The following description is not specific for one motoneuron. It can be used with any neuron. In this example, we use the flight motoneuron 5 (MN5) that innervates the two dorsalmost fibers of the dorsolongitudinal wing depressor muscle (DLM). To identify and visualize MN5 we use the UAS/GAL4 system to express GFP in the flight motoneurons (and few other neurons).
1. Dissection of Adult Drosophila to Access the Dorsal Part of the Ventral Nerve Cord (VNC)
<ol>
 <li>Dissect an adult <...

<ol>
	<li>Papazian, D. M., Schwarz, T. L., Tempel, B. L., Jan, Y. N., Jan, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning+of+genomic+and+complementary+DNA+from+Shaker,+a+putative+potassium+channel+gene+from+Drosophila.">Cloning of genomic and complementary DNA from Shaker, a putative potassium channel gene from Drosophila.</a> Science. 237, 749-753 (1987).</li><li>Tempel, B. L., Papazian, D. M., Schwarz, T. L., Jan, Y. N., Jan, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequence+of+a+probable+potassium+channel+component+encoded+at+Shaker+locus+of+Drosophila.">Sequence of a probable potassium channel component encoded at Shaker locus of Drosophila.</a> Science. 237, 770-775 (1987).</li><li>Gu, H., O'Dowd, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+Cell+Recordings+from+Brain+of+Adult+Drosophila.">Whole Cell Recordings from Brain of Adult Drosophila.</a> J. Vis. Exp. (6), e248 (2007).</li><li>Gu, H., Jiang, S. A., Campusano, J. M., Iniguez, J., Su, H., Hoang, A. A., Lavian, M., Sun, X., O'Dowd, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cav2-type+calcium+channels+encoded+by+cac+regulate+AP-independent+neurotransmitter+release+at+cholinergic+synapses+in+adult+Drosophila+brain.">Cav2-type calcium channels encoded by cac regulate AP-independent neurotransmitter release at cholinergic synapses in adult Drosophila brain.</a> J. Neurophysiol. 101, 42-53 (2009).</li><li>Baines, R. A., Bate, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+development+of+central+neurons+in+the+Drosophila+embryo.">Electrophysiological development of central neurons in the Drosophila embryo.</a> J. Neurosci. 18, 4673-4683 (1998).</li><li>Lin, W. H., Wright, D. E., Muraro, N. I., Baines, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternative+splicing+in+the+voltage-gated+sodium+channel+DmNav+regulates+activation,+inactivation,+and+persistent+current.">Alternative splicing in the voltage-gated sodium channel DmNav regulates activation, inactivation, and persistent current.</a> J. Neurophysiol. 102, 1994-2006 (2009).</li><li>Worrell, J. W., Levine, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+voltage-dependent+Ca2++currents+in+identified+Drosophila+motoneurons+in+situ.">Characterization of voltage-dependent Ca2+ currents in identified Drosophila motoneurons in situ.</a> J. Neurophysiol. 100, 868-878 (2008).</li><li>Srinivasan, S., Lance, K., Levine, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Segmental+differences+in+firing+properties+and+potassium+currents+in+Drosophila+larval+motoneurons.">Segmental differences in firing properties and potassium currents in Drosophila larval motoneurons.</a> J. Neurophysiol. , (2011).</li><li>Choi, J. C., Park, D., Griffith, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+and+morphological+characterization+of+identified+motor+neurons+in+the+Drosophila+third+instar+larva+central+nervous+system.">Electrophysiological and morphological characterization of identified motor neurons in the Drosophila third instar larva central nervous system.</a> J. Neurophysiol. 91, 2353-2365 (2004).</li><li>Pulver, S. R., Griffith, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spike+integration+and+cellular+memory+in+a+rhythmic+network+from+Na+/K++pump+current+dynamics.">Spike integration and cellular memory in a rhythmic network from Na+/K+ pump current dynamics.</a> Nat. Neurosci. 13, 53-59 (2010).</li><li>Fayyazuddin, A., Zaheer, M. A., Hiesinger, P. R., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nicotinic+acetylcholine+receptor+Dalpha7+is+required+for+an+escape+behavior+in+Drosophila.">The nicotinic acetylcholine receptor Dalpha7 is required for an escape behavior in Drosophila.</a> PLoS Biol. 4, e63 (2006).</li><li>Duch, C., Vonhoff, F., Ryglewski, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dendrite+elongation+and+dendritic+branching+are+affected+separately+by+different+forms+of+intrinsic+motoneuron+excitability.">Dendrite elongation and dendritic branching are affected separately by different forms of intrinsic motoneuron excitability.</a> J. Neurophysiol. 100, 2525-2536 (2008).</li><li>Ryglewski, S., Duch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shaker+and+Shal+mediate+transient+calcium-independent+potassium+current+in+a+Drosophila+flight+motoneuron.">Shaker and Shal mediate transient calcium-independent potassium current in a Drosophila flight motoneuron.</a> J. Neurophysiol. 102, 3673-3688 (2009).</li><li>Ryglewski, S., Lance, K., Levine, R. B., Duch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cav2+Channels+Mediate+LVA+and+HVA+Calcium+Currents+in+Drosophila+Motoneurons.">Cav2 Channels Mediate LVA and HVA Calcium Currents in Drosophila Motoneurons.</a> J. Physiol. , (2011).</li><li>Ikeda, K., Koenig, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+identification+of+the+motor+neurons+innervating+the+dorsal+longitudinal+flight+muscle+of+Drosophila+melanogaster.">Morphological identification of the motor neurons innervating the dorsal longitudinal flight muscle of Drosophila melanogaster.</a> J. Comp. Neurol. 1273, 436-444 (1988).</li><li>Boerner, J., Godenschwege, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+Mount+Preparation+of+the+Adult+Drosophila+Ventral+Nerve+Cord+for+Giant+Fiber+Dye+Injection.">Whole Mount Preparation of the Adult Drosophila Ventral Nerve Cord for Giant Fiber Dye Injection.</a> J. Vis. Exp. (52), e3080 (2011).</li></ol>

When visualizing the cells with fluorescent proteins like GFP, it is important to not over-expose the preparation to too much light. This may result in photo damage. We use 100W HBO short arc mercury bulbs for illumination, and we also use neutral density (ND) of 0.8 (Chroma ND filters 0.3 and 0.5). To be able to judge on the quality of the cleaning good visibility is crucial. Therefore, ND filters may be removed for short periods of about 20 s for multiple times.
When applying some positive ...

<table border="1">
 <tbody>
 <tr>
 <td>Agent/item</td>
 <td>Company</td>
 <td>Catalog number</td>
 </tr>
 <tr>
 <td>Protease type XIV</td>
 <td>Sigma Aldrich USA</td>
 <td>P5147</td>
 </tr>
 <tr>
 <td>Microfil flexible injection needle</td>
 <td>World Precision Instruments USA</td>
 <td>MF28G-5</td>
 </tr>
 <tr>
 <td>Borosilicate Glass Capillaries, o.d. 1.5 mm, i.d. 1.0 mm, no filament</td>
 <td>World Precision Instruments USA</td>
 <td>PG52151-4</td>
 </tr>
 <tr>
 <td>DiI</td>
 <td>Invitrogen USA</td>
 <td>D3899</td>
 </tr>
 <tr>
 <td>Sylgard Elastomer Kit 184 (Dow Corning)</td>
 <td><a href="http://www.ellsworth.com" target="_blank">www.ellsworth.com</a></td>
 <td>184 SIL ELAST KIT </td>
 </tr>
 <tr>
 <td>ND filter set (unmounted)</td>
 <td>Chroma</td>
 <td>22000b series</td>
 </tr>
 <tr>
 <td>Electrode holder 1-HL-U</td>
 <td>Molecular Devices</td>
 <td>1-HL-U</td>
 </tr>
 </tbody>
</table>

preparation of drosophila central neurons for in situ patch clamping

Short generation times and facile genetic techniques make the fruit fly Drosophila melanogaster an excellent genetic model in fundamental neuroscience research. Ion channels are the basis of all behavior since they mediate neuronal excitability. The first voltage gated ion channel cloned was the Drosophila voltage gated potassium channel Shaker1,2. Toward understanding the role of ion channels and membrane excitability for nervous system function it is useful to combine powerful genetic tools available in Drosophila with in situ patch clamp recordings. For many years such recordings have been hampered by the small size of the Drosophila CNS. Furthermore, a robust sheath made of glia and collagen constituted obstacles for patch pipette access to central neurons. Removal of this sheath is a necessary precondition for patch clamp recordings from any neuron in the adult Drosophila CNS. In recent years scientists have been able to conduct in situ patch clamp recordings from neurons in the adult brain3,4 and ventral nerve cord of embryonic5,6, larval7,8,9,10, and adult Drosophila11,12,13,14. A stable giga-seal is the main precondition for a good patch and depends on clean contact of the patch pipette with the cell membrane to avoid leak currents. Therefore, for whole cell in situ patch clamp recordings from adult Drosophila neurons must be cleaned thoroughly. In the first step, the ganglionic sheath has to be treated enzymatically and mechanically removed to make the target cells accessible. In the second step, the cell membrane has to be polished so that no layer of glia, collagen or other material may disturb giga-seal formation. This article describes how to prepare an identified central neuron in the Drosophila ventral nerve cord, the flight motoneuron 5 (MN515), for somatic whole cell patch clamp recordings. Identification and visibility of the neuron is achieved by targeted expression of GFP in MN5. We do not aim to explain the patch clamp technique itself.

Watch this Scientific Journal Video about Preparation of Drosophila Central Neurons for in situ Patch Clamping at JoVE.com

Preparation of Drosophila Central Neurons for in situ Patch Clamping

In situ patch clamp recordings are used for electrophysiological characterization of neurons in intact circuitry. In the Drosophila genetic model patch clamping is difficult because the CNS is small and surrounded by a robust sheath. This article describes the procedure to remove the sheath and clean neurons for subsequent patch clamp recordings.

Preparation of Drosophila Central Neurons for in situ Patch Clamping

Short generation times and facile genetic techniques make the fruit fly Drosophila melanogaster an excellent genetic model in fundamental neuroscience ...

preparation-of-drosophila-central-neurons-for-in-situ-patch-clamping

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JoVE Journal

Neuroscience

13.9K Views.  Arizona State University. In situ di patch clamp registrazioni sono utilizzate per la caratterizzazione elettrofisiologica dei neuroni nel circuito intatto. Nel modello Drosophila genetico cerotto bloccaggio è difficile perché il CNS è piccolo e circondato da una guaina robusta. Questo articolo descrive la procedura per rimuovere i neuroni guaina e pulite per le registrazioni successive patch clamp.