Trabalho apoiado pelo NIH conceder AG027297, um prêmio do Cabo de Kentucky e Confiança Spinal Injury Research cabeça, e um presente da Fundação Kleberg.

<ol>
	<li>Norris, C. M., Halpain, S., Foster, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alterations+in+the+balance+of+protein+kinase/phosphatase+activities+parallel+reduced+synaptic+strength+during+aging.">Alterations in the balance of protein kinase/phosphatase activities parallel reduced synaptic strength during aging.</a> J Neurophysiol. 80, 1567-1570 (1998).</li><li>Norris, C. M., Korol, D. L., Foster, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+susceptibility+to+induction+of+long-term+depression+and+long-term+potentiation+reversal+during+aging.">Increased susceptibility to induction of long-term depression and long-term potentiation reversal during aging.</a> J Neurosci. 16, 5382-5392 (1996).</li><li>Norris, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+'zipper'+slice+studies+reveal+a+necessary+role+for+calcineurin+in+the+increased+activity+of+L-type+Ca(2+)+channels+with+aging.">Hippocampal 'zipper' slice studies reveal a necessary role for calcineurin in the increased activity of L-type Ca(2+) channels with aging.</a> Neurobiol Aging. 31, 328-338 (2010).</li><li>Burke, S. N., Barnes, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Senescent+synapses+and+hippocampal+circuit+dynamics.">Senescent synapses and hippocampal circuit dynamics.</a> Trends Neurosci. 33, 153-161 (2010).</li><li>Foster, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+homeostasis+and+modulation+of+synaptic+plasticity+in+the+aged+brain.">Calcium homeostasis and modulation of synaptic plasticity in the aged brain.</a> Aging Cell. 6, 319-325 (2007).</li><li>Foster, T. C., Norris, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-associated+changes+in+Ca(2+)-dependent+processes:+relation+to+hippocampal+synaptic+plasticity.">Age-associated changes in Ca(2+)-dependent processes: relation to hippocampal synaptic plasticity.</a> Hippocampus. 7, 602-612 (1997).</li><li>Thibault, O., Gant, J. C., Landfield, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expansion+of+the+calcium+hypothesis+of+brain+aging+and+Alzheimer's+disease:+minding+the+store.">Expansion of the calcium hypothesis of brain aging and Alzheimer's disease: minding the store.</a> Aging Cell. 6, 307-317 (2007).</li><li>Demuro, A., Parker, I., Stutzmann, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+signaling+and+amyloid+toxicity+in+Alzheimer+disease.">Calcium signaling and amyloid toxicity in Alzheimer disease.</a> J Biol Chem. 285, 12463-12468 (2010).</li><li>Green, K. N., LaFerla, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linking+calcium+to+Abeta+and+Alzheimer's+disease.">Linking calcium to Abeta and Alzheimer's disease.</a> Neuron. 59, 190-194 (2008).</li><li>Kumar, A., Thinschmidt, J. S., Foster, T. C., King, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging+effects+on+the+limits+and+stability+of+long-term+synaptic+potentiation+and+depression+in+rat+hippocampal+area+CA1.">Aging effects on the limits and stability of long-term synaptic potentiation and depression in rat hippocampal area CA1.</a> J Neurophysiol. 98, 594-601 (2007).</li><li>Norris, C. M., Halpain, S., Foster, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversal+of+age-related+alterations+in+synaptic+plasticity+by+blockade+of+L-type+Ca2++channels.">Reversal of age-related alterations in synaptic plasticity by blockade of L-type Ca2+ channels.</a> J Neurosci. 18, 3171-3179 (1998).</li><li>Norris, C. M., Scheff, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+of+afferent+function+and+synaptic+strength+in+hippocampal+CA1+following+traumatic+brain+injury.">Recovery of afferent function and synaptic strength in hippocampal CA1 following traumatic brain injury.</a> J Neurotrauma. 26, 2269-2278 (2009).</li><li>Sama, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interleukin-1beta-dependent+signaling+between+astrocytes+and+neurons+depends+critically+on+astrocytic+calcineurin/NFAT+activity.">Interleukin-1beta-dependent signaling between astrocytes and neurons depends critically on astrocytic calcineurin/NFAT activity.</a> J Biol Chem. 283, 21953-21964 (2008).</li><li>Ye, H., Jalini, S., Mylvaganam, S., Carlen, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+large-conductance+Ca(2+)-activated+K(+)+channels+depresses+basal+synaptic+transmission+in+the+hippocampal+CA1+area+in+APP+(swe/ind)+TgCRND8+mice.">Activation of large-conductance Ca(2+)-activated K(+) channels depresses basal synaptic transmission in the hippocampal CA1 area in APP (swe/ind) TgCRND8 mice.</a> Neurobiol Aging. 31, 591-604 (2010).</li><li>Bear, M. F., Malenka, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+plasticity:+LTP+and+LTD.">Synaptic plasticity: LTP and LTD.</a> Curr Opin Neurobiol. 4, 389-399 (1994).</li><li>Foster, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+hippocampal+synaptic+plasticity+in+age-related+memory+decline.">Involvement of hippocampal synaptic plasticity in age-related memory decline.</a> Brain Res Brain Res Rev. 30, 236-249 (1999).</li><li>Foster, T. C., Kumar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Susceptibility+to+induction+of+long-term+depression+is+associated+with+impaired+memory+in+aged+Fischer+344+rats.">Susceptibility to induction of long-term depression is associated with impaired memory in aged Fischer 344 rats.</a> Neurobiol Learn Mem. 87, 522-535 (2007).</li><li>Hsu, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alterations+in+the+balance+of+protein+kinase+and+phosphatase+activities+and+age-related+impairments+of+synaptic+transmission+and+long-term+potentiation.">Alterations in the balance of protein kinase and phosphatase activities and age-related impairments of synaptic transmission and long-term potentiation.</a> Hippocampus. 12, 787-802 (2002).</li><li>Vouimba, R. M., Foy, M. R., Foy, J. G., Thompson, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=17beta-estradiol+suppresses+expression+of+long-term+depression+in+aged+rats.">17beta-estradiol suppresses expression of long-term depression in aged rats.</a> Brain Res Bull. 53, 783-787 (2000).</li><li>Abdul, H. M., Furman, J. L., Sama, M. A., Mathis, D. M., Norris, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NFATs+and+Alzheimer's+Disease.">NFATs and Alzheimer's Disease.</a> Mol Cell Pharmacol. 2, 7-14 (2010).</li><li>Abdul, H. M. <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+in+Alzheimer's+disease+is+associated+with+selective+changes+in+calcineurin/NFAT+signaling.">Cognitive decline in Alzheimer's disease is associated with selective changes in calcineurin/NFAT signaling.</a> J Neurosci. 29, 12957-12969 (2009).</li><li>Anantharaman, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta-amyloid+mediated+nitration+of+manganese+superoxide+dismutase:+implication+for+oxidative+stress+in+a+APPNLH/NLH+X+PS-1P264L/P264L+double+knock-in+mouse+model+of+Alzheimer's+disease.">Beta-amyloid mediated nitration of manganese superoxide dismutase: implication for oxidative stress in a APPNLH/NLH X PS-1P264L/P264L double knock-in mouse model of Alzheimer's disease.</a> Am J Pathol. 168, 1608-1618 (2006).</li><li>Gengler, S., Hamilton, A., Holscher, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+plasticity+in+the+hippocampus+of+a+APP/PS1+mouse+model+of+Alzheimer's+disease+is+impaired+in+old+but+not+young+mice.">Synaptic plasticity in the hippocampus of a APP/PS1 mouse model of Alzheimer's disease is impaired in old but not young mice.</a> PLoS One. 5, e9764-e9764 (2010).</li><li>Stringer, J. L., Lothman, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+effects+of+extracellular+calcium+concentrations+on+hippocampal+pyramidal+cell+responses.">In vitro effects of extracellular calcium concentrations on hippocampal pyramidal cell responses.</a> Exp Neurol. 101, 132-146 (1988).</li><li>Landfield, P. W., Pitler, T. A., Applegate, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+high+Mg2+-to-Ca2++ratios+on+frequency+potentiation+in+hippocampal+slices+of+young+and+aged+rats.">The effects of high Mg2+-to-Ca2+ ratios on frequency potentiation in hippocampal slices of young and aged rats.</a> J Neurophysiol. 56, 797-811 (1986).</li><li>Ames, A., Sakanoue, M., Endo, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NA,+K,+CA,+MG,+AND+C1+CONCENTRATIONS+IN+CHOROID+PLEXUS+FLUID+AND+CISTERNAL+FLUID+COMPARED+WITH+PLASMA+ULTRAFILTRATE.">NA, K, CA, MG, AND C1 CONCENTRATIONS IN CHOROID PLEXUS FLUID AND CISTERNAL FLUID COMPARED WITH PLASMA ULTRAFILTRATE.</a> J Neurophysiol. 27, 672-681 (1964).</li><li>Gant, J. C., Sama, M. M., Landfield, P. W., Thibault, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+and+simultaneous+emergence+of+multiple+hippocampal+biomarkers+of+aging+is+mediated+by+Ca2+-induced+Ca2++release.">Early and simultaneous emergence of multiple hippocampal biomarkers of aging is mediated by Ca2+-induced Ca2+ release.</a> J Neurosci. 26, 3482-3490 (2006).</li><li>Thibault, O., Hadley, R., Landfield, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elevated+postsynaptic+[Ca2+]i+and+L-type+calcium+channel+activity+in+aged+hippocampal+neurons:+relationship+to+impaired+synaptic+plasticity.">Elevated postsynaptic [Ca2+]i and L-type calcium channel activity in aged hippocampal neurons: relationship to impaired synaptic plasticity.</a> J Neurosci. 21, 9744-9756 (2001).</li><li>Thibault, O., Landfield, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increase+in+single+L-type+calcium+channels+in+hippocampal+neurons+during+aging.">Increase in single L-type calcium channels in hippocampal neurons during aging.</a> Science. 272, 1017-1020 (1996).</li><li>Stutzmann, G. E., Caccamo, A., LaFerla, F. M., Parker, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dysregulated+IP3+signaling+in+cortical+neurons+of+knock-in+mice+expressing+an+Alzheimer's-linked+mutation+in+presenilin1+results+in+exaggerated+Ca2++signals+and+altered+membrane+excitability.">Dysregulated IP3 signaling in cortical neurons of knock-in mice expressing an Alzheimer's-linked mutation in presenilin1 results in exaggerated Ca2+ signals and altered membrane excitability.</a> J Neurosci. 24, 508-513 (2004).</li><li>Stutzmann, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+ryanodine+receptor+recruitment+contributes+to+Ca2++disruptions+in+young,+adult,+and+aged+Alzheimer's+disease+mice.">Enhanced ryanodine receptor recruitment contributes to Ca2+ disruptions in young, adult, and aged Alzheimer's disease mice.</a> J Neurosci. 26, 5180-5189 (2006).</li><li>Lee, H. K., Min, S. S., Gallagher, M., Kirkwood, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMDA+receptor-independent+long-term+depression+correlates+with+successful+aging+in+rats.">NMDA receptor-independent long-term depression correlates with successful aging in rats.</a> Nat Neurosci. 8, 1657-1659 (2005).</li><li>McNaughton, B. L., Douglas, R. M., Goddard, G. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+enhancement+in+fascia+dentata:+cooperativity+among+coactive+afferents.">Synaptic enhancement in fascia dentata: cooperativity among coactive afferents.</a> Brain Res. 157, 277-293 (1978).</li></ol>

A produção deste vídeo-artigo foi patrocinado pela Leica Microsystems.

Os passos descritos neste protocolo vai ajudar a garantir que dissecações do cérebro são realizadas pelo menos tão rapidamente e eficientemente em idosos, como em ratos adultos jovens. Nós também fornecemos detalhes suficientes para o iniciante a criarem a sua própria fatia estudos sobre LTP e LTD. Se uma maior exploração do envelhecimento e as mudanças AD em função sináptica e plasticidade é um dos seus objetivos, existem pelo menos duas outras questões metodológicas, aludido acima, que merecem análise mais aprofundada. Primeiro, vários laboratórios têm mostrado que o Ca 2 +: Mg2 + taxa em gravação ACSF pode ter um efeito marcante sobre a plasticidade sináptica indução em fatias do hipocampo 2,10,24,25. CSF em mamíferos, o Ca 2 +: Mg2 + taxa é de aproximadamente um (por exemplo, ver 26). No entanto, ACSF Ca 2 +: Mg2 + taxas mais próximas a 2 são comumente usados ​​em estudos fatia de função sináptica e plasticidade. Nos primeiros estudos, esta prática foi provavelmente adaptado para otimizar a indução da LTP e, posteriormente tornou-se rotina para todos os estudos de plasticidade. No entanto, esta prática pode ser problemático em estudos de envelhecimento e AD por causa das diferenças bem caracterizadas em Ca 2 neuronal regulação +. Especificamente, Ca 2 + fluxo e / ou Ca 2 + induzida por Ca 2 +-lançamento é elevada em ratos idosos e / ou camundongos modelo AD durante a ativação neuronal 3,27-31. Indução de LTD é particularmente sensível a mudanças sutis na ACSF Ca 2 + níveis. Nosso protocolo, que usa 2mM Ca 2 + e 2 mM Mg2 +, geralmente resulta em LTD para idosos, mas não jovens animais adultos 2, enquanto que estudos usando um Ca 2 +: Mg2 + relação próxima dos dois, observaram LTD robusta em adultos no ausência de uma diferença de idade 2,10 ou em conjunto com LTD reduzidos em ratos de 32 anos. Estas observações evidenciam a necessidade de considerar cuidadosamente ACSF Ca 2 + e Mg 2 + quando se comparam os níveis de Ca 2 + dependentes de plasticidade em animais adultos idosos e jovens. A segunda questão metodológica diz respeito à forte dependência da LTP na despolarização pós-sináptica 33 e possíveis envelhecimento / genótipo diferenças na força sináptica. Em um experimento de LTP típica, linha de base e LTP a intensidade do estímulo é geralmente ajustada para produzir uma meia máxima (ou três quartos máxima) amplitude EPSP. O problema potencial é que os ratos idosos e APP/PS1 ratos geralmente mostram redução da força sináptica em relação aos seus colegas mais jovens tipo e / ou selvagens, o que significa que os valores EPSP base também será menor em ratos idosos e APP/PS1 camundongos. EPSPs menores podem traduzir para menos despolarização durante a estimulação LTP, resultando em uma menor probabilidade de induzir LTP 33. Devido a isso confundir potencial, é difícil determinar se esses animais apresentam um déficit de transmissão, o déficit de plasticidade, ou ambos. Ou seja, mecanismos de indução de LTP em idade e / ou APP/PS1 ratos podem ser funcionalmente intacto (sem déficit de plasticidade), mas insuficientemente estimuladas (déficit throughput) nessas condições. Esta distinção é fundamental, como mecanismos de transferência e os mecanismos de plasticidade podem responder de forma muito diferente a um tratamento farmacológico específico. Tentamos minimizar o impacto da vazão reduzida na indução de LTP através da normalização da amplitude EPSP ao mesmo nível (por exemplo, 1 mV) em todas as fatias anterior à estimulação LTP. Outras estratégias podem ser eficazes, bem como (por exemplo, utilização de tensão ou pinça de corrente para igualar o potencial de membrana entre os grupos durante a estimulação LTP), e devem ser considerados quando se investiga LTP nestes modelos animais.

<table border="1"><tbody><tr><td> Nome do reagente </td><td> Companhia </td><td> Número de catálogo </td></tr><tr><td> NaCl </td><td> Pescador </td><td> BP358-1 </td></tr><tr><td> KCl </td><td> Pescador </td><td> BP366-500 </td></tr><tr><td> KH 2 PO 4 (monossódico) </td><td> Sigma </td><td> P5379-100G </td></tr><tr><td> MgSO 4 </td><td> Sigma </td><td> M2643-500G </td></tr><tr><td> CaCl 2 (di) </td><td> Sigma </td><td> C3306-250G </td></tr><tr><td> NaHCO 3 </td><td> Pescador </td><td> S233-500 </td></tr><tr><td> C 6 H 12 O 6 (dextrose) </td><td> Pescador </td><td> BP350-1 </td></tr></tbody></table> Reagentes tabela 1. Necessárias <table border="1"><tbody><tr><td> Nome do equipamento </td><td> Companhia </td><td> Número de catálogo </td><td> Comentários </td></tr><tr><td> Erlenmeyers </td><td> Pescador </td><td> FB-500-2000 FB-500-1000 </td><td></td></tr><tr><td> Aquarium Bubbler </td><td></td><td></td><td> Usado para oxigenar mídia. Disponíveis na maioria das lojas de animais </td></tr><tr><td> 50 copo de vidro mL </td><td> Pescador </td><td> 02-540g </td><td> Para storarge cérebro em ACSF </td></tr><tr><td> Parafilm </td><td> Pescador </td><td> 13-374-10 </td><td></td></tr><tr><td> Guilhotina de Pequenos Animais </td><td> Mundial Precision Instruments (WPI) </td><td> DCAP-M </td><td></td></tr><tr><td> Toalha de papel plano </td><td></td><td></td><td></td></tr><tr><td> # Feather lâmina cirúrgica 11 </td><td> Pescador </td><td> 08-916-5B </td><td></td></tr><tr><td> Beebee osso tesoura </td><td> Multa Ferramentas da Ciência (FST) </td><td> 16044-10 </td><td></td></tr><tr><td> Lempert Rongeurs </td><td> Roboz </td><td> RS-8321 </td><td> Use para ratos </td></tr><tr><td> Friedman-Pearson Rongeurs </td><td> FST </td><td> 16020-14 </td><td> Use para camundongos ou ratos </td></tr><tr><td> Ferramenta hipocampo </td><td> FST </td><td> 10099-15 </td><td></td></tr><tr><td> Colher </td><td></td><td></td><td> Uma colher de chá vai fazer plástica </td></tr><tr><td> Espátula </td><td> Pescador </td><td> 21-401-25A </td><td> Espátula </td></tr><tr><td> Cirúrgica da íris tesoura </td><td> FST </td><td> 14058-09 </td><td></td></tr><tr><td> plástico pipetas de transferência </td><td> Pescador </td><td> 13-711-43 </td><td></td></tr><tr><td> 110 milímetros de papel de filtro Whatman </td><td> Pescador </td><td> 09-805E </td><td> Whatman cat. 1001-110 </td></tr><tr><td> Placa de Petri de vidro </td><td> Pescador </td><td></td><td></td></tr><tr><td> Leica VT1000P manual vibratório micrótomo </td><td> Vibratome </td><td></td><td></td></tr><tr><td> Lâmina de 0,1 milímetros FA-10 Feather S </td><td> Ted Pella </td><td> 121-9 </td><td> Lâmina de 0,1 milímetros FA-10 Feather S </td></tr><tr><td> Vidro borosilicato Pipetar Pasteur (com bulbo de borracha) </td><td> Pescador </td><td> 13-678-20A </td><td> Para a transferência de fatias: Dica está quebrado e calor polida para maior abertura </td></tr><tr><td> 35 prato de Cultura milímetros Polysterine </td><td> Corning </td><td> 430588 </td><td> Utilizado para a recolha de cortes após a dissecção </td></tr></tbody></table> Tabela 2. Ferramentas e materiais para dissecção <table border="1"><tbody><tr><td> Equipamentos / materiais </td><td> Companhia </td><td> Comentários (opcional) </td></tr><tr><td> Segurando câmara </td><td> Custom Built </td><td></td></tr><tr><td> P-97 Horizontal Pipetar Puller </td><td> Sutter Instrument Co. </td><td></td></tr><tr><td> Mesa de isolamento de vibração </td><td> Técnico Manufacturing Corporation (TMC) </td><td></td></tr><tr><td> Gaiola de Faraday </td><td> Personalizado construído </td><td></td></tr><tr><td> Pyrex Garrafa Aspirador com Sidearm Inferior (Produto # 1220-1E) </td><td> Corning </td><td></td></tr><tr><td> Gravidade contolled set IV com regulador (Produto # 2C8891) </td><td> Baxter </td><td></td></tr><tr><td> Linha de Aspiração Central </td><td></td><td> Disponível na maioria dos laboratórios modernos </td></tr><tr><td> 95% O 2 / 5% CO 2 Gas Mix </td><td> Escocêst-Gross Co. </td><td></td></tr><tr><td> TygonTM tubulação Lab Para O 2 / CO 2 de entrega </td><td> Fisher Scientific </td><td> Não-tóxica, não-oxidantes, vem em uma variedade de tamanhos. </td></tr><tr><td> Microscópio Eclipse E600FN </td><td> Nikon </td><td> com os objetivos de 10x e 40x, perto do filtro infared e GFP, DS-Red2 filtros </td></tr><tr><td> Legal snap ES Câmera Digital </td><td> Fotométricos </td><td> Legal snap ES Câmera Digital </td></tr><tr><td> X-Cite Iluminador Fluorescente </td><td> EXFO </td><td> X-Cite Iluminador Fluorescente </td></tr><tr><td> Plataforma microscópio </td><td> Siskiyou </td><td> Personalizado montado </td></tr><tr><td> RC-22 submersíveis de gravação da câmara (Produto # 64-0228) </td><td> Warner Instruments (WI) </td><td> Requer P-1 adaptador de plataforma e palco (Produto # 64-0277 De Warner) </td></tr><tr><td> TC2BIP controlador de temperatura 2/3Ch </td><td> Microcontrols celular </td><td> TC2BIP controlador de temperatura 2/3Ch </td></tr><tr><td> 4 Axis manipulador Miniature manual </td><td> Siskiyou </td><td></td></tr><tr><td> Fio de platina Iridium (0,002 in) (Item # PTT0203) </td><td> WPI </td><td></td></tr><tr><td> A365 Isolator Stimulus </td><td> WPI </td><td> A365 Isolator Stimulus </td></tr><tr><td> Multiclamp Amplificador 700B </td><td> Axon Instruments </td><td></td></tr><tr><td> Digidata 1322A conversor A / D </td><td> Axon Instruments </td><td></td></tr><tr><td> Software PClamp </td><td> Axon Instruments </td><td></td></tr><tr><td> Computador pessoal (Pentium 4) </td><td> Dell </td><td></td></tr></tbody></table> Tabela 3. Eletrofisiologia equipamentos e materiais

preparation of acute hippocampal slices from rats and transgenic mice for the study of synaptic alterations during aging and amyloid pathology

O roedor preparação fatia do hipocampo é talvez a ferramenta mais amplamente utilizado para investigar função sináptica mamíferos e plasticidade. O hipocampo pode ser extraído de forma rápida e facilmente de ratos e camundongos e fatias de permanecer viável por horas em oxigenado líquido cefalorraquidiano artificial. Além disso, técnicas básicas electrophysisologic são facilmente aplicadas à investigação da função sináptica em fatias do hipocampo e forneceram algumas das melhores biomarcadores para deficiências cognitivas. A fatia do hipocampo é especialmente popular para o estudo de mecanismos de plasticidade sináptica envolvida na aprendizagem e memória. Mudanças na indução de potenciação de longa duração e depressão (LTP e LTD) da eficácia sináptica em fatias do hipocampo (ou falta dele) são freqüentemente usados ​​para descrever o fenótipo neurológico de animais com deficiência cognitiva e / ou para avaliar o mecanismo de ação da compostos nootropic. Este artigo descreve os procedimentos que usamos para preparar fatias do hipocampo de ratos e camundongos transgênicos para o estudo de alterações sinápticas do cérebro associadas com o envelhecimento ea doença de Alzheimer (AD) 1-3. Uso de ratos e camundongos com idade modelo AD pode apresentar um conjunto único de desafios para os pesquisadores acostumados a usar ratos mais jovens e / ou ratos em suas pesquisas. Ratos idosos têm crânios mais espessa e mais resistente do tecido conjuntivo de ratos mais jovens e camundongos, o que pode atrasar extração de cérebro e / ou dissecção e, conseqüentemente, negar ou exagerar verdadeira idade diferenças na função sináptica e plasticidade. Envelhecimento e patologia amilóide também pode agravar a lesão do hipocampo sustentada durante o processo de dissecação, novamente complicando qualquer inferências a partir da avaliação fisiológica. Aqui, discutimos as medidas tomadas durante o processo de dissecção para minimizar esses problemas. Exemplos de respostas sinápticas adquiridos em &quot;saudável&quot; e &quot;insalubre&quot; fatias de ratos e camundongos são fornecidos, bem como representante experimentos plasticidade sináptica. O possível impacto de outros fatores metodológicos sobre a função sináptica nestes modelos animais (por exemplo, componentes de gravação solução, parâmetros de estimulação) também são discutidos. Embora o foco deste artigo é sobre o uso de ratos idosos e camundongos transgênicos, os novatos para cortar fisiologia deve encontrar detalhes suficientes aqui para começar a fazer seus próprios estudos, usando uma variedade de modelos de roedores.

Watch this Scientific Journal Video about Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology at JoVE.com

Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology

Este artigo descreve procedimentos para preparar fatias do hipocampo de ratos e camundongos transgênicos para o estudo de alterações sinápticas do cérebro associadas ao envelhecimento e relacionadas com a idade as doenças neurodegenerativas, como doença de Alzheimer.

Preparação de fatias do hipocampo aguda de ratos e camundongos transgênicos para o Estudo das Alterações Synaptic durante o envelhecimento e amilóide Patologia

The rodent hippocampal slice preparation is perhaps the most broadly used tool for investigating mammalian synaptic function and plasticity. The ...

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Neuroscience

93.7K visualizações.  University of Kentucky College of Public Health. Este artigo descreve procedimentos para preparar fatias do hipocampo de ratos e camundongos transgênicos para o estudo de alterações sinápticas do cérebro associadas ao envelhecimento e relacionadas com a idade as doenças neurodegenerativas, como doença de Alzheimer.

Vídeo: Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology

Preparation of Oligomeric &beta;-amyloid1-42 and Induction of Synaptic Plasticity Impairment on Hippocampal Slices

Impairment of synaptic connections is likely to underlie the subtle amnesic changes occurring at the early stages of Alzheimer s Disease (AD). &beta;-amyloid (A&beta;), a peptide produced in high amounts in AD, is known to reduce Long-Term Potentiation (LTP), a cellular correlate of learning and memory. Indeed, LTP impairment caused by A&beta; is a useful experimental paradigm for studying synaptic dysfunctions in AD models and for screening drugs capable of mitigating or reverting such synaptic impairments. Studies have shown that A&beta; produces the LTP disruption preferentially via its oligomeric form. Here we provide a detailed protocol for impairing LTP by perfusion of oligomerized synthetic A&beta;1-42 peptide onto acute hippocampal slices. In this video, we outline a step-by-step procedure for the preparation of oligomeric A&beta;1-42. Then, we follow an individual experiment in which LTP is reduced in hippocampal slices exposed to oligomerized A&beta;1-42 compared to slices in a control experiment where no A&beta;1-42 exposure had occurred.

Preparation of Oligomeric &amp;#946;-amyloid1-42 and Induction of Synaptic Plasticity Impairment on Hippocampal Slices

One feature of Alzheimer's Disease is the elevation of A&beta;1-42 peptide. Here we provide a protocol for preparing synthetic A&beta;1-42 oligomers, which impairs hippocampal Long-Term Potentiation, a cellular correlate of memory. This procedure is useful for investigating mechanisms of A&beta;-induced pathology and drug screening.

Preparação de Oligoméricas β-amilóide 1-42 Indução e de Impairment plasticidade sináptica em fatias do hipocampo

Impairment of synaptic connections is likely to underlie the subtle amnesic changes occurring at the early stages of Alzheimer s Disease (AD). ...

Neurociência

Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of interest. This allows for examination of synaptic transmission under conditions where the extracellular and postsynaptic intracellular environments can be well controlled. A vibration-based technique without the use of proteases, known as vibrodissociation, is the most popular technique for mechanical isolation. A micropipette, with the tip fire-polished to the shape of a small ball, is placed into a brain slice made from a P1-P21 rodent. The micropipette is vibrated parallel to the slice surface and lowered through the slice thickness resulting in the liberation of isolated neurons. The isolated neurons are ready for study within a few minutes of vibrodissociation. This technique has advantages over the use of primary neuronal cultures, brain slices and enzymatically isolated neurons including: rapid production of viable, relatively mature neurons suitable for electrophysiological and imaging studies; superior control of the extracellular environment free from the influence of neighboring cells; suitability for well-controlled pharmacological experiments using rapid drug application and total cell superfusion; and improved space-clamp in whole-cell recordings relative to neurons in slice or cell culture preparations. This preparation can be used to examine synaptic physiology, pharmacology, modulation and plasticity. Real-time imaging of both pre- and postsynaptic elements in the living cells and boutons is also possible using vibrodissociated neurons. Characterization of the molecular constituents of pre- and postsynaptic elements can also be achieved with immunological and imaging-based approaches.

This report demonstrates a technique for mechanical isolation of individual viable neurons retaining attached presynaptic boutons. Vibrodissociated neurons have the advantages of rapid production, excellent pharmacological control and improved space-clamp without influence from neighboring cells. This method can be used for imaging of synaptic elements and patch-clamp recording.

Vibrodissociation de neurônios de fatias do cérebro de roedores para estudar a transmissão sináptica e Imagem Terminais pré-sináptica

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of ...

Preparation of Acute Subventricular Zone Slices for Calcium Imaging

The subventricular zone (SVZ) is one of the two neurogenic zones in the postnatal brain. The SVZ contains densely packed cells, including neural progenitor cells with astrocytic features (called SVZ astrocytes), neuroblasts, and intermediate progenitor cells. Neuroblasts born in the SVZ tangentially migrate a great distance to the olfactory bulb, where they differentiate into interneurons. Intercellular signaling through adhesion molecules and diffusible signals play important roles in controlling neurogenesis. Many of these signals trigger intercellular calcium activity that transmits information inside and between cells. Calcium activity is thus reflective of the activity of extracellular signals and is an optimal way to understand functional intercellular signaling among SVZ cells.
Calcium activity has been studied in many other regions and cell types, including mature astrocytes and neurons. However, the traditional method to load cells with calcium indicator dye (i.e. bath loading) was not efficient at loading all SVZ cell types. Indeed, the cellular density in the SVZ precludes dye diffusion inside the tissue. In addition, preparing sagittal slices will better preserve the three-dimensional arrangement of SVZ cells, particularly the stream of neuroblast migration on the rostral-caudal axis.
Here, we describe methods to prepare sagittal sections containing the SVZ, the loading of SVZ cells with calcium indicator dye, and the acquisition of calcium activity with time-lapse movies. We used Fluo-4 AM dye for loading SVZ astrocytes using pressure application inside the tissue. Calcium activity was recorded using a scanning confocal microscope allowing a precise resolution for distinguishing individual cells. Our approach is applicable to other neurogenic zones including the adult hippocampal subgranular zone and embryonic neurogenic zones. In addition, other types of dyes can be applied using the described method.

A method to load subventricular zone (SVZ) cells with calcium indicator dyes for recording calcium activity is described. The postnatal SVZ contains tightly packed cells including neural progenitor cells and neuroblasts. Rather than using bath loading we injected the dye by pressure inside the tissue allowing better dye diffusion.

Preparação de fatias agudas zona subventricular for Imaging Cálcio

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

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

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs through activation of their ion channels and neurotransmitter receptors, and process information in part through activity-dependent release of gliotransmitters. Furthermore, astrocytes constitute the main uptake system for glutamate, contribute to potassium spatial buffering, as well as to GABA clearance. These cells therefore constantly monitor synaptic activity, and are thereby sensitive indicators for alterations in synaptically-released glutamate, GABA and extracellular potassium levels. Additionally, alterations in astroglial uptake activity or buffering capacity can have severe effects on neuronal functions, and might be overlooked when characterizing physiopathological situations or knockout mice. Dual recording of neuronal and astroglial activities is therefore an important method to study alterations in synaptic strength associated to concomitant changes in astroglial uptake and buffering capacities. Here we describe how to prepare hippocampal slices, how to identify stratum radiatum astrocytes, and how to record simultaneously neuronal and astroglial electrophysiological responses. Furthermore, we describe how to isolate pharmacologically the synaptically-evoked astroglial currents.

The preparation of acute brain slices from isolated hippocampi, as well as the simultaneous electrophysiological recordings of astrocytes and neurons in stratum radiatum during stimulation of schaffer collaterals is described. The pharmacological isolation of astroglial potassium and glutamate transporter currents is demonstrated.

Dois registros eletrofisiológicos de sinapticamente evocadas Respostas astroglial e neuronal em fatias hipocampais agudas

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

Stereotaxic Infusion of Oligomeric Amyloid-beta into the Mouse Hippocampus

Alzheimer&#8217;s disease is a neurodegenerative disease affecting the aging population. A key neuropathological feature of the disease is the over-production of amyloid-beta and the deposition of amyloid-beta plaques in brain regions of the afflicted individuals. Throughout the years scientists have generated numerous Alzheimer&#8217;s disease mouse models that attempt to replicate the amyloid-beta pathology. Unfortunately, the mouse models only selectively mimic the disease features. Neuronal death, a prominent effect in the brains of Alzheimer&#8217;s disease patients, is noticeably lacking in these mice. Hence, we and others have employed a method of directly infusing soluble oligomeric species of amyloid-beta - forms of amyloid-beta that have been proven to be most toxic to neurons - stereotaxically into the brain. In this report we utilize male C57BL/6J mice to document this surgical technique of increasing amyloid-beta levels in a select brain region. The infusion target is the dentate gyrus of the hippocampus because this brain structure, along with the basal forebrain that is connected by the cholinergic circuit, represents one of the areas of degeneration in the disease. The results of elevating amyloid-beta in the dentate gyrus via stereotaxic infusion reveal increases in neuron loss in the dentate gyrus within 1 week, while there is a concomitant increase in cell death and cholinergic neuron loss in the vertical limb of the diagonal band of Broca of the basal forebrain. These effects are observed up to 2 weeks. Our data suggests that the current amyloid-beta infusion model provides an alternative mouse model to address region specific neuron death in a short-term basis. The advantage of this model is that amyloid-beta can be elevated in a spatial and temporal manner.

Here, we present a protocol for direct stereotaxic brain infusion of amyloid-beta. This methodology provides an alternative in vivo mouse model to address the short-term effects of amyloid-beta on brain neurons.

Infusão estereotáxica de oligomica beta-amilóide no ratinho Hippocampus

Alzheimer&#8217;s disease is a neurodegenerative disease affecting the aging population. A key neuropathological feature of the disease is the ...

Investigation of Synaptic Tagging/Capture and Cross-capture using Acute Hippocampal Slices from Rodents

Synaptic tagging and capture (STC) and cross-tagging are two important mechanisms at cellular level that explain how synapse-specificity and associativity is achieved in neurons within a specific time frame. These long-term plasticity-related processes are the leading candidate models to study the basis of memory formation and persistence at the cellular level. Both STC and cross-tagging involve two serial processes: (1) setting of the synaptic tag as triggered by a specific pattern of stimulation, and (2) synaptic capture, whereby the synaptic tag interacts with newly synthesized plasticity-related proteins (PRPs). Much of the understanding about the concepts of STC and cross-tagging arises from the studies done in CA1 region of the hippocampus and because of the technical complexity many of the laboratories are still unable to study these processes. Experimental conditions for the preparation of hippocampal slices and the recording of stable late-LTP/LTD are extremely important to study synaptic tagging/cross-tagging. This video article describes the experimental procedures to study long-term plasticity processes such as STC and cross-tagging in the CA1 pyramidal neurons using stable, long-term field-potential recordings from acute hippocampal slices of rats.

This video article describes experimental procedures to study long-term plasticity and its associative processes such as synaptic tagging, capture and cross-tagging in the CA1 pyramidal neurons using acute hippocampal slices from rodents.

Investigação de Synaptic Tagging / Captura e-captura Cruz usando aguda fatias do hipocampo de roedores

Synaptic tagging and capture (STC) and cross-tagging are two important mechanisms at cellular level that explain how synapse-specificity and associativity ...

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

This protocol is a practical guide to the N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. Numerous recent studies have validated the utility of this method for enhancing neuronal preservation and overall brain slice viability. The implementation of this technique by early adopters has facilitated detailed investigations into brain function using diverse experimental applications and spanning a wide range of animal ages, brain regions, and cell types. Steps are outlined for carrying out the protective recovery brain slice technique using an optimized NMDG artificial cerebrospinal fluid (aCSF) media formulation and enhanced procedure to reliably obtain healthy brain slices for patch clamp electrophysiology. With this updated approach, a substantial improvement is observed in the speed and reliability of gigaohm seal formation during targeted patch clamp recording experiments while maintaining excellent neuronal preservation, thereby facilitating challenging experimental applications. Representative results are provided from multi-neuron patch clamp recording experiments to assay synaptic connectivity in neocortical brain slices prepared from young adult transgenic mice and mature adult human neurosurgical specimens. Furthermore, the optimized NMDG protective recovery method of brain slicing is compatible with both juvenile and adult animals, thus resolving a limitation of the original methodology. In summary, a single media formulation and brain slicing procedure can be implemented across various species and ages to achieve excellent viability and tissue preservation.

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

This protocol demonstrates the implementation of an optimized N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. A single media formulation is used to reliably obtain healthy brain slices from animals of any age and for diverse experimental applications.

Preparação de fatias de cérebro aguda usando um otimizado N-metil-D-método de proteção de recuperação glucamine

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

Recording Synaptic Plasticity in Acute Hippocampal Slices Maintained in a Small-volume Recycling-, Perfusion-, and Submersion-type Chamber System

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful analysis of synaptic transmission modulation when performing field potential or intracellular recordings. This manuscript describes methodological aspects that might be helpful in improving experimental conditions for the maintenance of acute brain slices and for recording field excitatory postsynaptic potentials in a commercially available submersion chamber with an outflow-carbogenation unit. The outflow-carbogenation helps to stabilize the oxygen level in experiments that rely on the recycling of a small buffer reservoir to enhance the cost-efficiency of drug experiments. In addition, the manuscript presents representative experiments that examine the effects of different carbogenation modes and stimulation paradigms on the activity-dependent synaptic plasticity of synaptic transmission.

This protocol describes the stabilization of the oxygen level in a small volume of recycled buffer and methodological aspects of recording activity-dependent synaptic plasticity in submerged acute hippocampal slices.

Gravação de plasticidade sináptica em fatias Hippocampal agudas, mantidas em um pequeno volume reciclagem - perfusão- e sistema de câmara de submersão-tipo

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful ...

Single Synapse Indicators of Glutamate Release and Uptake in Acute Brain Slices from Normal and Huntington Mice

Synapses are highly compartmentalized functional units that operate independently on each other. In Huntington&#39;s disease (HD) and other neurodegenerative disorders, this independence might be compromised due to insufficient glutamate clearance and the resulting spill-in and spill-out effects. Altered astrocytic coverage of the presynaptic terminals and/or dendritic spines as well as a reduced size of glutamate transporter clusters at glutamate release sites have been implicated in the pathogenesis of diseases resulting in symptoms of dys-/hyperkinesia. However, the mechanisms leading to the dysfunction of glutamatergic synapses in HD are not well understood. Improving and applying synapse imaging we have obtained data shedding new light on the mechanisms impeding the initiation of movements. Here, we describe the principle elements of a relatively inexpensive approach to achieve single synapse resolution by using the new genetically encoded ultrafast glutamate sensor iGluu, wide-field optics, a scientific CMOS (sCMOS) camera, a 473 nm laser and a laser positioning system to evaluate the state of corticostriatal synapses in acute slices from age appropriate healthy or diseased mice. Glutamate transients were constructed from single or multiple pixels to obtain estimates of i) glutamate release based on the maximal elevation of the glutamate concentration [Glu] next to the active zone and ii) glutamate uptake as reflected in the time constant of decay (TauD) of the perisynaptic [Glu]. Differences in the resting bouton size and contrasting patterns of short-term plasticity served as criteria for the identification of corticostriatal terminals as belonging to the intratelencephalic (IT) or the pyramidal tract (PT) pathway. Using these methods, we discovered that in symptomatic HD mice ~40% of PT-type corticostriatal synapses exhibited insufficient glutamate clearance, suggesting that these synapses might be at risk to excitotoxic damage. The results underline the usefulness of TauD as a biomarker of dysfunctional synapses in Huntington mice with a hypokinetic phenotype.

We present a protocol to evaluate the balance between glutamate release and clearance at single corticostriatal glutamatergic synapses in acute slices from adult mice. This protocol uses the fluorescent sensor iGluu for glutamate detection, a sCMOS camera for signal acquisition and a device for focal laser illumination.

Indicadores únicos de sinapse de liberação de glutamato e absorção em fatias cerebrais agudas de ratos normais e huntington

Synapses are highly compartmentalized functional units that operate independently on each other. In Huntington&#39;s disease (HD) and other ...

Preparation of Acute Human Hippocampal Slices for Electrophysiological Recordings

Epilepsy affects about 1% of the world population and leads to a severe decrease in quality of life due to ongoing seizures as well as high risk for sudden death. Despite an abundance of available treatment options, about 30% of patients are drug-resistant. Several novel therapeutics have been developed using animal models, though the rate of drug-resistant patients remains unaltered. One of probable reasons is the lack of translation between rodent models and humans, such as a weak representation of human pharmacoresistance in animal models. Resected human brain tissue as a preclinical evaluation tool has the advantage to bridge this translational gap. Described here is a method for high quality preparation of human hippocampal brain slices and subsequent stable induction of epileptiform activity. The protocol describes the induction of burst activity during application of 8 mM KCl and 4-aminopyridin. This activity is sensitive to established AED lacosamide or novel antiepileptic candidates, such as dimethylethanolamine (DMEA). In addition, the method describes induction of seizure-like events in CA1 of human hippocampal brain slices by reduction of extracellular Mg2+ and application of bicuculline, a GABAA receptor blocker. The experimental set-up can be used to screen potential antiepileptic substances for their effects on epileptiform activity. Furthermore, mechanisms of action postulated for specific compounds can be validated using this approach in human tissue (e.g., using patch-clamp recordings). To conclude, investigation of vital human brain tissue ex vivo (here, resected hippocampus from patients suffering from temporal lobe epilepsy) will improve the current knowledge of physiological and pathological mechanisms in the human brain.

The presented protocol describes the transport and preparation of resected human hippocampal tissue with the ultimate goal to use vital brain slices as a preclinical evaluation tool for potential antiepileptic substances.

Preparação de fatias hipocampais humanas agudas para gravações eletrofisiológicas

Epilepsy affects about 1% of the world population and leads to a severe decrease in quality of life due to ongoing seizures as well as high risk for ...