentate gyrus-dependent behavioral test (termed the spatial pattern separation-Barnes maze) for the investigation of cognitive outcome in mice. This technique should also help enable investigations in other experimental settings.

The hippocampus plays a pivotal role in the formation and consolidation of episodic memories, and in spatial orientation. Historically, the adult ...

Retrograde Labeling of Retinal Ganglion Cells in Adult Zebrafish with Fluorescent Dyes

As retrograde labeling retinal ganglion cells (RGCs) can isolate RGCs somata from dying sites, it has become the gold standard for counting RGCs in RGCs survival and regeneration experiments. Many studies have been performed in mammalian animals to research RGCs survival after optic nerve injury. However, retrograde labeling of RGCs in adult zebrafish has not yet been reported, though some alternative methods can count cell numbers in retinal ganglion cell layers (RGCL). Considering the small size of the adult zebrafish skull and the high risk of death after drilling on the skull, we open the skull with the help of acid-etching and seal the hole with a light curing bond, which could significantly improve the survival rate. After absorbing the dyes for 5 days, almost all the RGCs are labeled. As this method does not need to transect the optic nerve, it is irreplaceable in the research of RGCs survival after optic nerve crush in adult zebrafish. Here, we introduce this method step by step and provide representative results.

We introduce an efficient method to retrograde label retinal ganglion cells (RGCs) in adult zebrafish.

As retrograde labeling retinal ganglion cells (RGCs) can isolate RGCs somata from dying sites, it has become the gold standard for counting RGCs in RGCs ...

Juxtasomal Biocytin Labeling to Study the Structure-function Relationship of Individual Cortical Neurons

The cerebral cortex is characterized by multiple layers and many distinct cell-types that together as a network are responsible for many higher cognitive functions including decision making, sensory-guided behavior or memory. To understand how such intricate neuronal networks perform such tasks, a crucial step is to determine the function (or electrical activity) of individual cell types within the network, preferentially when the animal is performing a relevant cognitive task. Additionally, it is equally important to determine the anatomical structure of the network and the morphological architecture of the individual neurons to allow reverse engineering the cortical network. Technical breakthroughs available today allow recording cellular activity in awake, behaving animals with the valuable option of post&#160;hoc identifying the recorded neurons. Here, we demonstrate the juxtasomal biocytin labeling technique, which involves recording action potential spiking in the extracellular (or loose-patch) configuration using conventional patch pipettes. The juxtasomal recording configuration is relatively stable and applicable across behavioral conditions, including anesthetized, sedated, awake head-fixed, and even in the freely moving animal. Thus, this method allows linking cell-type specific action potential spiking during animal behavior to reconstruction of the individual neurons and ultimately, the entire cortical microcircuit. In this video manuscript, we show how individual neurons in the juxtasomal configuration can be labeled with biocytin in the urethane-anaesthetized rat for post&#160;hoc identification and morphological reconstruction.

To understand the structure of neuronal networks, functional and morphological characterization of individual neurons is a necessity. Here, we demonstrate juxtasomal biocytin labeling, which allows electrophysiological recordings in the extracellular configuration, yet maintaining the ability to intracellularly label the neuron for post&#160;hoc reconstruction of dendritic and axonal architecture.

The cerebral cortex is characterized by multiple layers and many distinct cell-types that together as a network are responsible for many higher cognitive ...

Stab Wound Injury of the Zebrafish Adult Telencephalon: A Method to Investigate Vertebrate Brain Neurogenesis and Regeneration

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular mechanisms involved in zebrafish adult central nervous system (CNS) regeneration and repair, we developed a zebrafish model of adult telencephalic injury.
In this approach, we manually generate an injury by pushing an insulin syringe needle into the zebrafish adult telencephalon. At different post injury days, fish are sacrificed, their brains are dissected out and stained by immunohistochemistry and/or in situ hybridization (ISH) with appropriate markers to observe cell proliferation, gliogenesis, and neurogenesis. The contralateral unlesioned hemisphere serves as an internal control. This method combined for example with RNA deep sequencing can help to screen for new genes with a role in zebrafish adult telencephalon neurogenesis, regeneration, and repair.

To shed light on the cellular and molecular mechanisms of zebrafish adult neurogenesis and regeneration, we developed a protocol for invasive surgery causing mechanical injuries in the zebrafish adult telencephalon and subsequent monitoring of changes in the stabbed hemisphere by immunohistochemistry or in situ hybridization.

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular ...

Assessing Primary Neurogenesis in Xenopus Embryos Using Immunostaining

Primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. During this process, a portion of neural stem cells undergo differentiation and give rise to the first populations of differentiated primary neurons within the nascent central nervous system. Several vertebrate model organisms have been used to explore the mechanisms of neural cell fate specification, patterning, and differentiation. Among these is the African clawed frog, Xenopus, which provides a powerful system for investigating the molecular and cellular mechanisms responsible for primary neurogenesis due to its rapid and accessible development and ease of embryological and molecular manipulations. Here, we present a convenient and rapid method to observe the different populations of neuronal cells within Xenopus central nervous system. Using antibody staining and immunofluorescence on sections of Xenopus embryos, we are able to observe the locations of neural stem cells and differentiated primary neurons during primary neurogenesis.

Assessing Primary Neurogenesis in Xenopus Embryos Using Immunostaining

This article presents a convenient and rapid method for visualizing different neuronal cell populations in the central nervous system of Xenopus embryos using immunofluorescent staining on sections.

Primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. During ...

Minimizing Hypoxia in Hippocampal Slices from Adult and Aging Mice

Acute hippocampal slices have enabled generations of neuroscientists to explore synaptic, neuronal, and circuit properties in detail and with high fidelity. Exploration of LTP and LTD mechanisms, single neuron dendritic computation, and experience-dependent changes in circuitry, would not have been possible without this classical preparation. However, with a few exceptions, most basic research using acute hippocampal slices has been performed using slices from rodents of relatively young ages, ~P20-P40, even though synaptic and intrinsic excitability mechanisms have a long developmental tail that reaches past P60. The main appeal of using young hippocampal slices is preservation of neuronal health aided by higher tolerance to hypoxic damage. However, there is a need to understand neuronal function at more mature stages of development, further accentuated by the development of various animal models of neurodegenerative diseases that require an aging brain preparation. Here we describe a modification to an acute hippocampal slice preparation that reliably delivers healthy slices from adult and aging mouse hippocampi. The protocol&#8217;s critical steps are transcardial perfusion and cutting with ice-cold sodium-free NMDG-aSCF. Together, these steps attenuate the hypoxia-induced drop in ATP upon decapitation, as well as cytotoxic edema caused by passive sodium fluxes. We demonstrate how to cut transversal slices of hippocampus plus cortex using a vibrating microtome. Acute hippocampal slices obtained in this way are reliably healthy over many hours of recording, and are appropriate for both field-recordings and targeted patch-clamp recordings, including targeting of fluorescently labeled neurons.

This is a protocol for acute slice preparation from adult and aging mouse hippocampi that takes advantage of transcardial perfusion and slice cutting with ice-cold NMDG-aCSF to reduce hypoxic damage to the tissue. The resulting slices stay healthy over many hours, and are suitable for long-term patch-clamp and field-recordings.