We greatly thank Direction des Usages du Num&#233;rique (DUN) from La R&#233;union University for editing the video (in particular, Jean-Fran&#231;ois F&#233;vrier, Eric Esnault, and Sylvain Ducasse), Lynda-Rose Mottagan for the voiceover, Mary Osborne-Pellegrin for proofreading the voice-over, and the CYROI platform. This work was supported by grants from La R&#233;union University (Bonus Qualit&#233; Recherche, Dispositifs incitatifs), Conseil R&#233;gional de La R&#233;union, European Union (CPER/FEDER), and Philancia association. ACD is a recipient of a fellowship grant from the Minist&#232;re de l&#39;Education Nationale, de l&#39;Enseignement Sup&#233;rieur et de la Recherche, La R&#233;union University (Contrat Doctoral).

Adult wildtype zebrafish (Danio rerio) were maintained under standard photoperiod (14/10 h light/dark) and temperature (28 &#176;C) conditions. All experiments were conducted in accordance with the French and European Community Guidelines for the Use of Animals in Research (86/609/EEC and 2010/63/EU) and were approved by the local Ethics Committee for animal experimentation.
1. Establishing a Model of Acute Hyperglycemia in Zebrafish
<ol>
	<li>Prepare a stock solution of tricaine (M...

<ol>
	<li>Ho, N., Sommers, M. S., Lucki, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+diabetes+on+hippocampal+neurogenesis:+links+to+cognition+and+depression.">Effects of diabetes on hippocampal neurogenesis: links to cognition and depression.</a> Neurosci Biobehav Rev. 37 (8), 1346-1362 (2013).</li><li>Cukierman, T., Gerstein, H. C., Williamson, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+decline+and+dementia+in+diabetes--systematic+overview+of+prospective+observational+studies.">Cognitive decline and dementia in diabetes--systematic overview of prospective observational studies.</a> Diabetologia. 48 (12), 2460-2469 (2005).</li><li>Gaudieri, P. A., Chen, R., Greer, T. F., Holmes, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+function+in+children+with+type+1+diabetes:+a+meta-analysis.">Cognitive function in children with type 1 diabetes: a meta-analysis.</a> Diabetes Care. 31 (9), 1892-1897 (2008).</li><li>Brismar, 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=Predictors+of+cognitive+impairment+in+type+1+diabetes.">Predictors of cognitive impairment in type 1 diabetes.</a> Psychoneuroendocrinology. 32 (8-10), 1041-1051 (2007).</li><li>Ojo, O., Brooke, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+the+Association+between+Diabetes,+Cognitive+Decline+and+Dementia.">Evaluating the Association between Diabetes, Cognitive Decline and Dementia.</a> Int J Environ Res Public Health. 12 (7), 8281-8294 (2015).</li><li>Capes, S. E., Hunt, D., Malmberg, K., Pathak, P., Gerstein, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+hyperglycemia+and+prognosis+of+stroke+in+nondiabetic+and+diabetic+patients:+a+systematic+overview.">Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview.</a> Stroke. 32 (10), 2426-2432 (2001).</li><li>Stead, L. G., 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=Hyperglycemia+as+an+independent+predictor+of+worse+outcome+in+non-diabetic+patients+presenting+with+acute+ischemic+stroke.">Hyperglycemia as an independent predictor of worse outcome in non-diabetic patients presenting with acute ischemic stroke.</a> Neurocrit Care. 10 (2), 181-186 (2009).</li><li>Kagansky, N., Levy, S., Knobler, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+hyperglycemia+in+acute+stroke.">The role of hyperglycemia in acute stroke.</a> Arch Neurol. 58 (8), 1209-1212 (2001).</li><li>Gilmore, R. M., Stead, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+hyperglycemia+in+acute+ischemic+stroke.">The role of hyperglycemia in acute ischemic stroke.</a> Neurocrit Care. 5 (2), 153-158 (2006).</li><li>Desilles, J. P., 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=Diabetes+mellitus,+admission+glucose,+and+outcomes+after+stroke+thrombolysis:+a+registry+and+systematic+review.">Diabetes mellitus, admission glucose, and outcomes after stroke thrombolysis: a registry and systematic review.</a> Stroke. 44 (7), 1915-1923 (2013).</li><li>Dorsemans, A. 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=Impaired+constitutive+and+regenerative+neurogenesis+in+adult+hyperglycemic+zebrafish.">Impaired constitutive and regenerative neurogenesis in adult hyperglycemic zebrafish.</a> J Comp Neurol. , (2016).</li><li>Schmidt, R., Str&#228;hle, U., Scholpp, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurogenesis+in+zebrafish+-+from+embryo+to+adult.">Neurogenesis in zebrafish - from embryo to adult.</a> Neural Dev. 8, 3 (2013).</li><li>Kizil, C., Kaslin, J., Kroehne, V., 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=Adult+neurogenesis+and+brain+regeneration+in+zebrafish.">Adult neurogenesis and brain regeneration in zebrafish.</a> Dev Neurobiol. 72 (3), 429-461 (2012).</li><li>Grandel, H., 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=Comparative+aspects+of+adult+neural+stem+cell+activity+in+vertebrates.">Comparative aspects of adult neural stem cell activity in vertebrates.</a> Dev Genes Evol. 223 (1-2), 131-147 (2013).</li><li>Lindsey, B. W., Tropepe, V. <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+framework+for+understanding+the+biological+principles+of+adult+neurogenesis.">A comparative framework for understanding the biological principles of adult neurogenesis.</a> Prog Neurobiol. 80 (6), 281-307 (2006).</li><li>M&#228;rz, M., 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=Heterogeneity+in+progenitor+cell+subtypes+in+the+ventricular+zone+of+the+zebrafish+adult+telencephalon.">Heterogeneity in progenitor cell subtypes in the ventricular zone of the zebrafish adult telencephalon.</a> Glia. 58 (7), 870-888 (2010).</li><li>Chapouton, P., Jagasia, R., 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=Adult+neurogenesis+in+non-mammalian+vertebrates.">Adult neurogenesis in non-mammalian vertebrates.</a> Bioessays. 29 (8), 745-757 (2007).</li><li>Lindsey, B. W., Darabie, A., Tropepe, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cellular+composition+of+neurogenic+periventricular+zones+in+the+adult+zebrafish+forebrain.">The cellular composition of neurogenic periventricular zones in the adult zebrafish forebrain.</a> J Comp Neurol. 520 (10), 2275-2316 (2012).</li><li>Sarras, M. P., Intine, R. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Zebrafish+as+a+Disease+Model+Provides+a+Unique+Window+For+Understanding+the+Molecular+Basis+of+Diabetic+Metabolic+Memory.">Use of Zebrafish as a Disease Model Provides a Unique Window For Understanding the Molecular Basis of Diabetic Metabolic Memory.</a> Zebrafish. , 2611-2619 (2012).</li><li>Oka, 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=Diet-induced+obesity+in+zebrafish+shares+common+pathophysiological+pathways+with+mammalian+obesity.">Diet-induced obesity in zebrafish shares common pathophysiological pathways with mammalian obesity.</a> BMC Physiol. 10, 21 (2010).</li><li>Capiotti, K. M., 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=Persistent+impaired+glucose+metabolism+in+a+zebrafish+hyperglycemia+model.">Persistent impaired glucose metabolism in a zebrafish hyperglycemia model.</a> Comp Biochem Physiol B Biochem Mol Biol. 171, 58-65 (2014).</li><li>Capiotti, K. M., 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=Hyperglycemia+induces+memory+impairment+linked+to+increased+acetylcholinesterase+activity+in+zebrafish+(Danio+rerio).">Hyperglycemia induces memory impairment linked to increased acetylcholinesterase activity in zebrafish (Danio rerio).</a> Behav Brain Res. 274, 319-325 (2014).</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> J Vis Exp. (90), e51753 (2014).</li><li>Diotel, N., 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=Effects+of+estradiol+in+adult+neurogenesis+and+brain+repair+in+zebrafish.">Effects of estradiol in adult neurogenesis and brain repair in zebrafish.</a> Horm Behav. 63 (2), 193-207 (2013).</li><li>Rodriguez Viales, 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=The+helix-loop-helix+protein+id1+controls+stem+cell+proliferation+during+regenerative+neurogenesis+in+the+adult+zebrafish+telencephalon.">The helix-loop-helix protein id1 controls stem cell proliferation during regenerative neurogenesis in the adult zebrafish telencephalon.</a> Stem Cells. 33 (3), 892-903 (2015).</li><li>Kaslin, J., Ganz, J., 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=Proliferation,+neurogenesis+and+regeneration+in+the+non-mammalian+vertebrate+brain.">Proliferation, neurogenesis and regeneration in the non-mammalian vertebrate brain.</a> Philos Trans R Soc Lond B Biol Sci. 363 (1489), 101-122 (2008).</li><li>Kroehne, V., Freudenreich, D., Hans, S., Kaslin, J., 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=Regeneration+of+the+adult+zebrafish+brain+from+neurogenic+radial+glia-type+progenitors.">Regeneration of the adult zebrafish brain from neurogenic radial glia-type progenitors.</a> Development. 138 (22), 4831-4841 (2011).</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>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> Dev Dyn. 240 (9), 2221-2231 (2011).</li><li>Wullimann, M., Rupp, B., Reichert, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Neuroanatomy of the zebrafish brain: A topological atlas. , 1-144 (1996).</li><li>Pellegrini, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+aromatase-positive+radial+glial+cells+as+progenitor+cells+in+the+ventricular+layer+of+the+forebrain+in+zebrafish.">Identification of aromatase-positive radial glial cells as progenitor cells in the ventricular layer of the forebrain in zebrafish.</a> J Comp Neurol. 501 (1), 150-167 (2007).</li><li>Zupanc, G. 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P., Baker, C., Fonde, L., Gerardi, E., Slack, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternate+Immersion+in+an+External+Glucose+Solution+Differentially+Affects+Blood+Sugar+Values+in+Older+Versus+Younger+Zebrafish+Adults.">Alternate Immersion in an External Glucose Solution Differentially Affects Blood Sugar Values in Older Versus Younger Zebrafish Adults.</a> Zebrafish. , (2016).</li><li>Prasad, S., Sajja, R. K., Naik, P., Cucullo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diabetes+Mellitus+and+Blood-Brain+Barrier+Dysfunction:+An+Overview.">Diabetes Mellitus and Blood-Brain Barrier Dysfunction: An Overview.</a> J Pharmacovigil. 2 (2), 125 (2014).</li></ol>

No potential conflicts of interest were disclosed.

This work describes various methods to establish acute and chronic models of hyperglycemia in zebrafish. The main advantages of these procedures are that: (1) they allow for a reduction in the number of mammals used for research, (2) they are simple to set up and quick to implement, and (3) they are economical. Therefore, such models allow for the investigation of the impact of hyperglycemia on a large number of animals to study its impact on different physiological processes, including atherothrombosis, cardiovascular d...

Hyperglycemia is defined as excessive blood glucose levels. Although it could reflect a situation of acute stress, hyperglycemia is also a condition that often leads to a diagnosis of diabetes, a chronic disorder of insulin secretion and/or resistance. In 2016, the number of adults living with diabetes has reached 422 million worldwide, and each year, 1.5 million people die from this disease, making it a major health problem1. Indeed, uncontrolled diabetes leads to several physiological disorders affecting the cardiovascular system, kidneys, and the peripheral and central nervous systems.
Interestingly, acute and chronic hyperglycemia may alter cognition and contribute to both dementia and depression2,3,4,5,6. In addition, the admission of patients with hyperglycemia has been associated with worse functional, neurological, and survival outcomes after ischemic stroke7,8,9,10,11. It was also shown that hyperglycemia/diabetes affect adult neurogenesis, a process leading to the generation of new neurons, by impacting neural stem cell activity and neuronal differentiation, migration, and survival2,12.
In contrast to mammals, teleost fish, like zebrafish, display intense neurogenic activity throughout the whole brain and exhibit an outstanding capacity for brain repair during adulthood13,14,15,16. Notably, such capacities are possible due to the persistence of neural stem/progenitor cells, including radial glia and neuroblasts17,18,19. In addition, the zebrafish has recently emerged as a model for studying metabolic disorders, including obesity and hyperglycemia/diabetes20,21,22.
Although the zebrafish is a well-recognized model of hyperglycemia and neurogenesis, few studies have investigated the impact of hyperglycemia on brain homeostasis and cognitive function12,23. To determine the impact of hyperglycemia on constitutive and injury-induced brain cell proliferation, a model of acute hyperglycemia was created through the intraperitoneal injection of D-glucose. In addition, a model of chronic hyperglycemia was reproduced through the immersion of fish in water supplemented with D-glucose12. Zebrafish exhibit many advantages in research. They are cheap, easy to raise, and transparent during the first stages of development, and their genome has been sequenced. In the context of this work, they also display several additional advantages: (1) they share similar physiological processes with humans, making them a critical tool for biomedical research; (2) they allow for the quick investigation of the impact of hyperglycemia on brain homeostasis and neurogenesis, given their widespread and strong neurogenic activity; and (3) they are an alternative model, allowing for the reduction of the number of mammals used in research. Finally, zebrafish can be used as a model for testing the biodistribution of radiolabeled molecules and potential therapeutic agents using PET/CT.
The overall goal of the following procedure is to visually document how to set up models of acute and chronic hyperglycemia in zebrafish, use zebrafish to assess brain remodeling in hyperglycemic conditions, and monitor radiolabeled molecules (here, [18F]-FDG) using PET/CT.

<table border="0" cellpadding="0" cellspacing="0" width="738">
	<tbody>
		<tr height="17">
			<td height="17" style="height:17px;width:328px;">1mL Luer-Lok Syringe</td>
			<td style="width:151px;">BD, USA</td>
			<td style="width:93px;">309628</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">4&#39;,6&#39;-diamidino-2-phenylindole (DAPI)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td style="width:93px;">D8417</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">7 mL bijou container plain lab</td>
			<td style="width:151px;">Dutscher, France</td>
			<td style="width:93px;">080171</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">D-glucose</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>67021</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Digital camera</td>
			<td>Life Sciences, Japan</td>
			<td>Hamamatsu ORCA-ER</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Disposable base molds&#160;</td>
			<td>Simport, Canada</td>
			<td>M475-2</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Donkey anti-rabbit Alexa fluor 488</td>
			<td>Life Technologies, USA</td>
			<td>A21206</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Embedding center</td>
			<td>Thermo Scientific, USA</td>
			<td>Shandon Histocentre 3</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Fluorescence microscope</td>
			<td>Nikon, Japan</td>
			<td>Eclipse 80i</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fluorodeoxyglucose (18F-FDG)</td>
			<td>Cyclotron, France</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Glucometer test strip</td>
			<td>LifeScan, France</td>
			<td>One-Touch 143 Ultra</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Goat anti-mouse Alexa fluor 594</td>
			<td>Life Technologies, USA</td>
			<td>A11005</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">In-Vivo Imaging System</td>
			<td>TriFoil Imaging, Canada</td>
			<td>Triumph Trimodality&#160;</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Microtome</td>
			<td>Thermo Scientific, USA</td>
			<td>Microm HM 355 S</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Monoclonal mouse anti-PCNA</td>
			<td>DAKO, USA</td>
			<td>clone PC10</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Paraformaldehyde (PFA)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>P6148-500G</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Polyclonal rabbit anti-GFAP</td>
			<td>DAKO, USA</td>
			<td>Z033429</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Slide drying bench</td>
			<td>Electrothermal, USA</td>
			<td>MH6616</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Sodium chloride</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>S9888</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Sodium citrate trisodium salt dehydrate&#160;</td>
			<td>Prolabo, France</td>
			<td>27833.294</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Sterile needle</td>
			<td>BD Microlance 3</td>
			<td>30 G 1/2 ; 0.3 mm x 13 mm</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Student Dumont #5 Forceps</td>
			<td>Fine Science Tools</td>
			<td>91150-20</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Student surgical scissors</td>
			<td>Fine Science Tools</td>
			<td>91400-14</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Superfros Plus Gold Slides</td>
			<td>Thermo Scientific, USA</td>
			<td>FT4981GLPLUS</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Surgical microscope</td>
			<td>Leica, France</td>
			<td>M320-F12</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Tissue embedding cassettes</td>
			<td>Simport, Canada</td>
			<td>M490-10</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Tissue embedding medium</td>
			<td>LeicaBiosystems, USA</td>
			<td>39602004</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Toluene</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>244511</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;width:328px;">Tricaine MS-222</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>A5040</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Triton X100</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>X100-500 mL</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Vectashield medium&#160;</td>
			<td>Vector Laboratories, USA</td>
			<td>H-1000</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Xylene</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>534056</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Fish Strain</td>
			<td>AB</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Saline phosphate buffer (10X PBS) pH 7.4 (for 1 liter)</td>
			<td></td>
			<td></td>
			<td>For preparing 10X PBS, add the following&#160; salts and complete to 1 liter with distilled water</td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Potassium chloride (MM : 74.55 g/mol): 2.00 g</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>746436</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Potassium phosphate monobasic (MM: 136,09 g/mol): 2.40g</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>795488</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Sodium chloride (MM : 58.44 g/mol): 80.00 g&#160;</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>S9888</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Sodium phosphate dibasic (MM: 141,96 g): 14,40 g</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>795410</td>
			<td></td>
		</tr>
	</tbody>
</table>

acute and chronic models of hyperglycemia in zebrafish: a method to assess the impact of hyperglycemia on neurogenesis and the biodistribution of radiolabeled molecules

Hyperglycemia is a major health issue that leads to cardiovascular and cerebral dysfunction. For instance, it is associated with increased neurological problems after stroke and is shown to impair neurogenic processes. Interestingly, the adult zebrafish has recently emerged as a relevant and useful model to mimic hyperglycemia/diabetes and to investigate constitutive and regenerative neurogenesis. This work provides methods to develop zebrafish models of hyperglycemia to explore the impact of hyperglycemia on brain cell proliferation under homeostatic and brain repair conditions. Acute hyperglycemia is established using the intraperitoneal injection of D-glucose (2.5 g/kg bodyweight) into adult zebrafish. Chronic hyperglycemia is induced by immersing adult zebrafish in D-glucose (111 mM) containing water for 14 days. Blood-glucose-level measurements are described for these different approaches. Methods to investigate the impact of hyperglycemia on constitutive and regenerative neurogenesis, by describing the mechanical injury of the telencephalon, dissecting the brain, paraffin embedding and sectioning with a microtome, and performing immunohistochemistry procedures, are demonstrated. Finally, the method of using zebrafish as a relevant model for studying the biodistribution of radiolabeled molecules (here,[18F]-FDG) using PET/CT is also described.

Using the procedures described in this article, the intraperitoneal injection of D-glucose (2.5 g/kg bodyweight) was performed on adult zebrafish and led to a significant increase in blood glucose levels 1.5 h after injection (Figure 1A). 24 h post-injection, the blood glucose levels were similar between D-glucose and PBS-injected fish12. For chronic treatment, zebrafish were immersed in D-glucose water (111 mM) and became hyperglycemi...

Watch this Scientific Journal Video about Acute and Chronic Models of Hyperglycemia in Zebrafish: A Method to Assess the Impact of Hyperglycemia on Neurogenesis and the Biodistribution of Radiolabeled

Acute and Chronic Models of Hyperglycemia in Zebrafish: A Method to Assess the Impact of Hyperglycemia on Neurogenesis and the Biodistribution of Radiolabeled Molecules

This work describes methods to establish acute and chronic hyperglycemia models in zebrafish. The aim is to investigate the impact of hyperglycemia on physiological processes, such as constitutive and injury-induced neurogenesis. The work also highlights the use of zebrafish to follow radiolabeled molecules (here, [18F]-FDG) using PET/CT.

Hyperglycemia is a major health issue that leads to cardiovascular and cerebral dysfunction. For instance, it is associated with increased neurological ...

The overall goal of the following procedure is to assess brain remodeling in hyperglycemic conditions, and to follow radio-labeled molecules in zebrafish. Hyperglycemia is characterized by an excessive concentration of blood glucose. Chronic hyperglycemia may be due to diabetic conditions, and causes different vascular dysfunctions, that may in turn trigger clinical complications, such as myocardial infarction, stroke, or diabetic foot ulcers.Also, acute hyperglycemia due to stress may promote hemorrhagic complications in ischemic stroke. Zebrafish is an interesting model for understanding human diseases, and their impact on the central nervous system. It is particularly true, given that the brain of adult fish displays an intense neurogenic capacity, and an outstanding capability for brain repair mechanisms, compared to mammals, therefore, zebrafish represent good model for investigating brain remodeling, following stress under acute and hyperglycemic conditions.It also allows investigating the biodistribution of radio-labeled molecules, and potential therapeutic agents. All experiments were conducted in accordance with the French and European community guidelines for the use of animals in research, and approved by the local ethics committee for animal experimentation. Catch a fish gently with a fish net.Put the fish in a small volume of tricaine anesthetic, diluted at a final concentration of 0.02%in the water. Wait until the fish stops moving. Remove the fish, using a cut pipette, and place it gently on absorbent tissue paper to remove a maximum of water.Weigh the fish in order to prepare a syringe of d-glucose for injection, of 50 microliters of 2.5 grams per kilo of body weight. For instance, a 0.6 gram fish will receive 50 microliters of a 3%d-glucose PBS solution. Put the fish on its back, and maintain it with one hand.With the other hand, insert the needle of the syringe in the intraperitoneal cavity, and slowly inject the d-glucose PBS solution. Remove the needle, and put the fish back into the fish water. Check the fish until it recovers completely.Their blood glucose levels are usually measured after 1 1/2 hours. In order to mimic chronic hyperglycemia, prepare a two liter tank of d-glucose, at a final concentration of 111 millimolar. For this, weigh 40 grams of d-glucose, and put it in an empty tank.Fill the tank with two liters of fish water, and place up to seven fish in it. Change the glucose solution every two days, in order to avoid growth of bacteria, or other microorganisms. Chronic hyperglycemia is obtained by a 14 day treatment with d-glucose.Catch a fish with a fish net, and put it on ice. Cover the fish with ice for a rapid euthanasia. Take the fish and wipe it, in order to remove any drops of water that could dilute blood samples.Remove an eye with dissecting forceps, and wait until the eye cavity is filled with blood. Put a test strip on the glucometer, and insert the strip into the eye cavity. Note the value of the blood glucose concentration.For acute hyperglycemia, an intraperitoneal injection of d-glucose induces a significant increase in blood glucose levels, as shown, 1 1/2 hours after injection. For chronic hyperglycemia, immersion of fish in a d-glucose solution results in a significant increase in blood glucose levels, as shown after 14 days of treatment. At the end of the procedure, separate the body from the head with dissecting scissors, and put the head in 4%of paraformaldehyde, diluted in PBS for immunohistochemistry experiments.Incubate overnight at four degrees celsius. Alternatively, the brain can be directly extracted, and frozen for other experiments, such as mRNA extraction. The next day, fixed heads are rinsed with PBS, and maintained with a needle under a dissecting microscope.The remaining eye is removed, and the top of the skull is gently opened with forceps. The brain is then carefully extracted, and placed in 1x PBS. Fixed brains are dehydrated stepwise, in a series of increasing ethanol concentrations, followed by two 30 minute baths of toluene.Brains are then placed in an embedding cassette, and the lid is carefully closed. Put the cassette in melted paraffin, at 58 to 60 degrees celsius. During paraffin embedding of the brain, turn on the warming inclusion forceps.Put the cassette into a clean paraffin bath. At the end of the paraffin baths, take out the cassette. Pour some liquid paraffin into a mold.Open the cassette, and place the brain within melted paraffin in the mold. Orientate the brain with the warming inclusion forceps. Fill up the mold with melted paraffin, and let it harden on the cooling part of the embedding machine.For technical reasons, brain should be positioned according to an anterior-posterior axis. After unmolding the paraffin block, crop it, and fix it on a cassette with melted paraffin, in the right orientation to allow transversal sectioning. Insert the paraffin block in the arm of a microtome, and cut 50 micrometer sections, until reaching the brain sample level.Then, trim the paraffin block to obtain a trapeze, and adjust the sectioning thickness to seven micrometers. Collect the paraffin ribbons with a fine paint brush, and put it on a black paper. Cut the paraffin ribbons every three to four sections.Put a slide on a warming plate, and cover it with distilled water. Position gently the sections on the water on the slide, and warm up to 40 degrees celsius. When paraffin ribbons are sufficiently spread, remove the water with absorbent tissue.The last drops are mechanically removed, as shown. Let the slide dry at least two hours before performing the immunohistochemistry procedure described in the protocol. After immunohistochemistry, the slides are analyzed under an epifluorescence, or a confocal, microscope, for studying the impact of hyperglycemia on brain cell proliferation.Brain cell quantification is made on at least three successive sections, or a region of interest. Here, proliferative cells corresponding to PCNA positive cells appear in green. As you can see, chronic hyperglycemia induces a decrease in the number of proliferative cells, labeled in green with PCNA antibody, in the ventral telencephalon, the dorsal telencephalon, and the caudal hypothalamus, around the lateral and posterior recess.Alternatively, for studying the effects of hyperglycemia on injury induced neurogenesis, a stab wound injury of the telencephalon can be performed during chronic hyperglycemic treatment. For this, anesthetize a seven day treated fish, and put it under a dissecting microscope. Push a 30 gauge syringe vertically through the skull, into the center of the right telencephalic hemisphere.After this procedure, the fish should be returned to its tank for the required time. Here, the fish was allowed to survive seven days in d-glucose water, before being sacrificed. Stab wound injury of the telencephalon strongly upregulates proliferation in the injured hemisphere, seven days post-lesion.Our data show that chronic hyperglycemia induces a significant decrease in brain healing processes, by decreasing cell proliferation after stab wound injury of the telencephalon. Zebrafish can also be used for studying the biodistribution of radio-labeled molecules. Here, we decided to study glucose metabolism in the zebrafish organism.The fish should be first anesthetized, and placed on a tissue soaked with anesthetics. The fish is then placed behind a radio protection window. The syringe containing 50 microliters of fluorodeoxyglucose is prepared.The fish is positioned on its back, and injected intraperitoneally with 50 microliters of FDG at 20 megabecquerel. The fish is then placed on another tissue soaked with anesthetics. It is gently wrapped, and the positioned on the arm of a PET scan imager.The arm is inserted into the PET scan, and the imaging procedure is performed. Here, you can note that FDG is not only detected at the injection site, but also in the head of the fish, notably, in the brain, and all along the spinal cord. In this study, we provide two different methods for establishing acute and chronic hyperglycemia in zebrafish, and we show that hyperglycemia impairs brain cell proliferation under normal and injury induced conditions.In conclusion, zebrafish can be used as a relevant model to investigate the deleterious effects of hyperglycemia in the central nervous system. It also allows assessing the biodistribution of radio-labeled molecules by PET scan.

acute-chronic-models-hyperglycemia-zebrafish-method-to-assess-impact

Research

JoVE Journal

Developmental Biology

13.3K vues.  Université de La Réunion, INSERM. The overall goal of the following procedure is to assess brain remodeling in hyperglycemic conditions, and to follow radio-labeled molecules in zebrafish. Hyperglycemia is characterized by an excessive concentration of blood glucose. Chronic hyperglycemia may be due to diabetic conditions, and causes different vascular dysfunctions, that may in turn trigger clinical complications, such as myocardial infarction, stroke, or diabetic foot ulcers.Also, acute hyperglycemia due to stress may...

Vidéo: Acute and Chronic Models of Hyperglycemia in Zebrafish: A Method to Assess the Impact of Hyperglycemia on Neurogenesis and the Biodistribution of Radiolabeled Molecules