This work was supported by JSPS KAKENHI Grant Number 18K14824 and 21K15195 and an internal grant of AIST, Japan.

All experimental protocols were approved by the Institutional Animal Care and Use Committee at the National Institute of Advanced Industrial Science and Technology. Zebrafish and medaka were maintained according to standard procedures28.
1. Stab wound injury in the adult optic tectum
<ol>
	<li>Prepare a 0.4% (w/v) tricaine stock solution for anesthesia. For a 100 mL stock solution, dissolve 400 mg tricaine methanesulfonate (see Table of Materi...

<ol>
	<li>Becker, T., Wullimann, M. F., Becker, C. G., Bernhardt, R. R., Schachner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axonal+regrowth+after+spinal+cord+transection+in+adult+zebrafish.">Axonal regrowth after spinal cord transection in adult zebrafish.</a> Journal of Comparative Neurology. 377 (4), 577-595 (1997).</li><li>Raymond, P. A., Barthel, L. K., Bernardos, R. L., Perkowski, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+characterization+of+retinal+stem+cells+and+their+niches+in+adult+zebrafish.">Molecular characterization of retinal stem cells and their niches in adult zebrafish.</a> BMC Developmental Biology. 6, 36 (2006).</li><li>M&#228;rz, M., Schmidt, R., Rastegar, S., Str&#228;hle, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regenerative+response+following+stab+injury+in+the+adult+zebrafish+telencephalon.">Regenerative response following stab injury in the adult zebrafish telencephalon.</a> Developmental Dynamics. 240 (9), 2221-2231 (2011).</li><li>Kang, J., 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=Modulation+of+tissue+repair+by+regeneration+enhancer+elements.">Modulation of tissue repair by regeneration enhancer elements.</a> Nature. 532 (7598), 201-206 (2016).</li><li>Sim&#245;es, F. C., 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=Macrophages+directly+contribute+collagen+to+scar+formation+during+zebrafish+heart+regeneration+and+mouse+heart+repair.">Macrophages directly contribute collagen to scar formation during zebrafish heart regeneration and mouse heart repair.</a> Nature Communications. 11 (1), 600 (2020).</li><li>Hoang, 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=Gene+regulatory+networks+controlling+vertebrate+retinal+regeneration.">Gene regulatory networks controlling vertebrate retinal regeneration.</a> Science. 370 (6519), (2020).</li><li>Alunni, A., Bally-Cuif, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+view+of+regenerative+neurogenesis+in+vertebrates.">A comparative view of regenerative neurogenesis in vertebrates.</a> Development. 143 (5), 741-753 (2016).</li><li>Diotel, N., L&#252;bke, L., Str&#228;hle, U., Rastegar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Common+and+distinct+features+of+adult+neurogenesis+and+regeneration+in+the+telencephalon+of+zebrafish+and+mammals.">Common and distinct features of adult neurogenesis and regeneration in the telencephalon of zebrafish and mammals.</a> Frontiers in Neuroscience. 14, 568930 (2020).</li><li>Labusch, M., Mancini, L., Morizet, D., Bally-Cuif, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conserved+and+divergent+features+of+adult+neurogenesis+in+zebrafish.">Conserved and divergent features of adult neurogenesis in zebrafish.</a> Frontiers in Cell and Developmental Biology. 8, 525 (2020).</li><li>Ito, K., 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=Differential+reparative+phenotypes+between+zebrafish+and+medaka+after+cardiac+injury.">Differential reparative phenotypes between zebrafish and medaka after cardiac injury.</a> Developmental Dynamics. 243 (9), 1106-1115 (2014).</li><li>Lai, S. L., 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=Reciprocal+analyses+in+zebrafish+and+medaka+reveal+that+harnessing+the+immune+response+promotes+cardiac+regeneration.">Reciprocal analyses in zebrafish and medaka reveal that harnessing the immune response promotes cardiac regeneration.</a> eLife. 6, 25605 (2017).</li><li>Lust, K., Wittbrodt, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activating+the+regenerative+potential+of+M&#252;ller+glia+cells+in+a+regeneration-deficient+retina.">Activating the regenerative potential of M&#252;ller glia cells in a regeneration-deficient retina.</a> eLife. 7, 32319 (2018).</li><li>Shimizu, Y., Kawasaki, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+regenerative+capacity+of+the+optic+tectum+of+adult+medaka+and+zebrafish.">Differential regenerative capacity of the optic tectum of adult medaka and zebrafish.</a> Frontiers in Cell and Developmental Biology. 9, 686755 (2021).</li><li>Adolf, B., 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=Conserved+and+acquired+features+of+adult+neurogenesis+in+the+zebrafish+telencephalon.">Conserved and acquired features of adult neurogenesis in the zebrafish telencephalon.</a> Developmental Biology. 295 (1), 278-293 (2006).</li><li>Grandel, H., Kaslin, J., Ganz, J., Wenzel, I., Brand, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+stem+cells+and+neurogenesis+in+the+adult+zebrafish+brain:+origin,+proliferation+dynamics,+migration+and+cell+fate.">Neural stem cells and neurogenesis in the adult zebrafish brain: origin, proliferation dynamics, migration and cell fate.</a> Developmental Biology. 295 (1), 263-277 (2006).</li><li>Alunni, A., 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=Evidence+for+neural+stem+cells+in+the+medaka+optic+tectum+proliferation+zones.">Evidence for neural stem cells in the medaka optic tectum proliferation zones.</a> Developmental Neurobiology. 70 (10), 693-713 (2010).</li><li>Kuroyanagi, Y., 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=Proliferation+zones+in+adult+medaka+(Oryzias+latipes)+brain.">Proliferation zones in adult medaka (Oryzias latipes) brain.</a> Brain Research. 1323, 33-40 (2010).</li><li>Ito, Y., Tanaka, H., Okamoto, H., Ohshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+neural+stem+cells+and+their+progeny+in+the+adult+zebrafish+optic+tectum.">Characterization of neural stem cells and their progeny in the adult zebrafish optic tectum.</a> Developmental Biology. 342 (1), 26-38 (2010).</li><li>Shimizu, Y., Ueda, Y., Ohshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt+signaling+regulates+proliferation+and+differentiation+of+radial+glia+in+regenerative+processes+after+stab+injury+in+the+optic+tectum+of+adult+zebrafish.">Wnt signaling regulates proliferation and differentiation of radial glia in regenerative processes after stab injury in the optic tectum of adult zebrafish.</a> Glia. 66 (7), 1382-1394 (2018).</li><li>Ueda, Y., Shimizu, Y., Shimizu, N., Ishitani, T., Ohshima, T. <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+sonic+hedgehog+and+notch+signaling+in+regenerative+neurogenesis+in+adult+zebrafish+optic+tectum+after+stab+injury.">Involvement of sonic hedgehog and notch signaling in regenerative neurogenesis in adult zebrafish optic tectum after stab injury.</a> Journal of Comparative Neurology. 526 (15), 2360-2372 (2018).</li><li>Kiyooka, M., Shimizu, Y., Ohshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histone+deacetylase+inhibition+promotes+regenerative+neurogenesis+after+stab+wound+injury+in+the+adult+zebrafish+optic+tectum.">Histone deacetylase inhibition promotes regenerative neurogenesis after stab wound injury in the adult zebrafish optic tectum.</a> Biochemical and Biophysical Research Communications. 529 (2), 366-371 (2020).</li><li>Shimizu, Y., Kawasaki, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histone+acetyltransferase+EP300+regulates+the+proliferation+and+differentiation+of+neural+stem+cells+during+adult+neurogenesis+and+regenerative+neurogenesis+in+the+zebrafish+optic+tectum.">Histone acetyltransferase EP300 regulates the proliferation and differentiation of neural stem cells during adult neurogenesis and regenerative neurogenesis in the zebrafish optic tectum.</a> Neuroscience Letters. 756, 135978 (2021).</li><li>Shimizu, Y., Kiyooka, M., Ohshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptome+analyses+reveal+IL6/Stat3+signaling+involvement+in+radial+glia+proliferation+after+stab+wound+injury+in+the+adult+zebrafish+optic+tectum.">Transcriptome analyses reveal IL6/Stat3 signaling involvement in radial glia proliferation after stab wound injury in the adult zebrafish optic tectum.</a> Frontiers in Cell and Developmental Biology. 9, 668408 (2021).</li><li>Lindsey, B. W., 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=Midbrain+tectal+stem+cells+display+diverse+regenerative+capacities+in+zebrafish.">Midbrain tectal stem cells display diverse regenerative capacities in zebrafish.</a> Scientific Reports. 9 (1), 4420 (2019).</li><li>Yu, S., He, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stochastic+cell-cycle+entry+and+cell-state-dependent+fate+outputs+of+injury-reactivated+tectal+radial+glia+in+zebrafish.">Stochastic cell-cycle entry and cell-state-dependent fate outputs of injury-reactivated tectal radial glia in zebrafish.</a> eLife. 8, 48660 (2019).</li><li>Bisese, E. C., 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=The+acute+transcriptome+response+of+the+midbrain/diencephalon+to+injury+in+the+adult+mummichog+(Fundulus+heteroclitus).">The acute transcriptome response of the midbrain/diencephalon to injury in the adult mummichog (Fundulus heteroclitus).</a> Molecular Brain. 12 (1), 119 (2019).</li><li>Schmidt, R., Beil, T., Str&#228;hle, U., Rastegar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stab+wound+injury+of+the+zebrafish+adult+telencephalon:+a+method+to+investigate+vertebrate+brain+neurogenesis+and+regeneration.">Stab wound injury of the zebrafish adult telencephalon: a method to investigate vertebrate brain neurogenesis and regeneration.</a> Journal of Visualized Experiments. (4), e51753 (2014).</li><li>Westerfield, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The zebrafish book. A guide for the laboratory use of zebrafish (Danio rerio) 5th ed. , (2007).</li><li>Kaslin, J., Kroehne, V., Ganz, J., Hans, S., Brand, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+roles+of+neuroepithelial-like+and+radial+glia-like+progenitor+cells+in+cerebellar+regeneration.">Distinct roles of neuroepithelial-like and radial glia-like progenitor cells in cerebellar regeneration.</a> Development. 144 (8), 1462-1471 (2017).</li><li>Curado, S., 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=Conditional+targeted+cell+ablation+in+zebrafish:+a+new+tool+for+regeneration+studies.">Conditional targeted cell ablation in zebrafish: a new tool for regeneration studies.</a> Developmental Dynamics. 236 (4), 1025-1035 (2007).</li><li>Shimizu, Y., Ito, Y., Tanaka, H., Ohshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radial+glial+cell-specific+ablation+in+the+adult+zebrafish+brain.">Radial glial cell-specific ablation in the adult zebrafish brain.</a> Genesis. 53 (7), 431-439 (2015).</li><li>Godoy, R., 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=Dopaminergic+neurons+regenerate+following+chemogenetic+ablation+in+the+olfactory+bulb+of+adult+zebrafish+(Danio+rerio).">Dopaminergic neurons regenerate following chemogenetic ablation in the olfactory bulb of adult zebrafish (Danio rerio).</a> Scientific Reports. 10 (1), 12825 (2020).</li><li>Sawahata, M., Izumi, Y., Akaike, A., Kume, T. <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+brain+ischemia-reperfusion+model+induced+by+hypoxia-reoxygenation+using+zebrafish+larvae.">In vivo brain ischemia-reperfusion model induced by hypoxia-reoxygenation using zebrafish larvae.</a> Brain Research Bulletin. 173, 45-52 (2021).</li></ol>

Here a set of methods is described which can be used to induce stab wound injuries in the optic tectum utilizing a needle to facilitate the evaluation of RGC proliferation and differentiation after brain injury. Needle-mediated stab wounds are a simple, efficiently implemented method that can be applied to many experimental samples using a standard set of tools. Stab wound injury models for several regions of the zebrafish brain have been developed3,19,</sup...

Zebrafish (Danio rerio) have an increased ability to regenerate their central nervous system (CNS) compared to other mammals1,2,3. Recently, to better understand the molecular mechanisms underlying this increased regenerative capacity, comparative analyses of tissue regeneration using next-generation sequencing technology have been performed4,5,6. The brain structures in zebrafish and tetrapods are quite different7,8,9. This means that several brain injury models using small fish with similar brain structures and biological features have been developed to facilitate the investigation of the underlying molecular mechanisms contributing to this increased regenerative capacity.
In addition, medaka (Oryzias latipes) is a popular laboratory animal with a low capacity for heart and neuronal regeneration10,11,12,13 compared with zebrafish. Zebrafish and medaka have similar brain structures and niches for adult neural stem cells (NSCs)14,15,16,17. In zebrafish and medaka, the optic tectum includes two types of NSCs, neuroepithelial-like stem cells and radial glial cells (RGCs)15,18. A stab wound injury for the optic tectum of adult zebrafish was previously developed, and this model was used to investigate the molecular mechanisms regulating brain regeneration in these animals19,20,21,22,23. This young adult zebrafish stab wound injury model induced regenerative neurogenesis from RGCs19,24,25. This stab wound injury in the optic tectum is a robust and reproducible method13,19,20,21,22,23,24,25. When the same injury model was applied to adult medaka, the low neurogenic capacity of RGCs in medaka optic tectum was revealed via the comparative analysis of RGC proliferation and differentiation following injury13.
Stab wound injury models in the optic tectum have also been developed in mummichog models26, but details of the tectum injury have been not well documented when compared with telencephalic injury27. The stab wound injury in the optic tectum using zebrafish and medaka allows the investigation of the differential cellular responses and gene expression between species with differential regenerative capacity. This protocol describes how to perform a stab wound injury in the optic tectum using an injection needle. This method can be applied to small fish like zebrafish and medaka. The processes for sample preparation for histological analysis and cellular proliferation and differentiation analysis using fluorescent immunohistochemistry and cryosections are explained here.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>10 mL syringe</td>
			<td>TERUMO</td>
			<td>SS-10ESZ</td>
			<td></td>
		</tr>
		<tr>
			<td>1M Tris-HCl (pH 9.0)</td>
			<td>NIPPON GENE</td>
			<td>314-90381</td>
			<td></td>
		</tr>
		<tr>
			<td>30 G needle</td>
			<td>Dentronics</td>
			<td>HS-2739A</td>
			<td></td>
		</tr>
		<tr>
			<td>4% Paraformaldehyde Phosphate Buffer Solution</td>
			<td>Wako</td>
			<td>163-20145</td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum block</td>
			<td></td>
			<td></td>
			<td>115 x 80 x 37 mm (W x D x H) is enough size to freeze 6 cryomolds</td>
		</tr>
		<tr>
			<td>Anti-BLBP</td>
			<td>Millipore</td>
			<td>ABN14</td>
			<td>1:500</td>
		</tr>
		<tr>
			<td>Anti-BrdU</td>
			<td>Abcam</td>
			<td>ab1893</td>
			<td>1:500</td>
		</tr>
		<tr>
			<td>Anti-HuC</td>
			<td>Invitrogen</td>
			<td>A21271</td>
			<td>1:100</td>
		</tr>
		<tr>
			<td>Anti-PCNA</td>
			<td>Santa Cruz Biotechnology</td>
			<td>sc-56</td>
			<td>1:200</td>
		</tr>
		<tr>
			<td>Brmodeoxyuridine</td>
			<td>Wako</td>
			<td>023-15563</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microscope C1 plus</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cryomold</td>
			<td>Sakura Finetek Japan</td>
			<td>4565</td>
			<td>10 x 10 x 5 mm (W x D x H)</td>
		</tr>
		<tr>
			<td>Cryostat</td>
			<td>Leica</td>
			<td>CM1960</td>
			<td></td>
		</tr>
		<tr>
			<td>Danio rerio WT strains RW</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Extension tube</td>
			<td>TERUMO</td>
			<td>SF-ET3520</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluoromount (TM) Aqueous Mounting Medium, for use with fluorescent dye-stained tissues</td>
			<td>SIGMA-ALDRICH</td>
			<td>F4680-25ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>DUMONT</td>
			<td>11252-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Mouse IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor Plus 488</td>
			<td>Invitrogen</td>
			<td>A32723</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Rabbit IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 546</td>
			<td>Invitrogen</td>
			<td>A11035</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst 33342 solution</td>
			<td>Dojindo</td>
			<td>23491-52-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric Acid</td>
			<td>Wako</td>
			<td>080-01066</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubation Chamber for 10 slides Dark Orange</td>
			<td>COSMO BIO CO., LTD.</td>
			<td>10DO</td>
			<td></td>
		</tr>
		<tr>
			<td>MAS coat sliding glass</td>
			<td>Matsunami glass</td>
			<td>MAS-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro cover glass</td>
			<td>Matsunami glass</td>
			<td>C024451</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscopy</td>
			<td>Nikon</td>
			<td>SMZ745T</td>
			<td></td>
		</tr>
		<tr>
			<td>Normal horse serum blocking solution</td>
			<td>VECTOR LABRATORIES</td>
			<td>S-2000-20</td>
			<td></td>
		</tr>
		<tr>
			<td>O.C.T Compound</td>
			<td>Sakura Finetek Japan</td>
			<td>83-1824</td>
			<td></td>
		</tr>
		<tr>
			<td>Oryzias latipes WT strains Cab</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PAP Pen Super-Liquid Blocker</td>
			<td>DAIDO SANGYO</td>
			<td>PAP-S</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (PBS) Tablets, pH 7.4</td>
			<td>TaKaRa</td>
			<td>T9181</td>
			<td></td>
		</tr>
		<tr>
			<td>Styrofoam tray</td>
			<td></td>
			<td></td>
			<td>100 x 100 x 10 mm (W x D x H) styrofoam sheet is available as tray</td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Wako</td>
			<td>196-00015</td>
			<td>30 % (w/v) Sucrose in PBS</td>
		</tr>
		<tr>
			<td>Tricaine (MS-222)</td>
			<td>nacarai tesque</td>
			<td>14805-24</td>
			<td></td>
		</tr>
		<tr>
			<td>Trisodium Citrate Dihydrate</td>
			<td>Wako</td>
			<td>191-01785</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Wako</td>
			<td>04605-250</td>
			<td></td>
		</tr>
	</tbody>
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stab wound injury model of the adult optic tectum using zebrafish and medaka for the comparative analysis of regenerative capacity

While zebrafish have a superior capacity to regenerate their central nervous system (CNS), medaka has a lower CNS regenerative capacity. A brain injury model was developed in the adult optic tectum of zebrafish and medaka and comparative histological and molecular analyses were performed to elucidate the molecular mechanisms regulating the high regenerative capacity of this tissue across these fish species. Here a stab wound injury model is presented for the adult optic tectum using a needle and histological analyses for proliferation and differentiation of the neural stem cells (NSCs). A needle was manually inserted into the central region of the optic tectum, and then the fish were intracardially perfused, and their brains were dissected. These tissues were then cryosectioned and evaluated using immunostaining against the appropriate NSC proliferation and differentiation markers. This tectum injury model provides robust and reproducible results in both zebrafish and medaka, allowing for comparing NSC responses after injury. This method is available for small teleosts, including zebrafish, medaka, and African killifish, and enables us to compare their regenerative capacity and investigate unique molecular mechanisms.

Stab wound injury in the optic tectum using needle insertion into the right hemisphere (Figure 1, Figure 4A, and Figure 5A) induces various cellular responses, including radial glial cell (RGC) proliferation and the generation of newborn neurons. Similarly, aged populations of zebrafish and medaka were used to counteract any aging effects in the regenerative response. Then fluorescent immunostaining was performed on the frozen secti...

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Stab Wound Injury Model of the Adult Optic Tectum Using Zebrafish and Medaka for the Comparative Analysis of Regenerative Capacity

A mechanical brain injury model in the adult zebrafish is described to investigate the molecular mechanisms regulating their high regenerative capacity. The method explains to create a stab wound injury in the optic tectum of multiple species of small fish to evaluate the regenerative responses using fluorescent immunostaining.

While zebrafish have a superior capacity to regenerate their central nervous system (CNS), medaka has a lower CNS regenerative capacity. A brain injury ...

Stab wound injury is a mechanical injury method that induces nonspecific cell ablation. This method facilitates the evaluation of RGC proliferation and differentiation after brain injury. Needle-mediated stab wound injury is a simple, efficiently-implemented method to induce brain injury.This method can be applied to many experimental samples using a standard set of tools. The regenerative capacity of zebrafish was illustrated using the stab wound injury model. New insights into molecular mechanism regulating neuronal regeneration contribute to regenerative therapy in the central nervous system.Begin by placing an anesthetized adult zebrafish or medaka on a styrofoam tray. Fix the fish upright between two 30-gauge needles inserted vertically into the styrofoam. Hold the fish body to prevent the fish head from moving, and then vertically insert a 30-gauge needle through the skull into the medial region of one of the optic tectum spheres.Next, transfer the injured fish into a fish tank with fresh fish facility water. Once the fish have fully recovered from the anesthesia, move the tank to the breeding system. Put paper towels on the styrofoam tray to place the anesthetized fish.Then hold the fish body in place by vertically inserting two 30-gauge needles on either side of the anal fin. Once the fish is placed, make a ventral incision from the anus to the heart. Keep the heart visible by inserting two 30-gauge needles on each side.Then use the tip of the forceps to remove the silver epithelial layer. Insert the 30-gauge needle into the ventricle, keeping the bevel up, and make an incision into the atrium using the forceps. Next, push PBS into the atrium by pressing down on the syringe to flush the blood from the atrium.When the blood is drained and the gills turn white, stop the PBS perfusion. Later, remove the needles fixing the fish body in place, and fix the fish ventral side down. After cutting the spinal cord and removing the skull from the optic tectum and telencephalon, cut the optic nerves and dissect the brain.Next, transfer the brains into 1.5-milliliter tubes with one milliliter of 4%paraformaldehyde in PBS, to fix overnight at four degrees Celsius. After washing the fixed brains three times in PBS for five minutes each, transfer the brains into 1.5-milliliter tubes with one milliliter of 30%weight by volume sucrose in PBS as a cryoprotectant, and incubate them overnight at four degrees Celsius. Prepare the embedding compound by combining 30%sucrose with 30 milliliters of optimal cutting temperature, or OCT, compound, and store the compound at four degrees Celsius.To cool the cryomold once, incubate an aluminum block overnight at minus 80 degrees Celsius, and put the pre-cooled block in a styrofoam box with a lid to prevent warming. For coronal sections, embed the dissected brain in a cryomold by adjusting the orientation using forceps under the microscope. Next, place the cryomold on the pre-cooled aluminum block in the styrofoam box, and allow the OCT compound to freeze and become white.As the compound freezes, apply a small circle of OCT compound on a specimen disc before mounting the cryoblock on the specimen disc. By placing the specimen disc in the cryostat, freeze the OCT compound. Then place the specimen disc on the specimen head in the cryostat.After setting the orientation of the cryoblock, trim the OCT to remove any extra regions. Cut 14-micrometer thick serial sections through the whole optic tectum using a cryostat, and store the slides at minus 25 degrees Celsius. The radial glial cell, or RGC, proliferation in the brain tissue of zebrafish was evaluated.Most RGCs were proliferating cell antigen negative in the contralateral uninjured hemisphere. At two days post-injury, RGC proliferation was induced on the injured side of the medaka tectum. After the brain injury, cell lineage and RGC differentiation were evaluated with bromodeoxyuridine, or BrdU, labeling.The representative analysis shows newborn neurons at seven days post-injury in the injured zebrafish and medaka. One of the critical steps in stab wound injuries is manual needle insertion. A consistent injury is necessary for creating reproducible results.Fluorescent dyes are effective as wound markers. The extent of fluorescent dye diffusion indicates the location and depth of the stab wound injury. This technique is potentially adapted to other small fish species, and adaptation to medaka allows for comparisons of regenerative capacity.

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Developmental Biology

1.6K Views.  National Institute of Advanced Industrial Science and Technology. La lesione da coltellata è un metodo di lesione meccanica che induce l'ablazione cellulare non specifica. Questo metodo facilita la valutazione della proliferazione e della differenziazione di RGC dopo lesione cerebrale. La lesione da coltellata mediata dall'ago è un metodo semplice ed efficiente per indurre lesioni cerebrali.Questo metodo può essere applicato a molti campioni sperimentali utilizzando un set standard di strumenti. La capacità rigenerativa del pesce zebra è stata i...