Financiamento concedido pela Fundação Nacional de Ciência (IOS-1050701 para BAC), o National Institutes of Health (NS54174 a SM e F30DC0111907 a AML-W.), A Fundação Memorial Uehara e Sociedade Japonesa para a Promoção da Ciência (G2205 para TK ). Agradecemos Julian Meeks por seu apoio e orientação sobre o tema das gravações axonal extracelulares. Agradecemos Carl Hopkins para fornecer uma câmara de gravação protótipo.

<ol>
	<li>Meeks, J. P., Jiang, X., Mennerick, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Action+potential+fidelity+during+normal+and+epileptiform+activity+in+paired+soma-axon+recordings+from+rat+hippocampus.">Action potential fidelity during normal and epileptiform activity in paired soma-axon recordings from rat hippocampus.</a> J. Physiol. 566, 425-441 (2005).</li><li>Pinault, D. <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+single-cell+staining+procedure+performed+in+vivo+under+electrophysiological+control:+morpho-functional+features+of+juxtacellularly+labeled+thalamic+cells+and+other+central+neurons+with+biocytin+or+Neurobiotin.">A novel single-cell staining procedure performed in vivo under electrophysiological control: morpho-functional features of juxtacellularly labeled thalamic cells and other central neurons with biocytin or Neurobiotin.</a> J. Neurosci. Methods. 65, 113-136 (1996).</li><li>Joshi, S., Hawken, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loose-patch-juxtacellular+recording+in+vivo--a+method+for+functional+characterization+and+labeling+of+neurons+in+macaque+V1.">Loose-patch-juxtacellular recording in vivo--a method for functional characterization and labeling of neurons in macaque V1.</a> J. Neurosci. Methods. 156, 37-49 (2006).</li><li>Margrie, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+whole-cell+recordings+in+the+mammalian+brain+in+vivo.">Targeted whole-cell recordings in the mammalian brain in vivo.</a> Neuron. 39, 911-918 (2003).</li><li>Lima, S. Q., Hrom&#225;dka, T., Znamenskiy, P., Zador, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PINP:+A+new+method+of+tagging+neuronal+populations+for+identification+during+in+vivo+electrophysiological+recording.">PINP: A new method of tagging neuronal populations for identification during in vivo electrophysiological recording.</a> PLoS One. 4, e6099 (2009).</li><li>Foust, A., Popovic, M., Zecevic, D., McCormick, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Action+potentials+initiate+in+the+axon+initial+segment+and+propagate+through+axon+collaterals+reliably+in+cerebellar+Purkinje+neurons.">Action potentials initiate in the axon initial segment and propagate through axon collaterals reliably in cerebellar Purkinje neurons.</a> J. Neurosci. 30, 6891-6902 (2010).</li><li>Lehman, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Herpes+simplex+virus+as+a+transneuronal+tracer.">Herpes simplex virus as a transneuronal tracer.</a> Neurosci. Biobehav. Rev. 22, 695-708 (1998).</li><li>Joris, P. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+dogged+pursuit+of+coincidence.">A dogged pursuit of coincidence.</a> J. Neurophysiol. 96, 969-972 (2006).</li><li>Heiligenberg, W., Rose, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase+and+amplitude+computations+in+the+midbrain+of+an+electric+fish:+Intracellular+studies+of+neurons+participating+in+the+jamming+avoidance+response+of+Eigenmannia.">Phase and amplitude computations in the midbrain of an electric fish: Intracellular studies of neurons participating in the jamming avoidance response of Eigenmannia.</a> J. Neurosci. 5, 515-531 (1985).</li><li>Morales, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Releasing+the+peri-neuronal+net+to+patch-clamp+neurons+in+adult+CNS.">Releasing the peri-neuronal net to patch-clamp neurons in adult CNS.</a> Pfl&#252;gers Archiv European J. Physiol. 448, 248-258 (2004).</li><li>Friedman, M. A., Hopkins, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+substrates+for+species+recognition+in+the+time-coding+electrosensory+pathway+of+mormyrid+electric+fish.">Neural substrates for species recognition in the time-coding electrosensory pathway of mormyrid electric fish.</a> J. Neurosci. 18, 1171-1185 (1998).</li><li>Hitschfeld, &. #. 2. 0. 1. ;. M., Stamper, S. A., Vonderschen, K., Fortune, E. S., Chacron, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+restraint+and+immobilization+on+electrosensory+behaviors+of+weakly+electric+fish.">Effects of restraint and immobilization on electrosensory behaviors of weakly electric fish.</a> ILAR. J. 50, 361-372 (2009).</li><li>Xu-Friedman, M. A., Hopkins, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+mechanisms+of+temporal+analysis+in+the+knollenorgan+pathway+of+mormyrid+electric+fish.">Central mechanisms of temporal analysis in the knollenorgan pathway of mormyrid electric fish.</a> J. Exp. Biol. 202, 1311-1318 (1999).</li><li>Amagai, S., Friedman, M. A., Hopkins, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time+coding+in+the+midbrain+of+mormyrid+electric+fish.+I.+Physiology+and+anatomy+of+cells+in+the+nucleus+exterolateralis+pars+anterior.">Time coding in the midbrain of mormyrid electric fish. I. Physiology and anatomy of cells in the nucleus exterolateralis pars anterior.</a> J. Comp. Physiol. A: Neuroethol Sens Neural. Behav. Physiol. 182, 115-130 (1998).</li><li>Brady, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+technique+for+making+very+fine,+durable+dissecting+needles+by+sharpening+tungsten+wire+electrolytically.">A simple technique for making very fine, durable dissecting needles by sharpening tungsten wire electrolytically.</a> Bull World Health Organ. 2, 143-144 (1965).</li><li>Carlson, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal-pattern+recognition+by+single+neurons+in+a+sensory+pathway+devoted+to+social+communication+behavior.">Temporal-pattern recognition by single neurons in a sensory pathway devoted to social communication behavior.</a> J. Neurosci. 29, 9417-9428 (2009).</li><li>Mugnaini, E., Maler, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytology+and+immunocytochemistry+of+the+nucleus+extrolateralis+anterior+of+the+mormyrid+brain:+possible+role+of+GABAergic+synapses+in+temporal+analysis.">Cytology and immunocytochemistry of the nucleus extrolateralis anterior of the mormyrid brain: possible role of GABAergic synapses in temporal analysis.</a> Anat Embryol. (Berl). 176, 313-336 (1987).</li><li>Kohashi, T., Lyons-Warren, A. M., Mennerick, S., Carlson, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+submillisecond+spike+timing+differences+based+on+delay-line+anticoincidence+detection.">Detection of submillisecond spike timing differences based on delay-line anticoincidence detection.</a> J. Neurophysiol. 110, 2295-2311 (2013).</li><li>Colin, W., Donoff, R. B., Foote, W. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+latex+microspheres+as+a+retrograde+tracer+in+the+peripheral+nervous+system.">Fluorescent latex microspheres as a retrograde tracer in the peripheral nervous system.</a> Brain Res. 486, 334-339 (1989).</li><li>Katz, L. C., Burkhalter, A., Dreyer, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+latex+microspheres+as+a+retrograde+neuronal+marker+for+in+vivo+and+in+vitro+studies+of+visual+cortex.">Fluorescent latex microspheres as a retrograde neuronal marker for in vivo and in vitro studies of visual cortex.</a> Nature. 310, 498-500 (1984).</li><li>Brown, S. P., Hestrin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracortical+circuits+of+pyramidal+neurons+reflect+their+long-range+axonal+targets.">Intracortical circuits of pyramidal neurons reflect their long-range axonal targets.</a> Nature. 457, 1133-1136 (2009).</li><li>Drapeau, P., Ali, D. W., Buss, R. R., Saint-Amant, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+recording+from+identifiable+neurons+of+the+locomotor+network+in+the+developing+zebrafish.">In vivo recording from identifiable neurons of the locomotor network in the developing zebrafish.</a> J. Neurosci. Methods. 88, 1-13 (1999).</li><li>Pollak, G. D., Burger, R. M., Klug, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissecting+the+circuitry+of+the+auditory+system.">Dissecting the circuitry of the auditory system.</a> Trends Neurosci. 26, 33-39 (2003).</li><li>Wurtz, R. H., Albano, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual-motor+function+of+the+primate+superior+colliculus.">Visual-motor function of the primate superior colliculus.</a> Annu. Rev. Neurosci. 3, 189-226 (1980).</li><li>O'Malley, D. M., Zhou, Q., Gahtan, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+neural+circuits+in+the+zebrafish:+a+suite+of+optical+techniques.">Probing neural circuits in the zebrafish: a suite of optical techniques.</a> Methods. 30, 49-63 (2003).</li><li>Vercelli, A., Repici, M., Garbossa, D., Grimaldi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+techniques+for+tracing+pathways+in+the+central+nervous+system+of+developing+and+adult+mammals.">Recent techniques for tracing pathways in the central nervous system of developing and adult mammals.</a> Brain Res. Bull. 51, 11-28 (2000).</li><li>Ohki, K., Chung, S., Ch'ng, Y. H., Kara, P., Reid, 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=Functional+imaging+with+cellular+resolution+reveals+precise+micro-architecture+in+visual+cortex.">Functional imaging with cellular resolution reveals precise micro-architecture in visual cortex.</a> Nature. 433, 597-603 (2005).</li><li>Gahtan, E., O'Malley, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+lesioning+of+large+numbers+of+identified+vertebrate+neurons:+applications+in+zebrafish.">Rapid lesioning of large numbers of identified vertebrate neurons: applications in zebrafish.</a> J. Neurosci. Methods. 108, 97-110 (2001).</li><li>Higure, Y., Katayama, Y., Takeuchi, K., Ohtubo, Y., Yoshii, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lucifer+Yellow+slows+voltage-gated+Na++current+inactivation+in+a+light-dependent+manner+in+mice.">Lucifer Yellow slows voltage-gated Na+ current inactivation in a light-dependent manner in mice.</a> J. Physiol. 550, 159-167 (2003).</li><li>Mennerick, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+voltage-sensitive+dyes+modulate+GABAA+receptor+function.">Diverse voltage-sensitive dyes modulate GABAA receptor function.</a> J. Neurosc. 30, 2871-2879 (2010).</li><li>Oxford, G. S., Pooler, J. P., Narahashi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Internal+and+external+application+of+photodynamic+sensitizers+on+squid+giant+axons.">Internal and external application of photodynamic sensitizers on squid giant axons.</a> J. Membr. Biol. 36, 159-173 (1977).</li><li>Roberts, T. F., Tschida, K. A., Klein, M. E., Mooney, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+spine+stabilization+and+synaptic+enhancement+at+the+onset+of+behavioural+learning.">Rapid spine stabilization and synaptic enhancement at the onset of behavioural learning.</a> Nature. 463, 948-952 (2010).</li><li>Min, W., Freudiger, C. W., Lu, S., Xie, X. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coherent+nonlinear+optical+imaging:+beyond+fluorescence+microscopy.">Coherent nonlinear optical imaging: beyond fluorescence microscopy.</a> Annu. Rev. Phys. Chem. 62, 507-530 (2011).</li><li>Holekamp, T. F., Turaga, D., Holy, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+three-dimensional+fluorescence+imaging+of+activity+in+neural+populations+by+objective-coupled+planar+illumination+microscopy.">Fast three-dimensional fluorescence imaging of activity in neural populations by objective-coupled planar illumination microscopy.</a> Neuron. 57, 661-672 (2008).</li></ol>

Não há conflitos de interesse declarados.

Uma vez dominado, esta técnica permitirá um para atingir os neurônios identificados, incluindo axônios individuais, no gravações vivo em muitos sistemas modelo. Além disso, esta técnica permite registar com segurança de saída de pico de neurónios com características únicas que o tornam anatómicas tradicional em métodos de gravação vivo desafiador. Nós utilizamos esta técnica para gravar a partir de ELA &quot;pequenas células&quot; em mormyrid peixe fracamente elétrico. As tentativas anteriores para estudar as propriedades de ajuste de &quot;pequenas células&quot; não tiveram sucesso devido às condições desafiadoras de gravação 11, 14. Características anatômicas semelhantes criar barreiras para a obtenção de gravações em uma única unidade de diversos vertebrados neurônios electrosensory 8-10 e auditivos. Para superar estes desafios em nosso sistema, aproveitamos o fato de que &quot;pequenas células&quot; são as únicas células em ELA que se projetam para ELP. Assim, o transporte retrógrado de corante colocado no ELP limita rotulagem em ELA a &quot;pequena&quot;somas e axônios de células. marcação fluorescente dos axônios permitiu a colocação do eletrodo precisa ao lado de axônios marcados, fazendo gravações em uma única unidade de células identificadas possíveis apesar somas inacessíveis. Tentamos gravações somáticas, mas não tiveram sucesso, provavelmente devido às sinapses envolvendo em torno de 11 , 17. No entanto, a rotulagem somática era claramente visível, sugerindo que esta técnica pode ser usada para alvejar gravações somáticos em outros tipos celulares e outros circuitos. rotulagem fluorescente de neurónios através de transporte retrógrado in vivo, foi utilizado para orientar gravações alvo in vitro 19-21 . Uma técnica semelhante foi utilizada para alvo de gravações de neurónios motores in vivo em peixes-zebra medula espinal 22. nosso trabalho representa uma nova abordagem de expansão deste, em que ambos de rotulagem e gravação são feitas in vivo dentro do cérebro. nosso método demonstra que, in vivo rotulagem das áreas do sistema nervoso central com um retrógrado tpiloto pode ser expandido para o estudo de outros circuitos intactas com neurónios de projecção semelhante selectivos. Por exemplo, no tratamento de mamíferos auditivo, no colículo inferior (CI), que serve como um centro de retransmissão importante para as entradas de várias estruturas rhombencephalic 23. Injecção de corante para o IC seria etiquetar selectivamente as células de projecção a partir de cada um destes núcleos. O colículo superior (SC) tem uma função semelhante para a visão 24. Preparações da medula espinal são particularmente adequados para esta técnica, tal como a medula espinal é facilmente acessível, a injecção de corante pode ocorrer longe do local de gravação, e pode ser combinado com a gravação intracelular e enchimento de neurónios seleccionados para adquirir a informação anatómica mais detalhada 25. Finalmente, o tracto-tracing é uma técnica bem estabelecida utilizada em todo o sistema nervoso central para mapear complexo circuito 26. O método pode ser utilizado para adicionar a informação funcional para estes estudos, como tem sido feito windicadores de cálcio sensíveis om em cat córtex visual 27. A cirurgia, o que está bem estabelecido, fiável e, regularmente usado para cego in vivo gravações 16, deve ser preenchida com hemorragia mínima e sem danificar a superfície do cérebro para permitir que o animal e o tecido para sobreviver. Com a prática, a aplicação da cirurgia e corante pode ser completado em 30-45 minutos. Nós rotulado com sucesso &quot;pequenas células&quot; axônios em 67% dos preparativos. A maioria das preparações têm apenas 1 ou 2 axônios marcados visíveis, mas alguns têm até 8. Dos 119 unidades marcadas tentaram, obtivemos gravações-unitárias de 26 unidades distribuídas ao longo de 12 preparações (Tabela 2). Assim, os dados foram coletados a partir de 41% de preparações com axônios marcados para uma taxa global de sucesso de 28%. O aspecto crítico da aplicação corante é etiquetar profundidade. A falta de inserção do fio de tungsténio vai resultar em que o corante de ser lavado away. No entanto, se a penetração for muito profunda, axónios marcados não será visível para o direcionamento. Além disso, alguns danos mecânicos na célula deve ocorrer para que o corante deve ser adequadamente feita até 25, 28. No entanto, muito dano vai matar as células. Tentamos marcação com outros corantes e outros métodos (Tabela 2), incluindo a rotulagem anterógrada através de injeção de corante em ELA emparelhado com gravação de axônios marcados em ELP (Tabela 3). Nossa hipótese é que a rotulagem anterógrada não foi bem sucedida porque a rotulagem foi limitada a células com danos somática, tornando-se indiferente. Além disso, os terminais pré-sinápticas podem ter sido perturbada. Em contraste, marcação retrógrada minimiza tanto destas preocupações. A quantidade e localização de aplicação de corante pode ser alterado de acordo com o circuito particular a ser estudado. Rotulagem máxima ocorre com a maior concentração de corante, o que foi conseguido usando fios de tungsténio revestidas. No entanto, para a rotulagem de axônios comprojeções ep, corante pode sair de uma agulha de tungstênio como é avançado. Nestes casos, a injecção de pressão seria mais apropriada. Absorção e transporte Dye são rápidos, com axônios marcados em nossa preparação, sendo visível logo em 2 horas após a injeção e axônios marcados adicionais que aparecem tão tarde quanto 6 horas após a injeção. Assim, a marcação e gravação pode ser realizada num único dia, eliminando dificuldades técnicas associadas com a cirurgia de sobrevivência. Sincronismo irá variar para cada aplicação, dependendo da distância necessária para o transporte de corante. Outro aspecto importante é a colocação do eletrodo. É importante para entrar no tecido próximo do sítio do axónio rotulado para evitar o entupimento da ponta. Para o tecido denso, tal como na ELA, uma longa haste fina no eléctrodo de registo minimiza o excesso de movimento do tecido circundante. Se uma gravação de sucesso não é alcançado na primeira tentativa, repita com eletrodos frescas até uma gravação é obtida ou a TISSue é interrompida para o ponto no qual o axónio já não é visível. No entanto, é também importante para colocar rapidamente o eléctrodo próximo ao axónio para minimizar a quantidade de exposição fluorescente, o que pode causar a fototoxicidade, branqueamento e pode afectar as propriedades fisiológicas da célula 29-31. Uma vez que um segmento do axónio é aspirada com êxito no eléctrodo de registo, as gravações podem ser obtidos por várias horas. Se as unidades são constantemente perdidos em menos de 1 hora, considere fazer pontas de eléctrodos mais pequenos para impedir o axónio de deslizar para fora. Por outro lado, muito pequena de um ponta pode resultar em entupimento, baixo sinal-ruído, ou danos no axónio. Uma diminuição constante no pico de amplitude e o &quot;retorno&quot; de uma unidade de sucção é uma indicação adicional de que a ponta é demasiado grande. Muito sucção pode causar danos irreparáveis ​​para o axônio. Uma solução é permitir que uma pequena fuga na linha de ar de modo a pressão lentamente retorna a zero. Rapidamente equalizar ªe pressão irá resultar em uma relação transitória-fora &#39;push&#39; que pode expulsar o axônio. Embora esta técnica representa uma grande vantagem para a obtenção de gravações específicas identificadas a partir de neurónios de projecção, que não será útil para distinguir interneurónios locais, como corante seria ocupada por todos os tipos de células no local da injecção. Teoricamente, a utilização de fluoróforos com múltiplos locais de injecção pode permitir que este método seja expandida. Por exemplo, a comparação de um único versus dupla marcação pode ser usado para distinguir interneurónios de neurónios de projecção dupla seguintes injecções em dois pontos no circuito 32. Da mesma forma, traçadores retrógrados pode ser combinada com outras técnicas de imagem avançadas, como a imagem de dois fótons, como foi feito recentemente em tentilhão alta centro Vocal (HVC) 32. Além disso, as regiões de gravação são limitados aqueles que perto da superfície quando se utiliza microscópios de epifluorescência, já que só foram capazes de resolver uma emu; estruturas m nos primeiros 30 mm de tecido. No entanto, esta profundidade poderia ser estendido através da utilização de outras técnicas de microscopia, tais como a microscopia de dois fotões 33 ou objectivo acoplado a microscopia de iluminação plana 34. No geral, esta técnica representa um avanço importante no estudo dos circuitos neuronais in vivo, porque pode ser utilizado para gravar a partir de neurónios individuais, em muitos circuitos diferentes em uma variedade de sistemas de modelos - incluindo aqueles que são relativamente inacessíveis.

<table border="1" cellspacing="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Tricaine Methanesulfonate</td>
 <td>Sigma-Aldrich</td>
 <td>E10521</td>
 <td>MS-222</td>
 </tr>
 <tr>
 <td>Gallamine Triethiodide </td>
 <td>Sigma-Aldrich</td>
 <td>G8134</td>
 <td>Flaxedil</td>
 </tr>
 <tr>
 <td>Lidocaine Hydrochloride</td>
 <td>Sigma-Aldrich</td>
 <td>L5647</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Hickman's Ringer Solution </td>
 <td>NA</td>
 <td>NA</td>
 <td>NaCl (6.48 g/l), KCl (0.15 g/l), CaCl2&bull;2H20 (0.29 g/l), MgSO4 (0.12 g/l), NaHCO3 (0.084 g/l), NaH2PO4 (0.06 g/l)</td>
 </tr>
 <tr>
 <td>Peristaltic Pump</td>
 <td>Gilson or Rainin</td>
 <td>Minipulse 3 Model 312; RP-1</td>
 <td>10.0 &plusmn; 1.0 rpm, Alternatively, a gravity-fed line with a flow-meter</td>
 </tr>
 <tr>
 <td>Dissection Microscope </td>
 <td>Nikon</td>
 <td>SM2645</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Super Glue</td>
 <td>Super Glue Corporation</td>
 <td>SGH2</td>
 <td>2g tube</td>
 </tr>
 <tr>
 <td>Omni Drill 35</td>
 <td>World Precision Instruments</td>
 <td>503-598</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Ball Mill Carbide Drill Bit #1/4</td>
 <td>World Precision Instruments</td>
 <td>501860</td>
 <td>0.19 DIA (bit diameter = 0.48 mm) </td>
 </tr>
 <tr>
 <td>Low Temp Cautery Kit</td>
 <td>World Precision Instruments</td>
 <td>500391</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Manual Micromanipulator</td>
 <td>World Precision Instruments</td>
 <td>M3301R</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Dextran Conjugated Alexa Fluor 568</td>
 <td>Invitrogen</td>
 <td>D-22912</td>
 <td>2mM concentration; 10,000MW The choice of dye wavelength should be selected to match the microscope filter settings</td>
 </tr>
 <tr>
 <td>Epifluorescent Microscope</td>
 <td>Nikon </td>
 <td>E600 FN</td>
 <td>A remote focus accessory is helpful for fine focus TRITC filter - or appropriate filter to match focal planes for different dye wavelengths</td>
 </tr>
 <tr>
 <td>Low Power Objective</td>
 <td>Nikon</td>
 <td>93182</td>
 <td>CFI Plan Achromat Series, 4X N.A. 0.1, W.D. 30mm</td>
 </tr>
 <tr>
 <td>High Power Objective</td>
 <td>Nikon</td>
 <td>93148</td>
 <td>CFI Fluor Series, 40X WI N.A. 0.8, W.D. 2.0 mm</td>
 </tr>
 <tr>
 <td>White Light Source</td>
 <td>Dolan-Jenner</td>
 <td>Model 190</td>
 <td>Fiber Optic Illuminator</td>
 </tr>
 <tr>
 <td>Fluorescent Light Source </td>
 <td>Lumen Dynamics</td>
 <td>X-Cite 120Q</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Low-light Level Camera</td>
 <td>Photometrics</td>
 <td>CoolSnap ES</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Digital Manometer</td>
 <td>Omega Engineering</td>
 <td>HHP-201</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Motorized Micromanipulator</td>
 <td>Sutter Instruments</td>
 <td>MP-285</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Headstage</td>
 <td>Molecular Devices</td>
 <td>CV-7B</td>
 <td>Axon Instruments</td>
 </tr>
 <tr>
 <td>Amplifier</td>
 <td>Molecular Devices</td>
 <td>MultiClamp 700B</td>
 <td>Axon Instruments</td>
 </tr>
 <tr>
 <td>Data Acquisition System</td>
 <td>Molecular Devices</td>
 <td>Digidata 1322A</td>
 <td>Axon Instruments</td>
 </tr>
 <tr>
 <td>Isolated Pulse Stimulator</td>
 <td>A-M Systems</td>
 <td>2100</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Flaming/Brown Micropipette Puller</td>
 <td>Sutter Instruments</td>
 <td>P-97</td>
 <td>Program settings for our application: Heat: ramp + 1, Pull: '0', Velocity: 60, Time: 90 Box filament</td>
 </tr>
 <tr>
 <td>Pipette Glass</td>
 <td>World Precision Instruments</td>
 <td>1B100F-4</td>
 <td>Borosilicate capillary glass with filament (1 mm OD, 0.58 mm ID) </td>
 </tr>
 </tbody>
</table>

retrograde fluorescent labeling allows for targeted extracellular single-unit recording from identified neurons in vivo

O objetivo geral deste método é o de registrar as respostas única unidade de uma população identificada de neurônios. Nos registros eletrofisiológicos in vivo dos neurônios individuais são fundamentais para a compreensão de como os circuitos neurais funcionam em condições naturais. Tradicionalmente, estes registos foram efectuados &quot;cego&quot;, o que significa a identidade da célula registada é desconhecido no início da gravação. Identidade celular pode ser posteriormente determinada via intracelular 1, juxtacellular 2 ou solta-patch 3 iontoforese de corante, mas estas gravações não podem ser pré-alvejado a neurônios específicos em regiões com tipos de células funcionalmente heterogêneos. As proteínas fluorescentes podem ser expressas de uma forma específica do tipo de célula permitindo visualmente guiada electrofisiologia unicelular 4-6. No entanto, existem muitos sistemas modelo para o qual estas ferramentas genéticas não estão disponíveis. Mesmo em sistemas modelo geneticamente acessíveis, o desejado promoter pode ser desconhecido ou neurônios geneticamente homogêneos pode ter diferentes padrões de projeção. Do mesmo modo, os vectores virais têm sido utilizados para etiquetar subgrupos específicos de neurónios de projecção 7, mas a utilização deste método é limitada pela toxicidade e falta de especificidade trans-sináptica. Assim, são necessárias técnicas adicionais que oferecem pré-visualização específico para gravar a partir de neurônios individuais identificados in vivo. Pré-visualização do neurônio alvo é particularmente útil para condições de gravação difíceis, para que as gravações de uma única célula clássicos muitas vezes são proibitivamente difícil 8-11. A nova técnica descrita neste artigo usa transporte retrógrado de um corante fluorescente aplicada com o uso de agulhas de tungstênio para rotular rapidamente e seletivamente um subconjunto específico de células dentro de uma determinada região do cérebro com base em suas projeções axonais únicos, proporcionando assim uma indicação visual para obter registros eletrofisiológicos alvo de neurônios identificados em um circuito intacto withind vertebrado SNC. O novo avanço mais significativo do nosso método é a utilização de rotulagem fluorescente para atingir tipos celulares específicos num sistema modelo acessíveis não geneticamente. Peixe fracamente elétrico é um sistema excelente modelo para o estudo de circuitos neurais no acordado, comportando 12 animais. Nós utilizamos esta técnica para estudar o processamento sensorial por &quot;pequenas células&quot; no núcleo exterolateral anterior (ELA) de peixes mormyrid fracamente elétrico. &quot;Pequenas células&quot; são supor para ser tempo de comparação neurônios importantes para a detecção de diferenças submillisecond nos tempos de chegada dos picos pré-sinápticos 13. No entanto, as características anatômicas, como mielina denso, engolindo as sinapses, e os corpos de pequenas células tornaram extremamente difícil para gravar a partir destas células através de métodos tradicionais 11, 14. Aqui demonstramos que o nosso novo método seletivamente rotula essas células em 28% das preparações, permitindo confiáveis, robustos e gravações caracteríszação das respostas à estimulação electrosensory.

Watch this Scientific Journal Video about Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo at JoVE.com

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Transporte retrógrado de corante fluorescente rotula uma sub-população de neurónios baseado em projecção anatómica. Axônios rotulados pode ser alvo visualmente<em&gt; In vivo</em&gt;, Permitindo a gravação extracelular de axónios identificados. Esta técnica permite a gravação quando os neurónios não podem ser marcados através de manipulação genética ou são difíceis de isolar usando &quot;cega&quot;<em&gt; In vivo</em&gt; Abordagens.

Labeling fluorescentes retrógrada Permite alvejado Extracelular Gravação Single-unidade dos neurônios identificados<em&gt; In vivo</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

retrograde-fluorescent-labeling-allows-for-targeted-extracellular

Research

JoVE Journal

Neuroscience

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

19.8K visualizações.  Washington University in St. Louis. Transporte retrógrado de corante fluorescente rotula uma sub-população de neurónios baseado em projecção anatómica. Axônios rotulados pode ser alvo visualmente In vivo, Permitindo a gravação extracelular de axónios identificados. Esta técnica permite a gravação quando os neurónios não podem ser marcados através de manipulação genética ou são difíceis de isolar usando "cega" In vivo Abordagens.

Vídeo: Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Dual Somatic Recordings from Gonadotropin-Releasing Hormone (GnRH) Neurons Identified by Green Fluorescent Protein (GFP) in Hypothalamic Slices

Gonadotropin-Releasing Hormone (GnRH) is a small neuropeptide that regulates pituitary release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These gonadotropins are essential for the regulation of reproductive function. The GnRH-containing neurons are distributed diffusely throughout the hypothalamus and project to the median eminence where they release GnRH from their axon terminals into the hypophysiotropic portal system (1). In the portal capillaries, GnRH travels to the anterior pituitary gland to stimulate release of gonadotropins into systemic circulation. GnRH release is not continuous but rather occurs in episodic pulses. It is well established that the intermittent manner of GnRH release is essential for reproduction (2, 3).
Coordination of activity of multiple GnRH neurons probably underlies GnRH pulses. Total peptide content in GnRH neurons is approximately 1.0 pg/cell (4), of which 30% likely comprises the releasable pool. Levels of GnRH during a pulse (5, 6), suggest multiple GnRH neurons are probably involved in neurosecretion. Likewise, single unit activity extracted from hypothalamic multi-unit recordings during LH release indicates changes in activity of multiple neurons (7). The electrodes with recorded activity during LH pulses are associated with either GnRH somata or fibers (8). Therefore, at least some of this activity arises from GnRH neurons.
The mechanisms that result in synchronized firing in hypothalamic GnRH neurons are unknown. Elucidating the mechanisms that coordinate firing in GnRH neurons is a complex problem. First, the GnRH neurons are relatively few in number. In rodents, there are 800-2500 GnRH neurons. It is not clear that all GnRH neurons are involved in episodic GnRH release. Moreover, GnRH neurons are diffusely distributed (1). This has complicated our understanding of coordination of firing and has made many technical approaches intractable. We have optimized loose cell-attached recordings in current-clamp mode for the direct detection of action potentials and developed a recording approach that allows for simultaneous recordings from pairs of GnRH neurons.

Dual Somatic Recordings from Gonadotropin-Releasing Hormone GnRH Neurons Identified by Green Fluorescent Protein GFP in Hypothalamic Slices

Activity in neuronal systems often requires synchronous action potential discharges from neurons within a specific population. For example, pulses of gonadotropin-releasing hormone (GnRH) likely require coordinated activity between GnRH neurons. We present our methodological approach for reliably obtaining simultaneous electrophysiological recordings from the diffusely distributed GnRH neurons.

Dupla Recordings somática de Hormônio Liberador de Gonadotropina (GnRH) Neurônios Identificados por proteína verde fluorescente (GFP) em fatias Hypothalamic

Gonadotropin-Releasing Hormone (GnRH) is a small neuropeptide that regulates pituitary release of luteinizing hormone (LH) and follicle-stimulating ...

Neurociência

Single-unit In vivo Recordings from the Optic Chiasm of Rat

Information about the visual world is transmitted to the brain in sequences of action potentials in retinal ganglion cell axons that make up the optic nerve. In vivo recordings of ganglion cell spike trains in several animal models have revealed much of what is known about how the early visual system processes and encodes visual information. However, such recordings have been rare in one of the most common animal models, the rat, possibly owing to difficulty in detecting spikes fired by small diameter axons. The many retinal disease models involving rats motivate a need for characterizing the functional properties of ganglion cells without disturbing the eye, as with intraocular or in vitro recordings. Here, we demonstrate a method for recording ganglion cell spike trains from the optic chiasm of the anesthetized rat. We first show how to fabricate tungsten-in-glass electrodes that can pick up electrical activity from single ganglion cell axons in rat. The electrodes outperform all commercial ones that we have tried. We then illustrate our custom-designed stereotaxic system for in vivo visual neurophysiology experiments and our procedures for animal preparation and reliable and stable electrode placement in the optic chiasm.

Single-unit In vivo Recordings from the Optic Chiasm of Rat

Retinal ganglion cells transmit visual information from the eye to the brain with sequences of action potentials. Here, we demonstrate how to record the action potentials of single ganglion cells in vivo from anesthetized rats.

Única unidade de In vivo Gravações do quiasma óptico de rato

Information about the visual world is transmitted to the brain in sequences of action potentials in retinal ganglion cell axons that make up the optic ...

Surgical Implantation of Chronic Neural Electrodes for Recording Single Unit Activity and Electrocorticographic Signals

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery. Here we provide useful information for surgeons who are learning the process of implanting electrode systems. We demonstrate the implantation procedure of both a penetrating and a surface electrode. The surgical process is described from start to finish, including detailed descriptions of each step throughout the procedure. It should also be noted that this video guide is focused towards procedures conducted in rodent models and other small animal models. Modifications of the described procedures are feasible for other animal models.

We provide useful information for surgeons who are learning the process of implanting chronic neural recording electrodes. Techniques for both penetrating and surface electrode systems are described in a rodent animal model.

Implante cirúrgico de crônicas Eletrodos Neurais para registrar a atividade única Unidade e Sinais eletrocorticográfica

The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery.  Here we provide useful information for ...

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated. Thus, simultaneous recordings of neuronal activity and behavior are essential to correlate brain activity to behavior. For such behavioral analyses, the fruit fly, Drosophila melanogaster, allows us to incorporate genetically encoded calcium indicators such as GCaMP1, to monitor neuronal activity, and to use sophisticated genetic manipulations for optogenetic or thermogenetic techniques to specifically activate identified neurons2-5. Use of a thermogenetic technique has led us to find critical neurons for feeding behavior (Flood et al., under revision). As a main part of feeding behavior, a Drosophila adult extends its proboscis for feeding6 (proboscis extension response; PER), responding to a sweet stimulus from sensory cells on its proboscis or tarsi. Combining the protocol for PER7 with a calcium imaging technique8 using GCaMP3.01, 9, I have established an experimental system, where we can monitor activity of neurons in the feeding center &#x2013; the suboesophageal ganglion (SOG), simultaneously with behavioral observation of the proboscis. I have designed an apparatus ("Fly brain Live Imaging and Electrophysiology Stage": "FLIES") to accommodate a Drosophila adult, allowing its proboscis to freely move while its brain is exposed to the bath for Ca2+ imaging through a water immersion lens. The FLIES is also appropriate for many types of live experiments on fly brains such as electrophysiological recording or time lapse imaging of synaptic morphology. Because the results from live imaging can be directly correlated with the simultaneous PER behavior, this methodology can provide an excellent experimental system to study information processing of neuronal networks, and how this cellular activity is coupled to plastic processes and memory.

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

The fruit fly, Drosophila melanogaster, extends its proboscis for feeding, responding to a sugar stimulus from its proboscis or tarsus. I have combined observations of the proboscis extension response (PER) with a calcium imaging technique, allowing us to monitor the activity of neurons in the brain, simultaneously with behavioral observation.

De gravação simultânea de sinais de cálcio dos neurônios identificados e comportamento alimentar de Drosophila melanogaster</em

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated.  Thus, ...

Retrograde Loading of Nerves, Tracts, and Spinal Roots with Fluorescent Dyes

Retrograde labeling of neurons is a standard anatomical method1,2 that has also been used to load calcium and voltage-sensitive dyes into neurons3-6. Generally, the dyes are applied as solid crystals or by local pressure injection using glass pipettes. However, this can result in dilution of the dye and reduced labeling intensity, particularly when several hours are required for dye diffusion. Here we demonstrate a simple and low-cost technique for introducing fluorescent and ion-sensitive dyes into neurons using a polyethylene suction pipette filled with the dye solution. This method offers a reliable way for maintaining a high concentration of the dye in contact with axons throughout the loading procedure.

We describe a simple and low cost technique for introducing high concentration of fluorescent and calcium-sensitive dyes into neurons or any neuronal tract using a polyethylene suction pipette.

Carregando retrógrado de Nervos, folhetos, e raízes nervosas com corantes fluorescentes

Retrograde labeling of neurons is a standard anatomical method1,2 that has also been used to load calcium and voltage-sensitive dyes into neurons3-6. ...

Recording Electrical Activity from Identified Neurons in the Intact Brain of Transgenic Fish

Understanding the cell physiology of neural circuits that regulate complex behaviors is greatly enhanced by using model systems in which this work can be performed in an intact brain preparation where the neural circuitry of the CNS remains intact. We use transgenic fish in which gonadotropin-releasing hormone (GnRH) neurons are genetically tagged with green fluorescent protein for identification in the intact brain. Fish have multiple populations of GnRH neurons, and their functions are dependent on their location in the brain and the GnRH gene that they express1 . We have focused our demonstration on GnRH3 neurons located in the terminal nerves (TN) associated with the olfactory bulbs using the intact brain of transgenic medaka fish (Figure 1B and C). Studies suggest that medaka TN-GnRH3 neurons are neuromodulatory, acting as a transmitter of information from the external environment to the central nervous system; they do not play a direct role in regulating pituitary-gonadal functions, as do the well-known hypothalamic GnRH1 neurons2, 3 .The tonic pattern of spontaneous action potential firing of TN-GnRH3 neurons is an intrinsic property4-6, the frequency of which is modulated by visual cues from conspecifics2 and the neuropeptide kisspeptin 15. In this video, we use a stable line of transgenic medaka in which TN-GnRH3 neurons express a transgene containing the promoter region of Gnrh3 linked to enhanced green fluorescent protein7 to show you how to identify neurons and monitor their electrical activity in the whole brain preparation6.

In this video, we will demonstrate how to record electrical activity from identified single neurons in a whole brain preparation, which preserves complex neural circuits. We use transgenic fish in which gonadotropin-releasing hormone (GnRH) neurons are genetically tagged with a fluorescent protein for identification in the intact brain preparation.

Registro da atividade elétrica dos neurônios identificados no cérebro intacto de peixes transgénicos

Understanding the cell physiology of neural circuits that regulate complex behaviors is greatly enhanced by using model systems in which this work can be ...

Intracellular Recording, Sensory Field Mapping, and Culturing Identified Neurons in the Leech, Hirudo medicinalis

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from the ganglion to be cultured in a Petri dish, and how to record from those neurons in culture. Then we demonstrate how to prepare a patch of innervated skin to be used for mapping sensory or motor fields. These leech preparations are still widely used to address basic electrical properties of neural networks, behavior, synaptogenesis, and development. They are also an appropriate training module for neuroscience or physiology teaching laboratories.

Intracellular Recording, Sensory Field Mapping, and Culturing Identified Neurons in the Leech, Hirudo medicinalis

This article describes three nervous system preparations using leeches: intracellular recording from neurons in ventral ganglia, culturing neurons from ventral ganglia, and recording from a patch of innervated skin to map sensory fields.

Intracelular de gravação, Sensorial Campo Mapping, e cultivando neurônios identificados nos Sanguessuga, Hirudo medicinalis</i

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of ...

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

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

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

Marcação retrógrada de células ganglionares da retina em Zebrafish Adulto com corantes fluorescentes

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

A Guide to In vivo Single-unit Recording from Optogenetically Identified Cortical Inhibitory Interneurons

A major challenge in neurophysiology has been to characterize the response properties and function of the numerous inhibitory cell types in the cerebral cortex. We here share our strategy for obtaining stable, well-isolated single-unit recordings from identified inhibitory interneurons in the anesthetized mouse cortex using a method developed by Lima and colleagues1. Recordings are performed in mice expressing Channelrhodopsin-2 (ChR2) in specific neuronal subpopulations. Members of the population are identified by their response to a brief flash of blue light. This technique &#8211; termed &#8220;PINP&#8221;, or Photostimulation-assisted Identification of Neuronal Populations &#8211; can be implemented with standard extracellular recording equipment. It can serve as an inexpensive and accessible alternative to calcium imaging or visually-guided patching, for the purpose of targeting extracellular recordings to genetically-identified cells. Here we provide a set of guidelines for optimizing the method in everyday practice. We refined our strategy specifically for targeting parvalbumin-positive (PV+) cells, but have found that it works for other interneuron types as well, such as somatostatin-expressing (SOM+) and calretinin-expressing (CR+) interneurons.

A Guide to In vivo Single-unit Recording from Optogenetically Identified Cortical Inhibitory Interneurons

Here we describe our strategy for obtaining stable, well-isolated single-unit recordings from identified inhibitory interneurons in the anesthetized mouse cortex. Neurons expressing ChR2 are identified by their response to blue light. The method uses standard extracellular recording equipment, and serves as an inexpensive alternative to calcium imaging or visually-guided patching.

Um Guia para<em&gt; In vivo</em&gt; Gravação única unidade de Optogenetically Identificado Cortical Inibitória Interneurônios

A major challenge in neurophysiology has been to characterize the response properties and function of the numerous inhibitory cell types in the cerebral ...

Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identified Odorant Receptor

Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of olfactory-driven behaviors and their modulation. These coding properties depend heavily on the initial interaction between odor molecules and the olfactory receptor (OR) expressed in the OSNs. The identity, specificity and ligand spectrum of the expressed OR are critical. The probability to find the ligand of the OR expressed in an OSN chosen randomly within the epithelium is very low. To address this challenge, this protocol uses genetically tagged mice expressing the fluorescent protein GFP under the control of the promoter of defined ORs. OSNs are located in a tight and organized epithelium lining the nasal cavity, with neighboring cells influencing their maturation and function. Here we describe a method to isolate an intact olfactory epithelium and record through patch-clamp recordings the properties of OSNs expressing defined odorant receptors. The protocol allows one to characterize OSN membrane properties while keeping the influence of the neighboring tissue. Analysis of patch-clamp results yields&#160;a precise quantification of ligand/OR interactions, transduction pathways and pharmacology, OSNs&#39; coding properties and their modulation at the membrane level.&#160;

Analyzing the physiological properties of olfactory sensory neurons still faces technical limitations. Here we record them through perforated patch-clamp in an intact preparation of the olfactory epithelium in gene-targeted mice. This technique allows the characterization of membrane properties and responses to specific ligands of neurons expressing defined olfactory receptors.

Perfurado gravação patch-clamp de rato Olfactory neurônios sensoriais na Intact neuroepitélio: Análise Funcional do Neurônios Expressando uma Odorant Receptor Identificados

Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of ...