The authors thank Drs. Jeffrey Bloomquist and Daniel Swale for their technical comments and suggestions. This project was partially funded by the Department of Entomology and the College of Agriculture and Life Sciences at Virginia Tech.

1. Recolha e Preparação de assuntos de teste <ol><li> Coletar o número apropriado de abelhas da colônia. NOTA: O número necessário depende não só do tamanho e escopo do experimento, mas também da habilidade do investigador. Por exemplo, se existem 2 grupos de tratamento com um tamanho de amostra desejada de 10 abelhas em cada grupo, um investigador razoavelmente habilidoso pode recolher pelo menos 30 abelhas para explicar dissecções sem sucesso e acabar com 20 vídeos úteis para marcar. </li><li> Minimizar a quantidade de tempo que passa entre a recolha e dissecção. Nota: Embora as abelhas podem ser alojados no laboratório para os dias anteriores à dissecção, a taxa de sucesso de dissecção (isto é, a probabilidade de manter uma taxa cardíaca estável num vaso dorsal dissecados) foi observada para diminuir em relação à quantidade de tempo que abelhas estão alojados longe da colônia. <ol><li> Fornecer abelhas com uma fonte de água e comida, enquanto alojada no laboratório. para example, no mínimo, proporcionar o acesso a uma 50% de solução de sacarose em água (v / W) (isto é suficiente para durações de menos de 6 horas). Para períodos mais longos, fornecer abelhas acesso ao mel. </li><li> abelhas casa na noite de laboratório a uma temperatura de aproximadamente 32 ° C e 60-80% de umidade relativa para reduzir o estresse e evitar a desidratação. </li></ol></li><li> Antes de dissecação, anestesiar abelhas brevemente para auxiliar no manuseio. NOTA: Isso pode diminuir a taxa de sucesso das dissecções e reduzir a taxa de transferência. <ol><li> Relaxar as abelhas, quer por colocá-los em gelo ou em uma geladeira por apenas o tempo suficiente para reduzir o movimento, a fim de auxiliar no manuseio. </li><li> Alternativamente, expor brevemente abelhas ao CO 2, a fim de auxiliar no manuseio. NOTA: A exposição prolongada ao frio pode reduzir a taxa de sucesso de dissecações. Estendida ou repetida exposição ao CO 2 também pode reduzir a taxa de sucesso de dissecações. </li></ol></li></ol> 2. Dissecçãoda Dorsal da parede abdominal NOTA: As abelhas devem estar vivo no momento da dissecção. <ol><li> Utilizando uma pinça e / ou tesoura de microdissecção, retire as pernas e asas para facilitar a dissecção do abdômen. Manter um pequeno copo ou recipiente semelhante preenchido com água destilada nas proximidades para fins de enxaguamento instrumentos entre dissecações. </li><li> Enquanto restringem a abelha com uma pinça, utilizar a tesoura para cortar microdissecção lateralmente ao longo da parede abdominal dorsal entre as primeira e segunda tergites (ver Figura 1). </li></ol><img alt="figura 1" src="/files/ftp_upload/55029/55029fig1.jpg" /> Figura 1: Vista dorsal do abdômen abelha. A incisão inicial pode ser feita entre os primeiro e segundo tergites, como indicado pela linha vermelha. Escala da barra = 1 mm. <a href="http://ecsource.jove.com/files/ftp_upload/55029/55029fig1large.jpg" target="_blank">Por favor, clique dela</a>e para ver uma versão maior desta figura. <ol start="3"><li> Enquanto levemente agarrando a borda posterior do segundo tergito com a pinça, cortado longitudinalmente ao longo de cada lado da abelha da incisão inicial para o aguilhão (ver Figura 2). Tenha cuidado ao cortar para evitar a perfuração do trato gastrointestinal. </li></ol><img alt="Figura 2" src="/files/ftp_upload/55029/55029fig2.jpg" /> Figura 2: Vista lateral do abdômen abelha. Os segundo e terceiro incisões devem ser feitas ao longo de cada lado do abdómen, como indicado pela linha vermelha. Escala da barra = 1 mm. <a href="http://ecsource.jove.com/files/ftp_upload/55029/55029fig2large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> <ol start="4"><li> Trocar a tesoura para um segundo conjunto de pinça fina e utilizá-los para separar cuidadosamente parede abdominal dorsal do resto of abdômen. Suavemente remover o ferrão e qualquer parte do tracto gastrintestinal que se mantém ligado à parede abdominal dorsal. Evitar a ruptura do intestino, como o conteúdo pode revestir a parede abdominal e impedir a visualização do vaso dorsal. </li></ol><img alt="Figura 3" src="/files/ftp_upload/55029/55029fig3.jpg" /> Figura 3: Vista do vaso dorsal. Uma vez que o intestino e ferrão ter sido removida, o vaso dorsal é visível ao longo da linha média da parede abdominal dorsal dissecados. Escala da barra = 1 mm. <a href="http://ecsource.jove.com/files/ftp_upload/55029/55029fig3large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> <ol start="5"><li> Organizar a parede abdominal dorsal na orientação desejada por baixo da câmara de modo que o vaso dorsal é visível (veja a Figura 3). Utilizar a tesoura de microdissecção para aparar qualquer excesso de abdominal parede impede que a visualização do vaso dorsal. A forma da parede abdominal dorsal deve se assemelhar a um copo ou tigela rasa quando bem situado. <ol><li> Uma vez que o vaso dorsal não se estender para o segmento abdominal mais atrás da abelha, remover o tergito final a fim de melhorar a visualização do vaso dorsal. </li></ol></li><li> Utilizando uma micropipeta de volume ajustável, cobrir o vaso dorsal com 10 ml de uma solução isotônica para manter as condições fisiológicas e facilitar uma pulsação constante. NOTA: A solução recomendada é de solução de Ringer força trimestre (0,120 g de cloreto de / L de cálcio, 0,105 g / L de cloreto de potássio, 0,050 g / L de bicarbonato de sódio e 2,250 g / L de cloreto de sódio), o qual foi encontrado para facilitar um estábulo, batimento cardíaco contínuo. </li></ol> 3. Observação e Modulação de Frequência Cardíaca <ol><li> Permitir que o vaso dorsal para repousar até que um batimento cardíaco estável, contínua é alcançada(Geralmente dentro de 300 segundos). NOTA: A pulsação do coração é visualizado como contrações rítmicas do vaso dorsal. Inicialmente, pode não parecem ser batimento cardíaco, especialmente se a abelha foi anestesiado, mas o coração bater normalmente será retomada após o repouso em solução isotónica durante vários minutos, e pode continuar a bater por hora, desde que se mantenha banhadas em solução. </li><li> Medir o ritmo cardíaco em termos do número de batimentos por minuto (BPM). <ol><li> Grave o número de contrações observados durante um período de 60 segundos. Use um contador de contagem de mão e um temporizador para facilitar este processo. </li></ol></li><li> Medir a alteração da frequência cardíaca pelo registro da BPM observados antes e após o tratamento com um composto cardiomodulatory. Nota: Embora o tempo necessário para se observar um efeito sobre a frequência cardíaca pode variar dependendo do composto a ser testado, as mudanças no ritmo cardíaco pode tipicamente ser observado no prazo de minutos. <ol><li> Determinar a frequência cardíaca basal imediatamente antes daa adição de qualquer composto de ensaio. NOTA: frequência cardíaca pós-tratamento geralmente pode ser determinada após 90 a 120 segundos. </li><li> Prepare cardiomodulators potenciais (por exemplo, octopamina) por dissolução do composto na mesma solução isotónica utilizados para banhar o vaso dorsal. </li><li> Adicionar os compostos de teste para a solução envolvente do vaso dorsal utilizando um micropipetter. </li></ol></li><li> Para maior precisão e maior rendimento, faça uma gravação de vídeo de cada assunto de teste e, em seguida, usar os vídeos para marcar frequência cardíaca em um momento posterior. NOTA: Este permite que um único investigador para escalonar dissecações, a fim de facilitar a produção quase contínua de vídeos. Ao gravar vídeos, o comprimento mínimo recomendado é de aproximadamente 240 segundos com qualquer composto de teste que está sendo adicionado à marca dos 60 segundos. Isso garante que o investigador tem uma janela 60 seg para conseguir frequência cardíaca linha de base e, em seguida, uma outra janela 60 seg para conseguir pós-tratamento taxa cardíaca de 120 segdepois do tratamento. </li></ol>

<ol>
	<li>Klowden, 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=Circulatory+Systems.">Circulatory Systems.</a> Physiological Systems in Insects, 3rd Edition. , 365-413 (2013).</li><li>League, G. P., Onuh, O. C., Hillyer, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+structural+and+functional+analysis+of+the+larval+and+adult+dorsal+vessel+and+its+role+in+hemolymph+circulation+in+the+mosquito+Anopheles+gambiae.">Comparative structural and functional analysis of the larval and adult dorsal vessel and its role in hemolymph circulation in the mosquito Anopheles gambiae.</a> J Exp Biol. 218 (Pt 3), 370-380 (2015).</li><li>Wasserthal, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oscillating+Hemolymph+Circulation+in+the+Butterfly+Papilio-Machaon+L+Revealed+by+Contact+Thermography+and+Photocell+Measurements.">Oscillating Hemolymph Circulation in the Butterfly Papilio-Machaon L Revealed by Contact Thermography and Photocell Measurements.</a> J Comp Physiol. 139 (2), 145-163 (1980).</li><li>Wasserthal, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interaction+of+circulation+and+tracheal+ventilation+in+holometabolous+insects.">Interaction of circulation and tracheal ventilation in holometabolous insects.</a> Adv Insect Physiol. 26, 297-351 (1996).</li><li>Schwab, E. R., Chilson, R. A., Eddleman, 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=Heartbeat+Rate+Modulation+Mediated+by+the+Ventral+Nerve+Cord+in+the+Honey-Bee,+Apis-Mellifera.">Heartbeat Rate Modulation Mediated by the Ventral Nerve Cord in the Honey-Bee, Apis-Mellifera.</a> J Comp Physiol B-Biochem Syst Environ Physiol. 161 (6), 602-610 (1991).</li><li>Kaiser, W., Weber, T., Otto, D., Miroschnikow, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen+supply+of+the+heart+and+electrocardiogram+potentials+with+reversed+polarity+in+sleeping+and+resting+honey+bees.">Oxygen supply of the heart and electrocardiogram potentials with reversed polarity in sleeping and resting honey bees.</a> Apidologie. 45 (1), 73-87 (2014).</li><li>Papaefthimiou, C., Theophilidis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Octopamine--a+single+modulator+with+double+action+on+the+heart+of+two+insect+species+(Apis+mellifera+macedonica+and+Bactrocera+oleae):+Acceleration+vs.+inhibition.">Octopamine--a single modulator with double action on the heart of two insect species (Apis mellifera macedonica and Bactrocera oleae): Acceleration vs. inhibition.</a> J Insect Physiol. 57 (2), 316-325 (2011).</li><li>Castro, C. A., Hogan, J. B., Benson, K. A., Shehata, C. W., Landauer, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral-Effects+of+Vehicles+-+Dmso,+Ethanol,+Tween-20,+Tween-80,+and+Emulphor-620.">Behavioral-Effects of Vehicles - Dmso, Ethanol, Tween-20, Tween-80, and Emulphor-620.</a> Pharmacol Biochem Behav. 50 (4), 521-526 (1995).</li><li>Papaefthimiou, C., Papachristoforou, A., Theophilidis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biphasic+responses+of+the+honeybee+heart+to+nanomolar+concentrations+of+amitraz.">Biphasic responses of the honeybee heart to nanomolar concentrations of amitraz.</a> Pestic Biochem Phys. 107 (1), 132-137 (2013).</li><li>Roeder, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Octopamine+in+invertebrates.">Octopamine in invertebrates.</a> Prog Neurobiol. 59 (5), 533-561 (1999).</li><li>Johnson, E., Ringo, J., Dowse, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+Drosophila+heartbeat+by+neurotransmitters.">Modulation of Drosophila heartbeat by neurotransmitters.</a> J Comp Physiol B. 167 (2), 89-97 (1997).</li></ol>

The authors have nothing to disclose.

The protocol presented here provides a simple and effective approach to testing pharmacological compounds for their effects on honey bee heart rate. As observed in prior experiments that either transect the ventral nerve cord of a living insect5 or dissect out the ventral nerve cord when exposing the dorsal vessel7, the loss of central nervous system regulation results in a stable, low frequency heartbeat. The low frequency of beats allows the investigator to visually assess heart rate without havin...

O objetivo geral desta metodologia é permitir que o investigador rapidamente e facilmente observar e quantificar o efeito que um agente farmacológico tem sobre o ritmo cardíaco das abelhas. As abelhas, como outros insectos, tem um sistema circulatório aberto que divulga hemolinfa, o equivalente de insectos de sangue, através da cavidade corporal, conhecido como o hemocelo. A circulação de hemolinfa é essencial para o transporte de nutrientes, factores do sistema imunológico, produtos de resíduos, bem neuro-hormonas e outras moléculas de sinalização 1. A circulação é facilitada pelo vaso dorsal, que se estende ao longo da linha média dorsal de insecto, bem como órgãos acessórios pulsáteis. O vaso dorsal é dividida em duas partes funcionalmente distintas, designou o coração no abdômen e na aorta no tórax e na cabeça. contrações propagadas na hemolinfa bomba do coração em direção ao tórax e cabeça, enquanto órgãos pulsátil acessórias garantir o fluxo de hemolinfa para as extremidades. <pclasse = &quot;jove_content&quot;&gt; função cardíaca insecto pode ser observada usando uma variedade de métodos, dependendo do tamanho, fisiologia fase, ou de vida do insecto. Uma abordagem comum para a observação da frequência cardíaca em larvas ou insetos menores é o uso de imagens intravital 2. Este método é menos útil em abelhas adultas, no entanto, uma vez que pode ser difícil de visualizar claramente o vaso dorsal através da parede abdominal. Uma abordagem estabelecida para gravar a frequência cardíaca em uma variedade de insectos, incluindo abelhas, é o uso de termografia de contacto, que utiliza termistores aplicado ao exterior do insecto para detectar pulsações cardíacas 3,4. A frequência cardíaca em abelhas adultas também foi gravada usando uma técnica eletrofisiológica para medir um sinal de 4,5 impedância elétrica. Esta técnica requer a inserção dos eléctrodos no animal ao lado do coração e a utilização de um conversor de impedância para gravar pulsações 4. Da mesma forma, electrocardiogramas foram usadas para detect sinais elétricos produzidos pelo coração e combinados com gravação de vídeo da abelha para observar mudanças na atividade cardíaca 6. Uma vantagem distinta para estas abordagens é que a frequência cardíaca é avaliada em, uma abelha viva intacta, em vez de em um espécime dissecado, que contribui para garantir a disponibilidade de toda a gama de respostas fisiológicas do sujeito. Os desafios destas abordagens incluem contabilidade para imobilização ou anesthetization do assunto, a necessidade de limitar as variáveis ​​externas e estímulos que podem alterar o ritmo cardíaco, bem como para determinar um método de entrega adequado ao testar agentes farmacológicos. Outra abordagem que tem sido utilizado para estudar a atividade cardíaca abelha é dissecar parcialmente o inseto, a fim de expor o coração, em seguida medir contrações vaso dorsal, utilizando uma força de deslocamento transdutor 7. Neste protocolo, o coração é continuamente banhado com soro fisiológico em execução e co testempounds pode ser dissolvido nesta solução para aplicação sobre o assunto 7. Uma diferença significativa entre este método e os anteriormente descritos é que o cordão nervoso ventral é removido, eliminando o papel que o sistema nervoso central tem mostrado desempenhar na modulação da frequência cardíaca 5. O resultado é que a pulsação da linha de base, o qual geralmente é bastante errático, estabiliza a uma frequência muito mais baixa e a amplitude do que o tipicamente observado em um insecto vivo 5,7. O que todos estes métodos têm em comum é que eles exigem equipamento altamente especializado e, muitas vezes caros, além de um certo nível de perícia, a fim de ser conduzido. Talvez a maior desvantagem é que nenhuma destas abordagens são particularmente bem adequado para experiências que envolvem o teste de um grande número de sujeitos, tais como o rastreio de uma biblioteca de compostos potencialmente cardiomodulatory. A maior força da abordagem aqui descritaé a sua simplicidade. O protocolo é relativamente fácil de dominar, a instalação requer pouco espaço, e apenas uma entrada financeiro mínimo é necessário. O método requer pouco mais de cerca de abelhas, alguns instrumentos cirúrgicos, uma solução isotónica, e quer um microscópio digital ou um microscópio tradicional com uma câmara digital. As abelhas são dissecados para visualizar o vaso dorsal e vídeos digitais são usados ​​para gravar a frequência cardíaca antes e após o tratamento com agentes farmacológicos. Embora a gravação de vídeo não é realmente necessário observar alterações do ritmo cardíaco, ele irá aumentar o rendimento muito (ou seja, o número de indivíduos que podem ser processados em um determinado período de tempo). O investigador pode maximizar a eficiência através da gravação de um grande número de vídeos de uma só vez e depois marcando esses vídeos em um momento mais conveniente. Outra vantagem dessa abordagem é que os vídeos permitem que o investigador de começar de novo, deve o processo de pontuação ser interrompido, e torná-lo mais fácil para o viewer ser cegos para o tratamento, a fim de reduzir o desvio.

<table border="0" cellpadding="0" cellspacing="0" width="834">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:200px;">Dino-Lite Edge digital USB microscope</td>
			<td style="width:111px;">Dino-Lite</td>
			<td style="width:119px;">AM4815ZT</td>
			<td style="width:405px;">Any digital microscope or similar setup will suffice</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Microscope stand</td>
			<td style="width:111px;">Dino-Lite</td>
			<td style="width:119px;">RK-10</td>
			<td>Any stand appropriate for the digital microscope</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Laptop or PC</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td>Necessary for digital microscope</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:200px;">Microdissection scissors (Vannas, 8cm, Straight, 5mm Blades)</td>
			<td style="width:111px;">World Precision Instruments</td>
			<td style="width:119px;">14003</td>
			<td>Any similar scissors suitable for microdissection will suffice</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:200px;">Microdissecting Forceps, 10.2cm, Angled (2 pair)</td>
			<td style="width:111px;">World Precision Instruments</td>
			<td style="width:119px;">504482</td>
			<td>Any similar forceps suitable for microdissection will suffice</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:200px;">Ringers solution 1/4 strength tablets&#160;</td>
			<td style="width:111px;">Sigma-Aldrich</td>
			<td style="width:119px;">96724-100TAB</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Dissecting tray</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td>Any surface suitable for microdissection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Single channel 10 &#181;l pipette</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td>Any device capable of accurately delivering 10 &#181;l volume</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Pipette tips</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:200px;">Small beaker or container of water</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td>Used to rinse instruments between subjects</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Hand tally counter</td>
			<td style="width:111px;">Office Depot</td>
			<td style="width:119px;">295033</td>
			<td>Any similar product will suffice</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Timer</td>
			<td style="width:111px;">Office Depot</td>
			<td style="width:119px;">644219</td>
			<td>Any similar product will suffice</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:200px;">Deionized water</td>
			<td style="width:111px;"></td>
			<td style="width:119px;"></td>
			<td>Preparation of Ringers solution and rinsing instruments</td>
		</tr>
	</tbody>
</table>

dissection and observation of honey bee dorsal vessel for studies of cardiac function

The European honey bee, Apis mellifera L., is a valuable agricultural and commercial resource noted for producing honey and providing crop pollination services, as well as an important model social insect used to study memory and learning, aging, and more. Here we describe a detailed protocol for the dissection of the dorsal abdominal wall of a bee in order to visualize its dorsal vessel, which serves the role of the heart in the insect. A successful dissection will expose a functional heart that, under the proper conditions, can maintain a steady heartbeat for an extended period of time. This allows the investigator to manipulate heart rate through the application of cardiomodulatory compounds to the dorsal vessel. By using either a digital microscope or a microscope equipped with a digital camera, the investigator can make video recordings of the dorsal vessel before and after treatment with test compounds. The videos can then be scored at a time convenient to the user in order to determine changes in heart rate, as well as changes in the pattern of heartbeats, following treatment. The advantages of this protocol are that it is relatively inexpensive to set up, easy to learn, requires little space or equipment, and takes very little time to conduct.

Uma vez que muitos dos compostos farmacologicamente activos que podem ser testados utilizando este protocolo não são solúveis em água, é necessário ter um solvente fiável que permita que os compostos de teste a ser entregue através da solução isotónica utilizados para banhar o vaso dorsal. Dimetil sulfóxido (DMSO) é um solvente que é comumente utilizado como um veículo para a entrega de drogas e outros compostos experimentais em animais 8, e que tem sido usado c...

Watch this Scientific Journal Video about Dissection and Observation of Honey Bee Dorsal Vessel for Studies of Cardiac Function at JoVE.com

Dissection and Observation of Honey Bee Dorsal Vessel for Studies of Cardiac Function

The abdominal dorsal vessel of the honey bee and other insects serves as the functional equivalent of the mammalian heart and plays an important role in nutrient transport, waste removal, immune function, and more. Here we describe a protocol for the visualization and pharmacological manipulation of bee heart rate.

Dissecção e Observação de Honey Bee Dorsal navio de Estudos da função cardíaca

The European honey bee, Apis mellifera L., is a valuable agricultural and commercial resource noted for producing honey and providing crop pollination ...

dissection-observation-honey-bee-dorsal-vessel-for-studies-cardiac

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10.8K visualizações.  Virginia Tech. The abdominal dorsal vessel of the honey bee and other insects serves as the functional equivalent of the mammalian heart and plays an important role in nutrient transport, waste removal, immune function, and more. Here we describe a protocol for the visualization and pharmacological manipulation of bee heart rate.

Vídeo: Dissection and Observation of Honey Bee Dorsal Vessel for Studies of Cardiac Function

In vivo Ca2+- Imaging of Mushroom Body Neurons During Olfactory Learning in the Honey Bee

The in vivo and semi-in vivo preparation for Calcium imaging has been developed in our lab by Joerges, K&uuml;ttner and Galizia over ten years ago, to measure odor evoked activity in the antennal lobe1. From then on, it has been continuously refined and applied to different neuropiles in the bee brain. Here, we describe the preparation currently used in the lab to measure activity in mushroom body neurons using a dextran coupled calcium-sensitive dye (Fura-2). We retrogradely stain mushroom body neurons by injecting dye into their axons or soma region. We focus on reducing the invasiveness, to achieve a preparation in which it is still possible to train the bee using PER conditioning. We are able to monitor and quantify the behavioral response by recording electro-myograms from the muscle which controls the PER (M17)2.
After the physiological experiment the imaged structures are investigated in greater detail using confocal scanning microscopy to address the identity of the neurons.

In vivo Ca2+- Imaging of Mushroom Body Neurons During Olfactory Learning in the Honey Bee

Bees can be conditioned in an appetitive olfactory learning paradigm (PER-conditioning). Using odors as stimuli, we established a method in which behavior is recorded while simultaneously Calcium Imaging is used to measure odor evoked activity in mushroom body neurons in vivo.

In vivo Ca 2 + - Imagem de Neurônios Corpo Mushroom durante o aprendizado olfativo no Honey Bee

The in vivo and semi-in vivo preparation for Calcium imaging has been developed in our lab by Joerges, K&uuml;ttner and Galizia over ten years ago, to ...

Biologia

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae. For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. The larval heart preparation provides an additional model besides the Drosophila skeletal NMJ to investigate the role of intracellular calcium regulation on cellular function. Learning more about the underlying ionic currents that shape the action potentials in myocytes in various species, one can hope to get a handle on the known ionic dysfunctions associated to specific genes responsible for various diseases in mammals.

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various ways to monitor heart function in the larva of Drosophila for assessing questions dealing with the function of gap junctions, ion channel mutations, modulation of pacemaker activity and pharmacological studies.

Função de monitorização cardíaca em larval Drosophila melanogaster Para estudos fisiológicos

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained  and  ...

Mutagenesis and Functional Analysis of Ion Channels Heterologously Expressed in Mammalian Cells

We will demonstrate how to study the functional effects of introducing a point mutation in an ion channel. We study G protein-gated inwardly rectifying potassium (referred to as GIRK) channels, which are important for regulating the excitability of neurons. There are four different mammalian GIRK channel subunits (GIRK1-GIRK4) - we focus on GIRK2 because it forms a homotetramer. Stimulation of different types of G protein-coupled receptors (GPCRs), such as the muscarinic receptor (M2R), leads to activation of GIRK channels. Alcohol also directly activates GIRK channels. We will show how to mutate one amino acid by specifically changing one or more nucleotides in the cDNA for the GIRK channel. This mutated cDNA sequence will be amplified in bacteria, purified, and the presence of the point mutation will be confirmed by DNA sequencing. The cDNAs for the mutated and wild-type GIRK channels will be transfected into human embryonic kidney HEK293T cells cultured in vitro. Lastly, whole-cell patch-clamp electrophysiology will be used to study the macroscopic potassium currents through the ectopically expressed wild-type or mutated GIRK channels. In this experiment, we will examine the effect of a L257W mutation in GIRK2 channels on M2R-dependent and alcohol-dependent activation.

We will demonstrate how to study the effect of a single point mutation on the function of an ion channel.

Mutagênese e Análise Funcional de canais iônicos Heterologously Expresso em células de mamíferos

We will demonstrate how to study the functional effects of introducing a point mutation in an ion channel. We study G protein-gated inwardly rectifying ...

Basic Caenorhabditis elegans Methods: Synchronization and Observation

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3.
C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. 
An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. 
Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them.

Basic Caenorhabditis elegans Methods: Synchronization and Observation

The easiness of maintaining and propagating the nematode C. elegans make it a nice model organism to work with. The possibility of synchronizing worms allows the work with a significant amount of subjects at the same developmental stage, what facilitates the study of one particular process in many animals.

Básico<em&gt; Caenorhabditis elegans</em&gt; Métodos: Sincronização e observação

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has ...

Intravital Microscopy of the Microcirculation in the Mouse Cremaster Muscle for the Analysis of Peripheral Stem Cell Migration

In the era of intravascular cell application protocols in the context of regenerative cell therapy, the underlying mechanisms of stem cell migration to nonmarrow tissue have not been completely clarified. We describe here the technique of intravital microscopy applied to the mouse cremaster microcirculation for analysis of peripheral bone marrow stem cell migration in vivo. Intravital microscopy of the M. cremaster has been previously introduced in the field of inflammatory research for direct observation of leucocyte interaction with the vascular endothelium. Since sufficient peripheral stem and progenitor cell migration includes similar initial steps of rolling along and firm adhesion at the endothelial lining it is conceivable to apply the M. cremaster model for the observation and quantification of the interaction of intravasculary administered stem cells with the endothelium. As various chemical components can be selectively applied to the target tissue by simple superfusion techniques, it is possible to establish essential microenvironmental preconditions, for initial stem cell recruitment to take place in a living organism outside the bone marrow.

Intravital microscopy of the mouse M. cremaster microcirculation offers a unique and well-standardized in vivo model for the analysis of peripheral bone marrow stem cell migration.

Microscopia intravital da Microcirculação no músculo Rato Cremaster de Análise de Migração Stem Peripheral celular

In the era of intravascular cell application protocols in the context of regenerative cell therapy, the underlying mechanisms of stem cell migration to ...

Obtaining Specimens with Slowed, Accelerated and Reversed Aging in the Honey Bee Model

Societies of highly social animals feature vast lifespan differences between closely related individuals. Among social insects, the honey bee is the best established model to study how plasticity in lifespan and aging is explained by social factors.
The worker caste of honey bees includes nurse bees, which tend the brood, and forager bees, which collect nectar and pollen. Previous work has shown that brain functions and flight performance senesce more rapidly in foragers than in nurses. However, brain functions can recover, when foragers revert back to nursing tasks. Such patterns of accelerated and reversed functional senescence are linked to changed metabolic resource levels, to alterations in protein abundance and to immune function. Vitellogenin, a yolk protein with adapted functions in hormonal control and cellular defense, may serve as a major regulatory element in a network that controls the different aging dynamics in workers.
Here we describe how the emergence of nurses and foragers can be monitored, and manipulated, including the reversal from typically short-lived foragers into longer-lived nurses. Our representative results show how individuals with similar chronological age differentiate into foragers and nurse bees under experimental conditions. We exemplify how behavioral reversal from foragers back to nurses can be validated. Last, we show how different cellular senescence can be assessed by measuring the accumulation of lipofuscin, a universal biomarker of senescence.
For studying mechanisms that may link social influences and aging plasticity, this protocol provides a standardized tool set to acquire relevant sample material, and to improve data comparability among future studies.

In honey bee workers, aging depends on social behaviors rather than on chronological age. Here we show how worker-types with very different aging patterns can be obtained and analyzed for cellular senescence.

Obtenção de amostras com retardado, acelerado e invertida Envelhecimento no Modelo Bee Mel

Societies of highly social animals feature vast lifespan differences between closely related individuals. Among social insects, the honey bee is the best ...

Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of transporters. The phosphorylation and nucleotide dependent chloride channel activity of CFTR has been frequently studied in whole cell systems and as single channels in excised membrane patches. Many Cystic Fibrosis-causing mutations have been shown to alter this activity. While a small number of purification protocols have been published, a fast reconstitution method that retains channel activity and a suitable method for studying population channel activity in a purified system have been lacking. Here rapid methods are described for purification and functional reconstitution of the full-length CFTR protein into proteoliposomes of defined lipid composition that retains activity as a regulated halide channel. This reconstitution method together with a novel flux-based assay of channel activity is a suitable system for studying the population channel properties of wild type CFTR and the disease-causing mutants F508del- and G551D-CFTR. Specifically, the method has utility in studying the direct effects of phosphorylation, nucleotides and small molecules such as potentiators and inhibitors on CFTR channel activity. The methods are also amenable to the study of other membrane channels/transporters for anionic substrates.

Described here is a rapid and effective procedure for functional reconstitution of purified wild-type and mutant CFTR protein that preserves activity for this chloride channel, which is defective in Cystic Fibrosis. Iodide efflux from reconstituted proteoliposomes mediated by CFTR allows studies of channel activity and the effects of small molecules.

Reconstituição funcional e atividade do canal Medidas de purificada tipo selvagem e mutante CFTR Protein

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of ...

Methods for Comparing Nutrients in Beebread Made by Africanized and European Honey Bees and the Effects on Hemolymph Protein Titers

Honey bees obtain nutrients from pollen they collect and store in the hive as beebread. We developed methods to control the pollen source that bees collect and convert to beebread by placing colonies in a specially constructed enclosed flight area. Methods were developed to analyze the protein and amino acid composition of the pollen and beebread. We also describe how consumption of the beebread was measured and methods used to determine adult worker bee hemolymph protein titers after feeding on beebread for 4, 7 and 11 days after emergence. Methods were applied to determine if genotype affects the conversion of pollen to beebread and the rate that bees consume and acquire protein from it. Two subspecies (European and Africanized honey bees; EHB and AHB respectively) were provided with the same pollen source. Based on the developed methods, beebread made by both subspecies had lower protein concentrations and pH values than the pollen. In general, amino acid concentrations in beebread made by either EHB or AHB were similar and occurred at higher levels in beebread than in pollen. Both AHB and EHB consumed significantly more of the beebread made by AHB than by EHB. Though EHB and AHB consumed similar amounts of each type of beebread, hemolymph protein concentrations in AHB were higher than in EHB. Differences in protein acquisition between AHB and EHB might reflect environmental adaptations related to the geographic region where each subspecies evolved. These differences could contribute to the successful establishment of AHB populations in the New World because of the effects on brood rearing and colony growth.

Here are methods to quantify nutrients in pollen before and after its conversion to beebread by two subspecies of honeybees. We describe techniques to measure beebread consumption and resulting protein titers in both subspecies.

Métodos para comparar Nutrientes na beebread Feito por africanizadas e mel europeu abelhas e os efeitos sobre Títulos Hemolinfa Proteína

Honey bees obtain nutrients from pollen they collect and store in the hive as beebread. We developed methods to control the pollen source that bees ...

Analysis of the Gap Junction-dependent Transfer of miRNA with 3D-FRAP Microscopy

Small antisense RNAs, like miRNA and siRNA, play an important role in cellular physiology and pathology and, moreover, can be used as therapeutic agents in the treatment of several diseases. The development of new, innovative strategies for miRNA/siRNA therapy is based on an extensive knowledge of the underlying mechanisms. Recent data suggest that small RNAs are exchanged between cells in a gap junction-dependent manner, thereby inducing gene regulatory effects in the recipient cell. Molecular biological techniques and flow cytometric analysis are commonly used to study the intercellular exchange of miRNA. However, these methods do not provide high temporal resolution, which is necessary when studying the gap junctional flux of molecules. Therefore, to investigate the impact of miRNA/siRNA as intercellular signaling molecules, novel tools are needed that will allow for the analysis of these small RNAs at the cellular level. The present protocol describes the application of three-dimensional fluorescence recovery after photobleaching (3D-FRAP) microscopy to elucidating the gap junction-dependent exchange of miRNA molecules between cardiac cells. Importantly, this straightforward and non-invasive live-cell imaging approach allows for the visualization and quantification of the gap junctional shuttling of fluorescently labeled small RNAs in real time, with high spatio-temporal resolution. The data obtained by 3D-FRAP confirm a novel pathway of intercellular gene regulation, where small RNAs act as signaling molecules within the intercellular network.

Here, we describe the application of three-dimensional fluorescence recovery after photobleaching (3D-FRAP) for the analysis of the gap junction-dependent shuttling of miRNA. In contrast to commonly applied methods, 3D-FRAP allows for the quantification of the intercellular transfer of small RNAs in real time, with high spatio-temporal resolution.

Análise do Gap Junction-dependente Transferência de miARN com 3D-FRAP Microscopia

Small antisense RNAs, like miRNA and siRNA, play an important role in cellular physiology and pathology and, moreover, can be used as therapeutic agents ...

Monitoring Colony-level Effects of Sublethal Pesticide Exposure on Honey Bees

The effects of sublethal pesticide exposure to honey bee colonies may be significant but difficult to detect in the field using standard visual assessment methods. Here we describe methods to measure the quantities of adult bees, brood, and food resources by weighing hives and hive parts, by photographing frames, and by installing hives on scales and with internal sensors. Data from these periodic evaluations are then combined with running average and daily detrended data on hive weight and internal hive temperature. The resulting datasets have been used to detect colony-level effects of imidacloprid applied in a sugar syrup as low as 5 parts per billion. The methods are objective, require little training, and provide permanent records in the form of sensor output and photographs.

Sublethal doses of pesticides may affect colonies in ways that are difficult to detect using only periodic or visual methods. Methods to measure total adult bee mass, brood, and food resources by weighing hives and hive parts, photographing frames, and installing sensors, are provided. Data analysis is also addressed.

Monitoramento de nível de colônia os efeitos da exposição de pesticidas subletais em mel de abelhas

The effects of sublethal pesticide exposure to honey bee colonies may be significant but difficult to detect in the field using standard visual assessment ...

Dissecção e Observação de Honey Bee Dorsal navio de Estudos da função cardíaca

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In vivo Ca ^{2 +} - Imagem de Neurônios Corpo Mushroom durante o aprendizado olfativo no Honey Bee