Este trabalho foi financiado pela Neuro-Bio Ltd. Gostaríamos de agradecer ao Dr. Giovanni Ferrati e Dr. Sergio Rotondo (Neuro-Bio) para seus comentários e conselhos sobre o manuscrito.

Todos os estudos em animais foram realizados sob protocolos aprovados.
Nota: Nesta seção, a sequência das principais fases executadas durante o procedimento experimental e o intervalo de tempo sugerido é fornecido (Figura 1). Além disso, uma descrição passo a passo do protocolo é complementada por um painel ilustrativo, mostrando ações críticas que variam de remoção do cérebro a homogeneização do tecido após o período de incubação (Figura 2). Os detalhes sobre os materiais e instruções para construir o aparelho e a fase subsequente para a análise de WB são descritas anteriormente22.
1. cirúrgicas ferramentas, configurações de Vibratome e preparação de tratamento
Nota: Execute as etapas a seguir antes de iniciar o procedimento experimental:
<ol><li>Prepare dois diferentes artificiais cerebrospinal fluidos (aCSFs), que usou para cortar o cérebro e o outro para a etapa de incubação como descrito anteriormente29. Brevemente, as concentrações de trabalho (em mmol) dos dois aCSFs são para o "fatiar" aCSF: 120 NaCl, 5 KCl, 20 NaHCO3, 2.4 CaCl2, 2 MgSO4, 1.2 KH2PO4e 10 glicose; 6.7 HEPES sal e ácido HEPES 3.3; pH: 7.1. Tempo para a "gravação" aCSF: 124 NaCl, 3.7 KCl, 26 NaHCO3, 2 CaCl2, 1.3 MgSO4, 1.3 KH2PO4e 10 glicose; pH: 7.1.</li>
	<li>Misture bem as soluções e colocar no gelo e oxigenar a aCSF corte a fim de tê-lo frio ao remover o cérebro e o seccionamento subsequentes. Manter a temperatura (RT) e fornecimento de oxigênio para a aCSF de gravação.</li>
	<li>Coloque os instrumentos sob a capa de dissecação para a remoção de decapitação e cérebro, ou seja, guilhotina, kit cirúrgico de dissecação (tesouras, pinças, lâminas) e espátula.</li>
	<li>Configure os parâmetros de vibratome, selecionando a espessura da fatia (300 µm nesta preparação) e a frequência às 7 e a velocidade em 6. Inserir a câmara de vibratome no seu espaço apropriado e cercá-lo com gelo.</li>
	<li>Abra a válvula de carbogênio (95% O2, 5% CO2) para oxigenar o "corte" (aCSF) durante o corte do cérebro. Selecione a taxa de vazão mínima, em torno de 2 mL/min.</li>
	<li>Pegue dois tubos de 15 mL para preparar as condições para testar. Adicione em um tubo de 10 mL da "gravação" aCSF sozinho (grupo controle) e no outro, 10 mL da "gravação" aCSF enriquecido com T30 em uma concentração de 2 µM (grupo tratado). Vórtice tanto tubos e mantê-los no gelo até sua utilização na fase de preparação de instalação (secção 3).</li>
</ol>2. anestesia, extração de cérebro e de corte
Nota: Neste estudo, foram usados 9 tipo selvagem P14 ratos machos Wistar. Extração do cérebro e subsequente corte constituem uma parte crítica do protocolo, desde que eles devem ser realizados rapidamente (dentro de 10 min) a fim de evitar ou pelo menos abrandar os processos de degeneração do tecido.
<ol><li>Adicione 1,5 mL de 100% w/w de isoflurano em uma camada de algodão para a câmara de indução, colocar o animal dentro e feche a tampa. Espere até que o animal é anestesiado profundamente, confirmando a ausência do pedal reflexo e então decapitar o animal usando a guilhotina.</li>
	<li>Mantenha a cabeça do animal dentro de um pote contendo gelada corte aCSF durante a etapa de remoção do cérebro (Figura 2A -C).</li>
	<li>Faça uma incisão na pele sobre o crânio com uma lâmina cirúrgica, em seguida, recorte usando a tesoura, seguindo a linha mediana, desde a parte posterior do crânio e proceda anteriormente até atingir o osso acima do OBs (Figura 2A).</li>
	<li>Puxe lateralmente os dois lados do crânio usando um par de pinças para poder ter acesso ao cérebro (Figura 2B). Insira uma espátula ventralmente ao cérebro, colher-se suavemente para fora e mantê-lo hidratado na gelada aCSF "fatiar" por aproximadamente 5 min (Figura 2).</li>
	<li>Elimine o cérebro no filtro de papel e cortar o cerebelo usando uma lâmina (Figura 2D). Cola o cérebro verticalmente sobre o disco de vibratome e inseri-lo no interior da câmara de corte, preenchê-lo com aCSF "fatiar" gelada e fornecer oxigênio (Figura 2E).</li>
	<li>Ajustar o intervalo de corte e prosseguir com o seccionamento do cérebro (Figura 2F). Recolha as seções que contém a região de interesse, tais como o septo medial (MS), a banda diagonal de Broca (DBB) e substância innominata (SI), como descrito anteriormente,22. De cima para baixo, as três fatias contêm o rostral (R), intermediário (I) e caudal (C) parte do BF (Figura 2).</li>
	<li>Dividir ao longo da linha mediana de cada seção com uma pequena tesoura, obtendo dois hemislices especulares (Figura 2 H), usado individualmente como o controle e a condição tratada no mesmo plano anatômico.</li>
	<li>Manter o hemisections na câmara de vibratome por 5-10 min, em seguida, transferi-los com uma pipeta de vidro em um subida pote contendo gravação aCSF. Mantenha a RT para cerca de 30 min para recuperar.</li>
	<li>Preencha, entretanto, três frascos de vidro com 3 ml de solução de gravação aCSF sozinho (anteriormente na etapa 1.6 para o grupo de controle) e três tubos de ensaio com 3 mL de aCSF enriquecido com T30 (previamente preparado no passo 1.6) para o grupo tratado.</li>
</ol>3. preparação da instalação
<ol><li>Transferir o hemisections para seus frascos de vidro correspondente (Figura 2I) a fim de ter três hemislices consecutivos (incluindo a região BF rostral, intermediária e caudal) para o grupo de controle (quadro verde, Figura 2J) e suas correspondência de contrapartes para o grupo tratado (quadro vermelho, Figura 2J).</li>
	<li>Transferi o tecido cerebral com duas escovas diferentes, uma para o controle hemislices e outro para as contrapartes tratadas, para evitar qualquer contaminação entre as condições.</li>
	<li>Sele cada frasco de vidro com a tampa correspondente, apresentando a agulha oxigenação (21G) (Figura 2J). Ligar o tubo principal do aparelho para a fonte de carbogênio (Figura 2 K). Entrega oxigênio para a hemislices durante todo o período de incubação com um caudal mínimo de 2 mL/min para evitar qualquer movimento do tecido cerebral e possíveis danos mecânicos durante o experimento. Inicie a incubação de 5h. Execute as etapas de 3.1-3.3 dentro de 5 min. Nota: Verifique frequentemente (cada 15-20 min) se o oxigênio é fornecido em todos os frascos e que seu fluxo não está se movendo o tecido do fundo.</li>
</ol>4. homogeneização da amostra
<ol><li>Parar o fluxo de oxigênio após a incubação e remover todas as tampas dos frascos. Transferi o hemislices, usando os pincéis adequados, para tubos de 1,5 mL, contendo 250 µ l de tampão de Lise, manter os tubos em gelo (Figura 2 L). Para fazer a lise de tampão, misturar PBS 1 x com cocktails de inibidores da fosfatase e protease tanto diluído a 1: 100 e homogeneizar o tecido com macacos diferentes para evitar a contaminação entre as amostras. Conclua essas ações dentro de 10-15 min.</li>
	<li>Centrifugue o cérebro lisado a 1.000 x g por 5 min a 4 ° C. Transferir o sobrenadante para tubos novos e manter as amostras a-80 ° C.</li>
</ol>5. leitura da concentração de proteínas e análise ocidental do borrão
<ol><li>Determinar a concentração de proteína de cada amostra e posteriormente, preparar as alíquotas para análise ocidental do borrão como descrito anteriormente,22.</li>
	<li>Realizar análise estatística para avaliar os efeitos do tratamento na expressão da proteína.</li>
</ol>

<ol>
	<li>Braak, H., Braak, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropathological+stageing+of+Alzheimer-related+changes.">Neuropathological stageing of Alzheimer-related changes.</a> Acta Neuropathologica. 82 (4), 239-259 (1991).</li><li>Schliebs, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basal+forebrain+cholinergic+dysfunction+in+Alzheimer's+disease--interrelationship+with+beta-amyloid,+inflammation+and+neurotrophin+signaling.">Basal forebrain cholinergic dysfunction in Alzheimer's disease--interrelationship with beta-amyloid, inflammation and neurotrophin signaling.</a> Neurochemical Research. 30 (6-7), 895-908 (2005).</li><li>Schmitz, T. 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=Basal+forebrain+degeneration+precedes+and+predicts+the+cortical+spread+of+Alzheimer's+pathology.">Basal forebrain degeneration precedes and predicts the cortical spread of Alzheimer's pathology.</a> Nature Communications. 7, 13249 (2016).</li><li>Fjell, A. M., McEvoy, L., Holland, D., Dale, A. M., Walhovd, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+is+normal+in+normal+aging?+Effects+of+aging,+amyloid+and+Alzheimer's+disease+on+the+cerebral+cortex+and+the+hippocampus.">What is normal in normal aging? Effects of aging, amyloid and Alzheimer's disease on the cerebral cortex and the hippocampus.</a> Progress in neurobiology. 117, 20-40 (2014).</li><li>Kov&#225;cs, T., Cairns, N. J., Lantos, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olfactory+centres+in+Alzheimer's+disease:+olfactory+bulb+is+involved+in+early+Braak's+stages.">Olfactory centres in Alzheimer's disease: olfactory bulb is involved in early Braak's stages.</a> Neuroreport. 12 (2), 285-288 (2001).</li><li>Winblad, 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=Defeating+Alzheimer's+disease+and+other+dementias:+a+priority+for+European+science+and+society.">Defeating Alzheimer's disease and other dementias: a priority for European science and society.</a> The Lancet Neurology. 15 (5), 455-532 (2016).</li><li>Herrup, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+case+for+rejecting+the+amyloid+cascade+hypothesis.">The case for rejecting the amyloid cascade hypothesis.</a> Nat Neurosci. 18 (6), 794-799 (2015).</li><li>De Strooper, B., Karran, E. <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+Phase+of+Alzheimer's+Disease.">The Cellular Phase of Alzheimer's Disease.</a> Cell. 164 (4), 603-615 (2016).</li><li>Scheltens, 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=Alzheimer's+disease.">Alzheimer's disease.</a> Lancet. 388 (10043), 505-517 (2016).</li><li>Arendt, T., Br&#252;ckner, M. K., Lange, M., Bigl, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+acetylcholinesterase+and+butyrylcholinesterase+in+Alzheimer's+disease+resemble+embryonic+development-A+study+of+molecular+forms.">Changes in acetylcholinesterase and butyrylcholinesterase in Alzheimer's disease resemble embryonic development-A study of molecular forms.</a> Neurochemistry International. 21 (3), 381-396 (1992).</li><li>Auld, D. S., Kornecook, T. J., Bastianetto, S., Quirion, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alzheimer's+disease+and+the+basal+forebrain+cholinergic+system:+relations+to+&#946;-amyloid+peptides,+cognition,+and+treatment+strategies.">Alzheimer's disease and the basal forebrain cholinergic system: relations to &#946;-amyloid peptides, cognition, and treatment strategies.</a> Progress in Neurobiology. 68 (3), 209-245 (2002).</li><li>Arendt, T., Bruckner, M. K., Morawski, M., Jager, C., Gertz, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+neurone+loss+in+Alzheimer's+disease:+cortical+or+subcortical?.">Early neurone loss in Alzheimer's disease: cortical or subcortical?.</a> Acta Neuropathol Commun. 3, 10 (2015).</li><li>Mesulam, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Cholinergic+Lesion+of+Alzheimer's+Disease:+Pivotal+Factor+or+The+Cholinergic+Lesion+of+Alzheimer's+Disease:+Pivotal+Factor+or+Side+Show?.">The Cholinergic Lesion of Alzheimer's Disease: Pivotal Factor or The Cholinergic Lesion of Alzheimer's Disease: Pivotal Factor or Side Show?.</a> Learn Mem. , 43-49 (2004).</li><li>Schliebs, R., Arendt, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cholinergic+system+in+aging+and+neuronal+degeneration.">The cholinergic system in aging and neuronal degeneration.</a> Behavioural Brain Research. 221 (2), 555-563 (2011).</li><li>Mesulam, M. M., Mufson, E. J., Wainer, B. H., Levey, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+cholinergic+pathways+in+the+rat:+An+overview+based+on+an+alternative+nomenclature+(Ch1-Ch6).">Central cholinergic pathways in the rat: An overview based on an alternative nomenclature (Ch1-Ch6).</a> Neuroscience. 10 (4), 1185-1201 (1983).</li><li>Mesulam, M., Mufson, E. J., Levey, A. I., Wainer, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholinergic+innervation+of+cortex+by+the+basal+forebrain:+cytochemistry+and+cortical+connections+of+the+septal+area,+diagonal+band+nuclei,+nucleus+basalis+(substantia+innominata),+and+hypothalamus+in+the+rhesus+monkey.">Cholinergic innervation of cortex by the basal forebrain: cytochemistry and cortical connections of the septal area, diagonal band nuclei, nucleus basalis (substantia innominata), and hypothalamus in the rhesus monkey.</a> J Comp Neurol. 214 (2), 170-197 (1983).</li><li>Greenfield, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovering+and+targeting+the+basic+mechanism+of+neurodegeneration:+The+role+of+peptides+from+the+C-terminus+of+acetylcholinesterase:+Non-hydrolytic+effects+of+ache:+The+actions+of+peptides+derived+from+the+C-terminal+and+their+relevance+to+neurodegenerat.">Discovering and targeting the basic mechanism of neurodegeneration: The role of peptides from the C-terminus of acetylcholinesterase: Non-hydrolytic effects of ache: The actions of peptides derived from the C-terminal and their relevance to neurodegenerat.</a> Chemico-Biological Interactions. 203 (3), 543-546 (2013).</li><li>Garcia-Rat&#233;s, 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=(I)+Pharmacological+profiling+of+a+novel+modulator+of+the+&#945;7+nicotinic+receptor:+Blockade+of+a+toxic+acetylcholinesterase-derived+peptide+increased+in+Alzheimer+brains.">(I) Pharmacological profiling of a novel modulator of the &#945;7 nicotinic receptor: Blockade of a toxic acetylcholinesterase-derived peptide increased in Alzheimer brains.</a> Neuropharmacology. 105, 487-499 (2016).</li><li>Eimerl, S., Schramm, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+quantity+of+calcium+that+appears+to+induce+neuronal+death.">The quantity of calcium that appears to induce neuronal death.</a> Journal of neurochemistry. 62 (3), 1223-1226 (1994).</li><li>Greenfield, S., Vaux, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commentary+Parkinson's+Disease,+Alzheimer's+Disease+and+Motor+Neurone+Disease:+Identifying+a+Common+Mechanism.">Commentary Parkinson's Disease, Alzheimer's Disease and Motor Neurone Disease: Identifying a Common Mechanism.</a> Science. 113 (3), 485-492 (2002).</li><li>Badin, A. S., Morrill, P., Devonshire, I. M., Greenfield, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=(II)+Physiological+profiling+of+an+endogenous+peptide+in+the+basal+forebrain:+Age-related+bioactivity+and+blockade+with+a+novel+modulator.">(II) Physiological profiling of an endogenous peptide in the basal forebrain: Age-related bioactivity and blockade with a novel modulator.</a> Neuropharmacology. 105, 47-60 (2016).</li><li>Brai, E., Stuart, S., Badin, A. -. S., Greenfield, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Novel+Ex+Vivo+Model+to+Investigate+the+Underlying+Mechanisms+in+Alzheimer's+Disease.">A Novel Ex Vivo Model to Investigate the Underlying Mechanisms in Alzheimer's Disease.</a> Frontiers in Cellular Neuroscience. 11, 291 (2017).</li><li>Cho, S., Wood, A., Bowlby, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+slices+as+models+for+neurodegenerative+disease+and+screening+platforms+to+identify+novel+therapeutics.">Brain slices as models for neurodegenerative disease and screening platforms to identify novel therapeutics.</a> Current neuropharmacology. 5 (1), 19-33 (2007).</li><li>Humpel, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organotypic+brain+slice+cultures:+A+review.">Organotypic brain slice cultures: A review.</a> Neuroscience. 305, 86-98 (2015).</li><li>Sakmann, B., Neher, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patch+clamp+techniques+for+studying+ionic+channels+in+excitable+membranes.">Patch clamp techniques for studying ionic channels in excitable membranes.</a> Annual review of physiology. 46, 455-472 (1984).</li><li>Jensen, M. S., Lambert, J. D. C., Johansen, F. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+recordings+from+rat+hippocampus+slices+following+in+vivo+brain+ischemia.">Electrophysiological recordings from rat hippocampus slices following in vivo brain ischemia.</a> Brain Research. 554 (1-2), 166-175 (1991).</li><li>Ferrati, G., Martini, F. J., Maravall, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+Adenosine+Receptor-Mediated+Regulation+of+Diverse+Thalamocortical+Short-Term+Plasticity+in+the+Mouse+Whisker+Pathway.">Presynaptic Adenosine Receptor-Mediated Regulation of Diverse Thalamocortical Short-Term Plasticity in the Mouse Whisker Pathway.</a> Frontiers in Neural Circuits. 10, 1-9 (2016).</li><li>Grinvald, A., Hildesheim, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VSDI:+a+new+era+in+functional+imaging+of+cortical+dynamics.">VSDI: a new era in functional imaging of cortical dynamics.</a> Nature Reviews Neuroscience. 5 (11), 874-885 (2004).</li><li>Badin, A. S., John, E., Susan, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+spatio-temporal+bioactivity+of+a+novel+peptide+revealed+by+optical+imaging+in+rat+orbitofrontal+cortex+in+vitro:+Possible+implications+for+neurodegenerative+diseases.">High-resolution spatio-temporal bioactivity of a novel peptide revealed by optical imaging in rat orbitofrontal cortex in vitro: Possible implications for neurodegenerative diseases.</a> Neuropharmacology. 73, 10-18 (2013).</li><li>Greenfield, S. A., Badin, A. S., Ferrati, G., Devonshire, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+imaging+of+the+rat+brain+suggests+a+previously+missing+link+between+top-down+and+bottom-up+nervous+system+function.">Optical imaging of the rat brain suggests a previously missing link between top-down and bottom-up nervous system function.</a> Neurophotonics. 4, 31213 (2017).</li><li>Opitz-Araya, X., Barria, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organotypic+hippocampal+slice+cultures.">Organotypic hippocampal slice cultures.</a> Journal of visualized experiments: JoVE. (48), (2011).</li><li>Gong, C. -. X., Lidsky, T., Wegiel, J., Grundke-Iqbal, I., Iqbal, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolically+active+rat+brain+slices+as+a+model+to+study+the+regulation+of+protein+phosphorylation+in+mammalian+brain.">Metabolically active rat brain slices as a model to study the regulation of protein phosphorylation in mammalian brain.</a> Brain Research Protocols. 6 (3), 134-140 (2001).</li></ol>

Os autores declaram concorrentes interesses financeiros. Susan A. Greenfield é o fundador e presidente da Neuro-Bio Limited, uma empresa canadense e detém ações da empresa. Emanuele Brai e Antonella Cogoni são empregados da Neuro-Bio Ltd.

O principal aspecto do presente protocolo, baseado na técnica cérebro bem-estabelecida ex vivo , permite testar sincronicamente duas hemislices especulares, obtidas no mesmo plano anatômico, monitorando sua resposta após a aplicação de um determinado condição (controlar ou tratados); Este, portanto, oferece uma paradigma experimental tão rigidamente controlada quanto possível. A possibilidade de avaliar em um tempo - dose- e site-specific maneira diferente neuroquímicos relacionados com comprometiment...

AD é que uma patologia crônica caracterizada por imparidade neurodegenerativa progressiva, afetando áreas diferentes do cérebro, tais como o córtex entorhinal (CE), BF, hipocampo (HC) e bulbo olfatório (OB)1,2,3, 4,5. Estágios finais de desenvolvimento AD conduzem a um progressivo declínio cognitivo, tornando esta doença, a forma mais comum de demência, representando aproximadamente 70% de todos os casos6. Apesar das tentativas extensas para entender os estágios iniciais, causando AD, não há atualmente uma indicação experimental definida elucidá-los. Além disso, a teoria mais popular - a "hipótese amiloide" - é cada vez mais questionada desde que ele não fornece um perfil completo em explicar o Patobiológico AD, nem um alvo farmacêutico que se revelou eficaz7,8 ,9.
Uma teoria alternativa que está recebendo atenção crescente sugere que os mecanismos iniciais ocorrem durante neurodegeneração estão relacionados a um cluster neuronal principalmente sensível no AD3,10,11 , 12 , 13 , 14. este hub celular heterogênea englobada no âmbito dos projectos BF, mesencéfalo e tronco cerebral, para várias regiões, tais como o CE, HC e OB15,16. Apesar de sua diversidade na morfologia neuronal e síntese de neurotransmissor, esse núcleo de células compartilha uma característica comum em expressar a dor, que também pode ter uma função não-enzimática de17,18. Este papel não-clássica como um romance de sinalização molécula Medeia o fluxo de cálcio (Ca2 +) em neurônios que pode passar por eventos tróficos ou tóxicos em relação à dose de Ca2 + , disponibilidade e idade neuronal17,18 , 19.
Durante neurodegeneração, a perda celular observada pode ser, portanto, associada a esta função não enzimáticos17,18,20, que é atribuível a um peptídeo 30mer (T30) clivado de dor C-terminal 20. em consonância com os resultados anteriores, realizados na cultura de pilha e óptico de imagem18,21 preparações, temos demonstrado, através de uma nova abordagem baseada em ex vivo fatias cérebro rato contendo estruturas BF, que induziu T30 um perfil AD22. Especificamente, esta nova metodologia oferece um cenário mais fisiológico do que cultura celular desde que ele mantém muitas das características de um tecido intacto, variando de anatômica para preservação de circuitos, embora para uma janela de tempo de horas. Aplicamos este protocolo para explorar os eventos que ocorrem durante as primeiras fases de neurodegeneração, monitoramento da resposta aguda a T30 pedido.
Apesar da grande corpus de literatura sobre o uso do cérebro fatias para investigar as vias moleculares implícita no dano neuronal ou neurogênese23,24, este protocolo fornece pela primeira vez uma mais imediata e sensível à leitura comparada para o uso comum de organotypic fatias. No entanto, como é o caso de organotypic seções do cérebro, este procedimento de fatia aguda pode também ser adotado para fins diversos, tais como a avaliação de neuroprotective ou moléculas neurotóxicas, descoberta de mudanças moleculares primárias que ocorrem em um processo específico, a análise imuno-histoquímica e ensaios farmacológicos para o sistema nervoso central relacionadas com patologias.

<table>
	<tbody>
		<tr>
			<td>Sodium chloride (NaCl)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>S7653</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Potassium chloride (KCl)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>P9333</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate (NaHCO3)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>S5761</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Magnesium sulphate heptahydrate (MgSO4 (7H2O))</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>63138</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Potassium phosphate monobasic (KH2PO4)</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>P5655</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Hepes salt</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>H7006</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Hepes acid</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>H3375</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>G7528</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>Calcium chloride dehydrate</td>
			<td>Sigma-Aldrich, Germany</td>
			<td>223506</td>
			<td>Reagent for aCSF preparation</td>
		</tr>
		<tr>
			<td>T30 peptide</td>
			<td>Genosphere Biotechnologies, France</td>
			<td></td>
			<td>AChE-derived peptide tested</td>
		</tr>
		<tr>
			<td>Surgical dissecting kit</td>
			<td>World Precision Instruments, USA</td>
			<td>Item #: MOUSEKIT</td>
			<td>Brain removal step</td>
		</tr>
		<tr>
			<td>Surgical blades</td>
			<td>Swann-Morton, UK</td>
			<td>BS 2982</td>
			<td>Brain removal step</td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>Fisher Scientific, USA</td>
			<td>11566873</td>
			<td>Brain preparation for slicing</td>
		</tr>
		<tr>
			<td>Glue</td>
			<td></td>
			<td></td>
			<td>Brain preparation for slicing</td>
		</tr>
		<tr>
			<td>Vibratome</td>
			<td>Leica, Germany</td>
			<td>VT1000 S</td>
			<td>Slicing</td>
		</tr>
		<tr>
			<td>Brushes</td>
			<td></td>
			<td></td>
			<td>Tissue handling</td>
		</tr>
		<tr>
			<td>Oxygen canister</td>
			<td></td>
			<td></td>
			<td>Sectioning and incubation phase</td>
		</tr>
		<tr>
			<td>1x Phosphate buffer saline (PBS)</td>
			<td>Fisher Scientific, USA</td>
			<td>BP2438-4</td>
			<td>Homogenization step</td>
		</tr>
		<tr>
			<td>Phosphatase inhibitors</td>
			<td>Fisher Scientific, USA</td>
			<td>1284-1650</td>
			<td>Homogenization step</td>
		</tr>
		<tr>
			<td>Protease inhibitors</td>
			<td>Roche complete PIC, USA</td>
			<td>4693116001</td>
			<td>Homogenization step</td>
		</tr>
		<tr>
			<td>Pestles</td>
			<td>Starlab, UK</td>
			<td>I1415-5390</td>
			<td>Homogenization step</td>
		</tr>
		<tr>
			<td>Microcentrifuge</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pierce 660 nm Protein Assay</td>
			<td>Thermo Scientific, USA</td>
			<td>22660</td>
			<td>Protein concentration</td>
		</tr>
	</tbody>
</table>

an alternative approach to study primary events in neurodegeneration using ex vivo rat brain slices

Apesar de numerosos estudos que tentam desenvolver modelos animais confiáveis que refletir o primário processa neurodegeneração subjacente, muito poucos foram amplamente aceites. Aqui, propomos um novo procedimento adaptado de conhecidos ex vivo cérebro fatia técnica, que oferece um mais perto na vivo-como cenário do que em vitro preparações para investigar os eventos iniciais provocando degeneração celular, como observada na doença de Alzheimer (AD). Esta variação consiste em etapas simples e facilmente reproduzíveis, que permitem a preservação do cytoarchitecture anatômica da região selecionada do cérebro e sua funcionalidade local em um ambiente fisiológico. Diferentes áreas anatômicas podem ser obtidas o mesmo cérebro, proporcionando a oportunidade de realizar várias experiências com os tratamentos em questão em um local-, dose e tempo-dependente. Limitações potenciais que poderiam afetar os resultados relacionados com esta metodologia estão relacionadas com a conservação do tecido, ou seja, a manutenção da sua integridade anatômica durante as etapas de corte e a incubação e a espessura de corte, que pode influenciar a análise bioquímica e imuno-histoquímica. Esta abordagem pode ser utilizada para diferentes fins, tais como explorar mecanismos moleculares envolvidos em condições fisiológicas ou patológicas, triagem de drogas ou ensaios de dose-resposta. Finalmente, este protocolo também poderia reduzir o número de animais utilizados em estudos comportamentais. O aplicativo aqui relatado foi recentemente descrito e testado pela primeira vez na ex vivo fatias cérebro rato contendo o prosencéfalo basal (BF), que é uma das regiões cerebrais afetadas principalmente no AD. Especificamente, foi demonstrado que a administração de um peptídeo tóxico derivado do C-terminal da acetilcolinesterase (AChE) poderia solicitar um AD-como o perfil, provocando, ao longo do eixo antero-posterior do BF, uma expressão diferencial de proteínas alteradas na AD, como o receptor nicotínico alpha7 (α7-nAChR), fosforilada Tau (p-Tau) e beta amiloide (Aβ).

O protocolo aqui apresentado indica que a administração de um peptídeo tóxico, T30, modula de forma local-dependente da expressão do nAChR, α7-p-Tau e Aβ nas seções contendo BF (Figura 3A). O receptor nicotínico mostra um aumento significativo no hemislice rostral-tratados, comparado ao seu homólogo de controle (fatia 1, p = 0.0310) (Figura 3B), enquanto a fatia intermediária não revela qualquer alteração ...

Watch this Scientific Journal Video about An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices at JoVE.com

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

Apresentamos um método que pode fornecer mais insights sobre os primeiros eventos subjacentes a neurodegeneração e baseia a técnica de cérebro estabelecido ex vivo , combinando as vantagens dos experimentos in vivo e in vitro . Além disso, representa uma oportunidade única para comparação directa do grupo tratado e não tratado no mesmo plano anatômico.

Uma abordagem alternativa para estudar eventos primários na neurodegeneração usando fatias de cérebro de rato Ex Vivo

Despite&#160;numerous studies that attempt to develop reliable animal models&#160;which reflecting the primary processes underlying neurodegeneration, ...

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Research

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Neuroscience

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

6.8K visualizações.  Culham Science Centre. Apresentamos um método que pode fornecer mais insights sobre os primeiros eventos subjacentes a neurodegeneração e baseia a técnica de cérebro estabelecido ex vivo , combinando as vantagens dos experimentos in vivo e in vitro . Além disso, representa uma oportunidade única para comparação directa do grupo tratado e não tratado no mesmo plano anatômico.

Vídeo: An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

In vivo Laser Axotomy in C. elegans

Neurons communicate with other cells via axons and dendrites, slender membrane extensions that contain pre- or post-synaptic specializations. If a neuron is damaged by injury or disease, it may regenerate. Cell-intrinsic and extrinsic factors influence the ability of a neuron to regenerate and restore function. Recently, the nematode C. elegans has emerged as an excellent model organism to identify genes and signaling pathways that influence the regeneration of neurons1-6. The main way to initiate neuronal regeneration in C. elegans is laser-mediated cutting, or axotomy. During axotomy, a fluorescently-labeled neuronal process is severed using high-energy pulses. Initially, neuronal regeneration in C. elegans was examined using an amplified femtosecond laser5. However, subsequent regeneration studies have shown that a conventional pulsed laser can be used to accurately sever neurons in vivo and elicit a similar regenerative response1,3,7.
We present a protocol for performing in vivo laser axotomy in the worm using a MicroPoint pulsed laser, a turnkey system that is readily available and that has been widely used for targeted cell ablation. We describe aligning the laser, mounting the worms, cutting specific neurons, and assessing subsequent regeneration. The system provides the ability to cut large numbers of neurons in multiple worms during one experiment. Thus, laser axotomy as described herein is an efficient system for initiating and analyzing the process of regeneration.

In vivo Laser Axotomy in C. elegans

A protocol to cut neurons in C. elegans with a MicroPoint pulsed laser is presented. We describe setting up the system, immobilizing worms, and severing labeled neurons. Advantages include a relatively low-cost system and the ability to sever neuronal processes or ablate cells in vivo.

In vivo Laser axotomia em C. elegans

Neurons communicate with other cells via axons and dendrites, slender membrane extensions that contain pre- or post-synaptic specializations. If a neuron ...

Neurociência

A Rapid Approach to High-Resolution Fluorescence Imaging in Semi-Thick Brain Slices

A fundamental goal to both basic and clinical neuroscience is to better understand the identities, molecular makeup, and patterns of connectivity that are characteristic to neurons in both normal and diseased brain. Towards this, a great deal of effort has been placed on building high-resolution neuroanatomical maps1-3. With the expansion of molecular genetics and advances in light microscopy has come the ability to query not only neuronal morphologies, but also the molecular and cellular makeup of individual neurons and their associated networks4. Major advances in the ability to mark and manipulate neurons through transgenic and gene targeting technologies in the rodent now allow investigators to 'program' neuronal subsets at will5-6. Arguably, one of the most influential contributions to contemporary neuroscience has been the discovery and cloning of genes encoding fluorescent proteins (FPs) in marine invertebrates7-8, alongside their subsequent engineering to yield an ever-expanding toolbox of vital reporters9. Exploiting cell type-specific promoter activity to drive targeted FP expression in discrete neuronal populations now affords neuroanatomical investigation with genetic precision.
Engineering FP expression in neurons has vastly improved our understanding of brain structure and function. However, imaging individual neurons and their associated networks in deep brain tissues, or in three dimensions, has remained a challenge. Due to high lipid content, nervous tissue is rather opaque and exhibits auto fluorescence. These inherent biophysical properties make it difficult to visualize and image fluorescently labelled neurons at high resolution using standard epifluorescent or confocal microscopy beyond depths of tens of microns. To circumvent this challenge investigators often employ serial thin-section imaging and reconstruction methods10, or 2-photon laser scanning microscopy11. Current drawbacks to these approaches are the associated labor-intensive tissue preparation, or cost-prohibitive instrumentation respectively.
Here, we present a relatively rapid and simple method to visualize fluorescently labelled cells in fixed semi-thick mouse brain slices by optical clearing and imaging. In the attached protocol we describe the methods of: 1) fixing brain tissue in situ via intracardial perfusion, 2) dissection and removal of whole brain, 3) stationary brain embedding in agarose, 4) precision semi-thick slice preparation using new vibratome instrumentation, 5) clearing brain tissue through a glycerol gradient, and 6) mounting on glass slides for light microscopy and z-stack reconstruction (Figure 1).
For preparing brain slices we implemented a relatively new piece of instrumentation called the 'Compresstome' VF-200 (http://www.precisionary.com/products_vf200.html). This instrument is a semi-automated microtome equipped with a motorized advance and blade vibration system with features similar in function to other vibratomes. Unlike other vibratomes, the tissue to be sliced is mounted in an agarose plug within a stainless steel cylinder. The tissue is extruded at desired thicknesses from the cylinder, and cut by the forward advancing vibrating blade. The agarose plug/cylinder system allows for reproducible tissue mounting, alignment, and precision cutting. In our hands, the 'Compresstome' yields high quality tissue slices for electrophysiology, immunohistochemistry, and direct fixed-tissue mounting and imaging. Combined with optical clearing, here we demonstrate the preparation of semi-thick fixed brain slices for high-resolution fluorescent imaging.

Here we describe a rapid and simple method to image fluorescently labeled cells in semi-thick brain slices. By fixing, slicing, and optically clearing brain tissue we describe how standard epifluorescent or confocal imaging can be used to visualize individual cells and neuronal networks within intact nervous tissue.

Uma abordagem rápida para alta resolução de imagem de fluorescência em fatias grossas Semi-Cérebro

A fundamental goal to both basic and clinical neuroscience is to better understand the identities, molecular makeup, and patterns of connectivity that are ...

GABA-activated Single-channel and Tonic Currents in Rat Brain Slices

The GABAA channels are present in all neurons and are located both at synapses and outside of synapses where they generate phasic and tonic currents, respectively 4,5,6,7 The GABAA channel is a pentameric GABA-gated chloride channel. The channel subunits are grouped into 8 families (&alpha;1-6, &beta;1-3, &gamma;1-3, &delta;, &#949;, &theta;, &pi; and &rho;). Two alphas, two betas and one 3rd subunit form the functional channel 8. By combining studies of sub-type specific GABA-activated single-channel molecules with studies including all populations of GABAA channels in the neuron it becomes possible to understand the basic mechanism of neuronal inhibition and how it is modulated by pharmacological agents.
We use the patch-clamp technique 9,10 to study the functional properties of the GABAA channels in alive neurons in hippocampal brain slices and record the single-channel and whole-cell currents. We further examine how the channels are affected by different GABA concentrations, other drugs and intra and extracellular factors. For detailed theoretical and practical description of the patch-clamp method please see The Single-Channel Recordings edited by B Sakman and E Neher 10.

We use the patch-clamp technique to measure GABA-activated single-channel currents (GABAA channels, GABAA receptors) and the synaptic and tonic currents they generate in neurons. Activation of the channels decreases neuronal excitability in health and disease 1,2,3,4.

GABA-activated Correntes canal único e Tonic em fatias de cérebro de rato

The GABAA channels are present in all neurons and are located both at synapses and outside of synapses where they generate phasic and tonic currents, ...

Methods for Study of Neuronal Morphogenesis: Ex vivo RNAi Electroporation in Embryonic Murine Cerebral Cortex

The cerebral cortex directs higher cognitive functions. This six layered structure is generated in an inside-first, outside-last manner, in which the first born neurons remain closer to the ventricle while the last born neurons migrate past the first born neurons towards the surface of the brain1. In addition to neuronal migration2, a key process for normal cortical function is the regulation of neuronal morphogenesis3. While neuronal morphogenesis can be studied in vitro in primary cultures, there is much to be learned from how these processes are regulated in tissue environments.
We describe techniques to analyze neuronal migration and/or morphogenesis in organotypic slices of the cerebral cortex4,6. A pSilencer modified vector is used which contains both a U6 promoter that drives the double stranded hairpin RNA and a separate expression cassette that encodes GFP protein driven by a CMV promoter7-9. Our approach allows for the rapid assessment of defects in neurite outgrowth upon specific knockdown of candidate genes and has been successfully used in a screen for regulators of neurite outgrowth8. Because only a subset of cells will express the RNAi constructs, the organotypic slices allow for a mosaic analysis of the potential phenotypes. Moreover, because this analysis is done in a near approximation of the in vivo environment, it provides a low cost and rapid alternative to the generation of transgenic or knockout animals for genes of unknown cortical function. Finally, in comparison with in vivo electroporation technology, the success of ex vivo electroporation experiments is not dependant upon proficient surgery skill development and can be performed with a shorter training time and skill.

Methods for Study of Neuronal Morphogenesis: Ex vivo RNAi Electroporation in Embryonic Murine Cerebral Cortex

To conduct a rapid assessment of the function of genes in the development of cerebral cortex, we describe methods involving the ex vivo electroporation of plasmids co-expressing inhibitory RNA (RNAi) and GFP in murine embryonic cortex. This protocol is amenable to the study of various aspects of neurodevelopment such as neurogenesis, neuronal migration and neuronal morphogenesis including dendrite and axon outgrowth.

Métodos de Estudo da morfogênese neuronal:<em&gt; Ex vivo</em&gt; Eletroporação RNAi no Cortex Cerebral Murina embrionárias

The cerebral cortex directs higher cognitive functions. This six layered structure is generated in an inside-first, outside-last manner, in which the ...

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Neuroimagem Funcional Usando rompimento da barreira hemato-encefálica ultra-sônico e Manganês-RM

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Brain Slice Biotinylation: An Ex Vivo Approach to Measure Region-specific Plasma Membrane Protein Trafficking in Adult Neurons

Regulated endocytic trafficking is the central mechanism facilitating a variety of neuromodulatory events, by dynamically controlling receptor, ion channel, and transporter cell surface presentation on a minutes time scale.&#160;There is a broad diversity of mechanisms that control endocytic trafficking of individual proteins. Studies investigating the molecular underpinnings of trafficking have primarily relied upon surface biotinylation to quantitatively measure changes in membrane protein surface expression in response to exogenous stimuli and gene manipulation.&#160;However, this approach has been mainly limited to cultured cells, which may not faithfully reflect the physiologically relevant mechanisms at play in adult neurons.&#160;Moreover, cultured cell approaches may underestimate region-specific differences in trafficking mechanisms.&#160;Here, we describe an approach that extends cell surface biotinylation to the acute brain slice preparation.&#160;We demonstrate that this method provides a high-fidelity approach to measure rapid changes in membrane protein surface levels in adult neurons.&#160;This approach is likely to have broad utility in the field of neuronal endocytic trafficking.

Brain Slice Biotinylation: An Ex Vivo Approach to Measure Region-specific Plasma Membrane Protein Trafficking in Adult Neurons

Neuronal membrane trafficking dynamically controls plasma membrane protein availability and significantly impacts neurotransmission.&#160;To date, it has been challenging to measure neuronal endocytic trafficking in adult neurons.&#160;Here, we describe a highly effective, quantitative method to measure rapid changes in surface protein expression ex vivo in acute brain slices.

Cérebro Fatia Biotinilação: Uma<em&gt; Ex Vivo</em&gt; Abordagem medir Região específicas do tráfego de proteínas de membrana plasmática em adultos Neurônios

Regulated endocytic trafficking is the central mechanism facilitating a variety of neuromodulatory events, by dynamically controlling receptor, ion ...

Mouse Hindbrain Ex Vivo Culture to Study Facial Branchiomotor Neuron Migration

Embryonic neurons are born in the ventricular zone of the brain, but subsequently migrate to new destinations to reach appropriate targets. Deciphering the molecular signals that cooperatively guide neuronal migration in the embryonic brain is therefore important to understand how the complex neural networks form which later support postnatal life. Facial branchiomotor (FBM) neurons in the mouse embryo hindbrain migrate from rhombomere (r) 4 caudally to form the paired facial nuclei in the r6-derived region of the hindbrain. Here we provide a detailed protocol for wholemount ex vivo culture of mouse embryo hindbrains suitable to investigate the signaling pathways that regulate FBM migration. In this method, hindbrains of E11.5 mouse embryos are dissected and cultured in an open book preparation on cell culture inserts for 24 hr. During this time, FBM neurons migrate caudally towards r6 and can be exposed to function-blocking antibodies and small molecules in the culture media or heparin beads loaded with recombinant proteins to examine roles for signaling pathways implicated in guiding neuronal migration.

Mouse Hindbrain Ex Vivo Culture to Study Facial Branchiomotor Neuron Migration

Embryonic neurons are born in the ventricular zone of the neural tube, but migrate to reach appropriate targets. Facial branchiomotor (FBM) neurons are a useful model to study neuronal migration. This protocol describes the wholemount ex vivo culture of mouse embryo hindbrains to investigate mechanisms that regulate FBM migration.

Rato rombencéfalo<em&gt; Ex Vivo</em&gt; Cultura para estudar Facial Migração Branchiomotor Neuron

Embryonic neurons are born in the ventricular zone of the brain, but subsequently migrate to new destinations to reach appropriate targets. Deciphering ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

We present a protocol utilizing two-photon excitation time-lapse microscopy to simultaneously visualize the dynamics of axon and myelin injuries in real time. This proposed protocol permits studies of both intrinsic and extrinsic factors which can influence central myelinated axon fate after injury and contribute to permanent clinical disability.

Um<em&gt; Ex Vivo</em&gt; Induzida por laser Lesão Medular modelo para avaliar mecanismos de axonal Degeneration em tempo real

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices

Optogenetic approaches are now widely used to study the function of neural populations and circuits by combining targeted expression of light-activated proteins and subsequent manipulation of neural activity by light. Channelrhodopsins (ChRs) are light-gated cation-channels and when fused to a fluorescent protein their expression allows for visualization and concurrent activation of specific cell types and their axonal projections in defined areas of the brain. Via stereotactic injection of viral vectors, ChR fusion proteins can be constitutively or conditionally expressed in specific cells of a defined brain region, and their axonal projections can subsequently be studied anatomically and functionally via ex vivo optogenetic activation in brain slices. This is of particular importance when aiming to understand synaptic properties of connections that could not be addressed with conventional electrical stimulation approaches, or in identifying novel afferent and efferent connectivity that was previously poorly understood. Here, a few examples illustrate how this technique can be applied to investigate these questions to elucidating fear-related circuits in the amygdala. The amygdala is a key region for acquisition and expression of fear, and storage of fear and emotional memories. Many lines of evidence suggest that the medial prefrontal cortex (mPFC) participates in different aspects of fear acquisition and extinction, but its precise connectivity with the amygdala is just starting to be understood. First, it is shown how ex vivo optogenetic activation can be used to study aspects of synaptic communication between mPFC afferents and target cells in the basolateral amygdala (BLA). Furthermore, it is illustrated how this ex vivo optogenetic approach can be applied to assess novel connectivity patterns using a group of GABAergic neurons in the amygdala, the paracapsular intercalated cell cluster (mpITC), as an example.

Ex Vivo Optogenetic Dissection of Fear Circuits in Brain Slices

Optogenetic approaches are widely used to manipulate neural activity and assess the consequences for brain function. Here, a technique is outlined that&#160;upon in vivo expression of the optical activator Channelrhodopsin, allows for ex vivo analysis of synaptic properties of specific long range and local neural connections in fear-related circuits.

Ex Vivo optogenética Dissection de Circuitos medo no cérebro Slices

Optogenetic approaches are now widely used to study the function of neural populations and circuits by combining targeted expression of light-activated ...

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new method of Ca2+-imaging using the bioluminescent reporter GFP-aequorin (GA) has been developed. This new technique relies on the fusion of the GFP and aequorin genes, producing a molecule capable of binding calcium and&#160;&#8212; with the addition of its cofactor coelenterazine &#8212; emitting bright light that can be monitored through a photon collector. Transgenic lines carrying the GFP-aequorin gene have been generated for both mice and Drosophila. In Drosophila, the GFP-aequorin gene has been placed under the control of the GAL4/UAS binary expression system allowing for targeted expression and imaging within the brain. This method has subsequently been shown to be capable of detecting both inward Ca2+-transients and Ca2+-released from inner stores. Most importantly it allows for a greater duration in continuous recording, imaging at greater depths within the brain, and recording at high temporal resolutions (up to 8.3 msec). Here we present the basic method for using bioluminescent imaging to record and analyze Ca2+-activity within the mushroom bodies, a structure central to learning and memory in the fly brain.

In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin

Here we present a novel Ca2+-imaging approach using a bioluminescent reporter. This approach uses a fused construct GFP-aequorin which binds to Ca2+ and emits light, eliminating the need for light excitation. Significantly this method permits long continuous imaging, access to deep brain structures and high temporal resolution.

In Vivo funcional do cérebro Imagiologia Abordagem Baseada em cálcio Bioluminescent Indicador GFP-aequorina

Functional in vivo imaging has become a powerful approach to study the function and physiology of brain cells and structures of interest. Recently a new ...

Uma abordagem alternativa para estudar eventos primários na neurodegeneração usando fatias de cérebro de rato Ex Vivo

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