The authors thank Mick Swann, Chris Askham and Martin Gautrey for their important contributions in designing and building many electrical and mechanical components of the rigs. MJ's current research is supported by the Biotechnology and Biological Sciences Research Council (BBSRC Grant: BB/M009564/1), the State Key Laboratory of Cognitive Neuroscience and Learning open research fund (China), High-End Foreign Expert Grant (China), Jane and Aatos Erkko Foundation Fellowship (Finland), and the Leverhulme Trust grant (RPG-2012-567).

The authors have nothing to disclose

We have presented the basic key steps of how to use sharp conventional microelectrodes to record intracellular responses of R1-R6 photoreceptors and LMCs in intact fly eyes. This method has been optimized, together with bespoke hardware and software tools, over the last 18 years to provide high-quality long-lasting recordings to answer a wide range of experimental questions. By investing time and resources to construct robust and precise experimental set-ups, and to produce microelectrodes with favorable electrical properties, high-quality recordings can become the norm in any laboratory working on Drosophila visual neurophysiology. Whilst well-designed recording and light stimulation systems are important for swift execution of different experimental paradigms, there are three procedural steps that are even more critical to achieving successful recordings: (i) to make the fly preparation with minimal eye damage, (ii) to pull microelectrodes with the right electrical properties, and (iii) to drive the recording electrode into the eye without breaking its tip. Ultimately, to record meaningful data, the investigator has to understand the physical basis of electrophysiology and how to fabricate suitable microelectrodes for the targeted cell-types.
Therefore, the limitations of this technique are primarily set by the patience, experience and technical ability of the investigator. Because this technique can take a long time to master for small Drosophila cells, it is advisable for trainee electrophysiologists to first practice with larger insect eyes, such as the blowfly36 or locust35, using the same rig. Once performing high-quality intracellular recordings from the larger photoreceptors and interneurons becomes routine, it is time to move on to the Drosophila eye. Another limitation of the technique concerns cellular identification. Penetrated Drosophila cells can be loaded electrophoretically with dyes, including Lucifer yellow or neurobiotin. However, because of the small tip size of the microelectrodes, electrophoresis works less efficiently than with lower resistance electrodes, such as patch-electrodes. Furthermore, the dye-filled microelectrodes characteristically have less favorable electrical properties, making it much harder to record high-quality responses with them from Drosophila photoreceptors and LMCs.
A technical problem that occurs sometimes is unstable input signal, or a complete lack of it. This is often associated with the voltage signal being either constantly drifting or higher/lower than the amplifier's recording range. On most occasions, this behavior is caused by the recording electrode being blocked (or its tip being too fine - having too high a resistance or intramural capacitance - to properly conduct fast signal changes). Although one can try to unblock the tip by buzzing the electrode capacitance, which sometimes works, often the situation is best resolved by simply changing the recording electrode. This may further require parameter adjustments in the microelectrode puller instrument to lower the tip resistance of the new electrodes. The electrode tip can also become blocked in preparations, for which it took too much time to cover the corneal hole by petroleum jelly. Prolonged air-contact can dry up the freshly exposed retinal tissue, turning its surface layer into a glue-like substance. If this is the case, the investigator typically sees a red blob of tissue stuck on the recording electrode when pulling it out of the eye. The only solution here is to make a new preparation. Petroleum jelly may provide many benefits for electrophysiological recordings: (i) it prevents the coagulation of the hemolymph that could break the electrode tip; (ii) it coats the electrode tip reducing its intramural capacitance, which lowers the electrode's time constant, and thus has the potential to improve the temporal resolution of the recorded neural signals40,41; (iii) it keeps the electrode tip clean, facilitating penetrations; and after penetration, (iv) it may even help to seal the electrode tip to the cell membrane42. 
The signal can further be unstable or lost when the silver-chloride wire of the electrode-holder is broken or dechloridized; in which case just replace or rechloridize the old wire. The missing signal can also result from one (or both) of the electrode-holders not being securely connected to their jacks. However, it is extremely unusual that a piece of equipment would be malfunctioning. If signal is undetectable and all other possibilities have been exhausted, test that each part of the recording apparatus, including the headstage, amplifier, low-pass filters and AD/DA-converters, are connected properly and functioning normally. One way to achieve this is to replace each instrument with another from a rig that is known to operate normally. Alternatively, use a signal generator to check the performance of the electronic components one by one.
But perhaps the most common technical problem facing the electrophysiologist is that of recording noise. Broadly, recording noise is the observed electrical activity other than the direct neuronal response to a given stimulus. Because the fly preparation, when properly done, is very stable, the observed noise (beyond the natural variably of the responses) most often results from ground-loops in the recording equipment, or is picked up from nearby electrical devices. Such noise is typically 50/60 Hz mains hum and its harmonics; but sometimes composed of more complex waveforms. To work out the origin of the noise, remove the fly preparation holder from the set-up, connect the recording and reference electrodes through a drop of fly Ringer (or place them in a small Ringer's solution bath; see step 1.2.6) and record the signal in CC- or bridge-mode. If noise is observable on the recorded signal, this likely means that the noise is external to the fly preparation.
Another good test for identifying the origin of noise is to replace the electrode-holders with an electric cell model connected to the amplifier. In an ideally configured and grounded set-up, the recorded signal should now be practically noise-free, showing only stochastic bit-noise from the AD-converter (in the best case not even that!). If noise is still present, then recheck that all rig equipment is properly grounded. A convenient approach to detect ground-loops is to: (i) disconnect all the grounding wires from all the parts within the rig; (ii) ensure that, after doing this, every single part is actually isolated from ground, by means of an ohm-meter; (iii) connect the parts, one by one, to the central ground directly, not through any other part of the rig. Try also changing the equipment configurations. For example, sometimes moving the computer and monitor further away from the rig can reduce noise; yet at other times, moving the computer inside the equipment rack reduces noise. It is also worth unplugging nearby equipment to see if noise is reduced, or shield additional components. Furthermore, try unplugging or replacing different components of the recording equipment, especially BNC cables (which can have faulty ground connections). If only bit-noise is observed when using the cell model, the initial noise source is either the electrodes or the fly preparation itself. For example, it could be that the reference electrode is inadvertently touching a motor nerve or active muscle fibers inside the head capsule (or disturbing flight muscles in the thorax - if placed there). It is usually simplest to prepare a new fly for recording, taking care to minimize damage to the fly. But if the noise persists and is broadband, it is likely that the electrodes are suboptimal for the experiments; too sharp/fine (hence too noisy) or just wrong for the purpose; we have even seen quartz-electrodes acting as antennas - picking up faint broadcasting signals! Although iteration of the puller-instrument parameter settings to generate the just right microelectrodes for consistent high-quality recordings from specific cell-types can take a lot of effort, it is worth it. Once the recording electrodes are well-tailored for the experiments, they can provide long-lasting recordings of outstanding quality.
Sharp microelectrode recording techniques can be similarly applied to study neural information processing in multitude of preparations, including different processing layers in the insect eyes and brain43,44. Because the microelectrode tips can be made very fine, these typically damage the studied cells less than most patch-clamp applications. Importantly, the modern sample-and-hold microelectrode amplifiers enable good control of the tips' electrical properties40,45-47. Thus, when correctly applied, this technique can provide reliable data from both in vivo3,5,7-10,44 or in vitro48 preparations with high signal-to-noise ratio at sub-millisecond resolution. Such precision would be impossible with today's optical imaging techniques, which are noisier and slower. Moreover, the method can be used to characterize small cells' electrical membrane properties both in current- and voltage-clamp configurations5,29,33,36,40-42,49, providing valuable data for biophysical and empirical modeling approaches7,8,11,33,49-54 that link experiments to theory.

초파리 (Drosophila의 melanogaster의) 화합물의 눈은 신경 이미지 샘플링 및 처리를위한 광 수용체 및 interneuron 배열의 기능적 조직을 조사 할 수있는 좋은 모델 시스템이며, 동물 비전. 시스템은 가장 완벽한 배선도 1,2-을 가지며 유전자 조작 및 3-10 (높은 신호 - 대 - 잡음 비율 및 시간 해상도) 정확한 신경 활동 모니터링에 호감이다. 초파리의 눈은 함께가 머리 주위 거의 모든 방향을 커버하는 탁 트인 시야 비행을 제공 ommatidia, 개안라고 ~ 750 겉으로는 일반 렌즈 덮인 구조를 포함하는 모듈이다. 단위는 rhabdomeric 광 수용체 7,8,11 있습니다 샘플링 눈의 주요 정보를 제공합니다. 각 개안은 같은면 렌즈를 공유하지만, 일곱 가지 방향으로 정렬됩니다 팔 광 수용체 세포 (R1-R8)를 포함한다. 외부 광 수용체 R1-R6 아칸소 동안전자 파란색 - 녹색 빛에 가장 민감, 같은 방향으로 서로 지점의 상단에 거짓말 내부 세포 R7과 R8의 스펙트럼 감도, 전시 세 가지 독특한 하위 유형이 : 창백한 노란색과 지느러미 가장자리 영역 (DRA) 12 15. <img alt="그림 1" src="/files/ftp_upload/54142/54142fig1.jpg" /> 그림 1. 초파리 눈의 기능 조직. (A) 두 최초의 광학 신경, 망막과 얇은 판은 플라이 눈 안쪽 회색으로 강조 표시됩니다. 망막 R1-R6의 광 수용체와 얇은 대형 모노 폴라 셀 (중저 소득 : L1-L3)는 기존의 날카로운 미세 전극 녹음에 생체 내에서 쉽게 액세스 할 수 있습니다. 개략적 전극 망막 R1-R6에서 기록하는 정상 경로를 강조한다. 라미에 중저 소득 국가에서 기록하는 하나의 경로는 왼쪽으로 평행 전극으로 이동하는 것입니다. (B)는 얇은 판 retinotopically 기관의 행렬시각적 공간에서 특정 작은 영역에서 정보를 처리하는 신경 세포들이 즐비 각각화된 카트리지. 신경 중첩으로 인해, 다른 이웃 ommatidia, 개안로부터 6 광 수용체는 L1-L3와 무 축삭 세포 (암)에 히스타민 출력 시냅스를 형성, 동일한 라미 카트리지에 자신의 축삭 (R1-R6)를 보낼 수 있습니다. (C) R1-R6 엑손 단자와 라미 카트리지 복잡한 내부 (L4, L5, Lawf, C2, C3 및 T1 포함) 사이의 interneurons 시각 신경 정보의 확산. (D) R1-R6의 광 수용체의 축삭은 L2 및 L4 극성 세포에서 시냅스 피드백을받을 수 있습니다. 리베라 - 알바 등의 알 2에서 수정 (B)와 (C). <a href="https://www.jove.com/files/ftp_upload/54142/54142fig1large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> 초파리의 눈은 신경 중첩 형 (16)이다. 이 t를 의미한다라미와 수질 : 모자는 공간에서 같은 지점에서 볼 ommatidia, 개안 이웃 일곱에 속하는 여덟 광 수용체의 신경 신호는 다음 두 neuropils 한 신경 카트리지에서 함께 풀링됩니다. 여섯 외부 광 수용체 라미에 신경 컬럼에 자신의 축삭 단자 R1-R6 프로젝트 (그림 1), R7 및 R8 세포는이 계층을 무시하고 자신이 수질 열 17-19 대응 시냅스 접촉을하는 동안. 이러한 정확한 배선은 모든 얇은 판 (도 1A-C) 그러자, 비행 초기 비전의 retinotopic 매핑에 대한 신경 기판을 생산하고 수질 열 (카트리지) 공간에서 하나의 지점을 나타냅니다. 라미 1,2,20에서와 무 축삭 세포 (암) : R1-R6의 광 수용체에서 직접 입력은 대형 모노 폴라 셀 (L1, L2 및 L3 중저 소득)에 의해 수신된다. 이 중, L1 및 L2 주요 정보 경로 (그림 1D)를 매개하는 가장 큰 세포는, WHI 있습니다채널의 응답은 온 및 오프 에지를 이동함으로써, 움직임 검출부 (21, 22)의 계산 근거를 형성한다. L2 세포 23, 24의 L1에에 전면 후면 및 전면에서 후면 : 행동 실험은 중간 반면에, 두 개의 경로가 반대 방향의 모션 인식을 용이하게 제안합니다. 연결은 또한 L4 뉴런 이웃 카트리지 (25, 26) 사이의 측 방향 연통 중요한 역할을 할 수 있다는 것을 의미한다. 상호 시냅스는 L2 및 L4 동일한에있는 세포와 두 개의 인접한 카트리지 사이에 발견되었다. 다운 스트림, 각각의 L2 셀과 세 개의 관련 L4 세포가 공통의 목표에 자신의 축삭 프로젝트, 이웃 카트리지에서 입력이 생각하는 수질에있는 TM2 신경 세포는 전후 운동 (27)의 처리를 위해 통합 될 수 있습니다. L1 신경 세포가 모두 갭 접합과 시냅스를 통해 동일한 카트리지 L2S에서 입력을받을 수 있지만, 그들은 직접 L4s 따라서 인접 라미 카트리지에 연결되어 있지 않습니다. <p클래스 = &quot;jove_content&quot;&gt; R1-R6의 광 수용체의 축색 돌기에 시냅틱 피드백은 L2 / L4 회로에 속하는 뉴런 만 제공 아니라 L1 경로의 1, 2 (그림 1D). 같은 카트리지 연결이 R1과 R2에 L2로부터 L4에서 R5에 선택적으로있는 동안, 모든 R1-R6의 광 수용체 중 하나의 L4 또는 둘 모두 이웃 카트리지에서 시냅스 피드백을받을 수 있습니다. 또한, R1, R2, R4 및 R5로 오전 강한 시냅스 연결이 있고, 신경교 세포는 시냅스 네트워크에 연결되어 있으므로 신경 화상 처리부 (6)에 참가할 수있다. 마지막으로, 얇은 판에서 R1-R6 및 R6 및 R7 / R8 사이의 광 수용체 이웃 연결 축삭 갭 접합은, 각 카트리지 14,20,28에서 비대칭 정보의 표현 및 처리에 기여한다. 거의 그대로 초파리에서 개별 광 수용체 및 시각의 interneurons에서 세포 내 전압 녹음은 높은 신호 대 잡음 연구를 제공연결된 뉴런 사이의 빠른 신경 계산의 의미를 만들기 위해 필요한 서브 밀리 초 해상도 3,5,7-10,29,에서 다음 페이지에 계속 데이터. 100 밀리 초 해상도 - 정밀도 수준은 상당히 잡음이 있고 일반적으로 10으로 동작 전류 결상 기술에 의해 불가능하다. 전극은 매우 작고 날카로운 팁을 가지고 있기 때문에 또한,이 방법은 세포 기관에 한정되지 않고, 작은 활성 신경 구조의 직접 기록을 제공 할 수있다; 이러한 패치 클램프 전극의 훨씬 더 큰 팁에 액세스 할 수없는 중저 소득 &#39;수지상 나무 또는 광 수용체의 축색 돌기, 등. 중요한 것은,이 방법은 또한 대부분의 패치 클램프 애플리케이션보다 덜 침습적 구조적 손상이기 때문에 적은 연구 세포의 세포 내 환경 정보 샘플링에 영향을 미친다. 따라서, 기존의 날카로운 미세 기술이 기여하고, 신경 INFOR으로, 근본적인 발견과 원래의 통찰력을 기여 계속했다적절한 시간 규모 메이션 처리; 비전 3-10 우리의 기계론의 이해를 향상시킬 수있다. 초파리 R1-R6의 광 수용체 및 중저 소득 국가에서 생체 세포 내 녹음에 Juusola 실험실에서 수행하는 방법이 문서에서는 설명합니다. 이 프로토콜은, 적절한 전기 생리학 장비를 구성하는 방법에 대해 설명 비행을 준비하고 녹음을 수행합니다. 일부 대표 데이터를 제시하고, 몇 가지 일반적인 문제와 잠재적 인 솔루션은이 방법을 사용할 때 발생 될 수있는 논의된다.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Stereo Zoom Microscope for making the fly preparation</td>
			<td>Olympus</td>
			<td>SZX12 DFPLFL1.6x PF eyepieces: WHN30x-H/22</td>
			<td>Capable of ~150X magnification with long working distance; bespoke heavy steel table mount stand</td>
		</tr>
		<tr>
			<td rowspan="2">Stereomicroscope in the intracellular set-up</td>
			<td>&#183;&#160; Olympus</td>
			<td>Olympus SZX7; eyepieces: WHN30x-H/22</td>
			<td rowspan="2">30x eyepieces are needed for seeing the electrode tip reflections well when driving it through the small corneal hole into the eye</td>
		</tr>
		<tr>
			<td>&#183;&#160; Nikon</td>
			<td>Nikon SMZ645; eyepieces: C-W30x/7</td>
		</tr>
		<tr>
			<td rowspan="2">Anti-vibration Table</td>
			<td>&#183;&#160; Melles Griot</td>
			<td rowspan="2">With metric M6 holes on the breadboard</td>
			<td rowspan="2">Our bespoke rigs have a large hole drilled through the thick breadboard that lets in the fly preparation platform pole (houses a copper heatsink with electronics) from below</td>
		</tr>
		<tr>
			<td>&#183;&#160; Newport</td>
		</tr>
		<tr>
			<td rowspan="4">Micromanipulators</td>
			<td>&#183;&#160; Narishige</td>
			<td>&#183;&#160; Narishige NMN-21</td>
			<td rowspan="4">In our intracellular set-ups, different micromanipulator systems are used for driving the shap recording electrodes into the fly eye. All the listed manipulators are succesfully providing long-lasting stable recordings from Drosophila photoreceptors and LMCs.&#160;</td>
		</tr>
		<tr>
			<td>&#183;&#160; Huxley Bertram</td>
			<td>&#183;&#160; Huxley xyz-axis with fine manual control</td>
		</tr>
		<tr>
			<td>&#183;&#160; Sensapex</td>
			<td>&#183;&#160; Sensapex triple axis</td>
		</tr>
		<tr>
			<td>&#183;&#160; M&#228;rzh&#228;user</td>
			<td>&#183;&#160; M&#228;rzh&#228;user DC-3K with additional x-axis piezo stepper and MS 314 controller</td>
		</tr>
		<tr>
			<td>Magnetic Stands</td>
			<td>Any magnetic base with on/off switch will do</td>
			<td></td>
			<td>For example, to manage cables inside the Faraday cage</td>
		</tr>
		<tr>
			<td>Electrode Holders</td>
			<td>Harvard Apparatus</td>
			<td>ESP/W-F10N</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver Wire</td>
			<td>World Precision Instruments&#160;</td>
			<td>AGW1510</td>
			<td>0.3-0.5 mm diameter; needs to be chloridized for the electrode holders</td>
		</tr>
		<tr>
			<td>Fiber Optic Light Source</td>
			<td>Many different, including Olympus</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Fiber Optic Bundles</td>
			<td>&#183;&#160; UltraFine Technology</td>
			<td rowspan="2"></td>
			<td rowspan="2">To deliver the LED light stimulus to the Cardan arm system. We use both liquid and quartz light guides (range from UV to IR)</td>
		</tr>
		<tr>
			<td>&#183;&#160; Thorn Labs</td>
		</tr>
		<tr>
			<td>Fly Cathing Tube</td>
			<td></td>
			<td>P80-50P 50ml Cent. Tube PP., Pack of 100 Pcs</td>
			<td>Cut the conical bottom off from 50 ml Plastic Centrifuge Tube and glue a 1 ml pipette tip on it.</td>
		</tr>
		<tr>
			<td>Digital Acquisition System</td>
			<td>National Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Single-electrode current/voltage-clamp microelectrode amplifier</td>
			<td>npi SEC-10LX</td>
			<td>http://www.npielectronic.de/products/amplifiers/sec-single-electrode-clamp/sec-10lx.html</td>
			<td>Outstanding performer!</td>
		</tr>
		<tr>
			<td>Head-stage</td>
			<td>Standard (+/- 150 nA)</td>
			<td>For npi SEC-10LX</td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">LED light sources and drivers</td>
			<td>&#183;&#160; 2-channel OptoLED (Cairn Research Ltd., UK)</td>
			<td rowspan="2"></td>
			<td rowspan="2">Many of our stimulus systems are in-house built&#160;</td>
		</tr>
		<tr>
			<td>&#183;&#160; Self-designed and constructed</td>
		</tr>
		<tr>
			<td>Acquisition and Analyses Software</td>
			<td>Many companies to choose from</td>
			<td></td>
			<td>Biosyst; custom written Matlab-based system for experimental and theoretical work in the Juusola laboratory</td>
		</tr>
		<tr>
			<td>Personal Computer or Mac</td>
			<td></td>
			<td></td>
			<td>Ensure that PC or Mac is compatible with data acquisition system and software</td>
		</tr>
		<tr>
			<td>Cardan arm system&#160;</td>
			<td>Self-designed and constructed</td>
			<td></td>
			<td>Providing accurate x,y,z-positioning of the light stimuli</td>
		</tr>
		<tr>
			<td>Peltier temperature control system&#160;</td>
			<td>Self-designed and constructed</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Faraday Cage</td>
			<td>Self-constructed</td>
			<td></td>
			<td>Electromagnetic noise shielding</td>
		</tr>
		<tr>
			<td rowspan="2">Filamented Borosilicate Glass Capillaries</td>
			<td rowspan="2"></td>
			<td>Outer diameter: 1 mm</td>
			<td rowspan="2"></td>
		</tr>
		<tr>
			<td>Inner diameter: 0.5-0.7 mm</td>
		</tr>
		<tr>
			<td rowspan="2">Filamented Quartz Glass Capillaries</td>
			<td rowspan="2"></td>
			<td>Outer diameter: 1 mm</td>
			<td rowspan="2"></td>
		</tr>
		<tr>
			<td>Inner diameter: 0.5-0.7 mm</td>
		</tr>
		<tr>
			<td>Pipette Puller</td>
			<td>Sutter Instrument Company</td>
			<td>Model P-2000 laser Flaming/Brown Micropipette Puller</td>
			<td>For borosilicate reference electrodes, use the preset program #11 (patch electrodes): Heat = 350; Filament = 4; Velocity 36; Delay = 200).1.2.1). For borosilicate recording electrodes, use the preset program #12 (this typically pulls good conventional sharps&#160; for photoreceptor recordings): Heat = 355; Filament = 4; Velocity 50; Delay = 225; Pull = 150. For LMC recordings, which require electrodes with finer tips, these values need to be adjusted. For pulling quartz capillaries, P-2000 manual suggests programs for fine tipped microelectrodes. These programs&#8217; preset parameters serve as useful starting points for systematic modifications to generate electrodes with good penetration success and low recording noise.</td>
		</tr>
		<tr>
			<td>Extracellular Ringer Solution for the reference electrode</td>
			<td>Chemicals from Fisher Scientific</td>
			<td>10326390, NaCl 10010310, KCl 10147753, TES 10161800, CaCl2 10159872, MgCl2 10000430, sucrose</td>
			<td>See the recipe in the protocol section</td>
		</tr>
		<tr>
			<td>3 M KCl solution for filling the filamented recording microelectrode</td>
			<td>Salts from Fisher Scientific</td>
			<td>10010310, KCl</td>
			<td></td>
		</tr>
		<tr>
			<td>Petroleum jelly</td>
			<td>Vaselin</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Non-stainless steel razor blades</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Blade holder/breaker</td>
			<td>Fine Science Tools By Dumont</td>
			<td>10053-09</td>
			<td>9 cm</td>
		</tr>
		<tr>
			<td>Blu-tack</td>
			<td>Bostik</td>
			<td></td>
			<td>Alternatively, use molding clay</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>Fine Science Tools By Dumont</td>
			<td>11252-00</td>
			<td>#5SF (super-fine tips)</td>
		</tr>
	</tbody>
</table>

electrophysiological method for recording intracellular voltage responses of drosophila photoreceptors and interneurons to light stimuli in vivo

Voltage responses of insect photoreceptors and visual interneurons can be accurately recorded with conventional sharp microelectrodes. The method described here enables the investigator to measure long-lasting (from minutes to hours) high-quality intracellular responses from single Drosophila R1-R6 photoreceptors and Large Monopolar Cells (LMCs) to light stimuli. Because the recording system has low noise, it can be used to study variability among individual cells in the fly eye, and how their outputs reflect the physical properties of the visual environment. We outline all key steps in performing this technique. The basic steps in constructing an appropriate electrophysiology set-up for recording, such as design and selection of the experimental equipment are described. We also explain how to prepare for recording by making appropriate (sharp) recording and (blunt) reference electrodes. Details are given on how to fix an intact fly in a bespoke fly-holder, prepare a small window in its eye and insert a recording electrode through this hole with minimal damage. We explain how to localize the center of a cell's receptive field, dark- or light-adapt the studied cell, and to record its voltage responses to dynamic light stimuli. Finally, we describe the criteria for stable normal recordings, show characteristic high-quality voltage responses of individual cells to different light stimuli, and briefly define how to quantify their signaling performance. Many aspects of the method are technically challenging and require practice and patience to master. But once learned and optimized for the investigator's experimental objectives, it grants outstanding in vivo neurophysiological data.

초파리 눈 여기 구성된 같이 날카로운 미세 기록 방법은, 확실하게 그들 사이 4,5,7,8,10,33 신경 정보의 샘플링 처리 망막 및 점막 세포와의 통신을 정량화하는데 사용될 수있다. 다른 야생형 주식, 돌연변이 또는 유전자 조작 플라이 균주 인코딩 공부를 사용함으로써,이 방법은 그 값을 입증되었다; 뿐만 아니라 변이, 온도, 다이어트 또는 선택된 발현 3,4,6,9,10,14,30,34의 효과를 정량화 할뿐만 아니라 변경된 시각적 행동 14, 34에 대한 역학적 원인을 공개한다. 상기 방법은 또한 neuroethological 비전 연구를 실어 다른 곤충 제제 (35, 36)에 용이하게 적용될 수있다. 다음에 우리는 성공적인 응용 프로그램의 몇 가지 예를 소개. <img alt="그림 7" src="/files/ftp_upload/54142/54142fig7.jpg" /> 그림 7. 전압빛 (20)의 펄스와에 과일 플라이 R1-R6 광 수용체의 응답 (25) 오 날카로운 미세 관통은 종종 매우 안정적이기 때문에 C.,에서 주어진 빛 자극에 동일한 R1-R6의 광 수용체의 전압 응답을 기록 할 수있다 온난화 또는 즉시 냉각하여 다른 주위 온도. 우리의 셋업에서, 파리 홀더 가까운 루프 펠티에 소자 기반의 온도 제어 시스템에 배치됩니다. 이 초 파리의 헤드 온도를 변경하는 우리를 할 수 있습니다. 높은 온도는 전압 응답을 가속화하고 특징적으로 (빨간색 화살표로 표시된 바와 같이) R1-R6의 광 수용체의 휴식 가능성을 낮춘다. <a href="https://www.jove.com/files/ftp_upload/54142/54142fig7large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> 광 수용체 출력에 온도의 효과를 공부 O를 C (그림 7)에서 동일한 R1-R6의 광 수용체에 기록 밝은 10 밀리 긴 펄스에 전압 응답을 보여줍니다. 4,9 전에 정량으로, 온난화는 어둠 속에서 감광체의 휴식 가능성을 낮추고, 그 전압 응답을 가속화합니다. <img alt="그림 8" src="/files/ftp_upload/54142/54142fig8.jpg" /> 그림 8. 시그널링 성능 과일 플라이 R1-R6 광 수용체는 빛의 강도와 개선 (A) 시각 출력 (아래) 어둡게하고 밝은. (위의 10,000 배 밝은 빛) 같은 미세 전극에 의해 기록 자연 빛의 강도의 시계열을 반복20 O C.에서 같은 셀 그들은 더 많은 샘플, 단일 광자 4,5,7,8에 대한 기본 응답 (범프)를 통합하기 때문에 밝은 자극에 대한 반응이 크다. (B) 20 연속 1 초 동안 전압 응답이 중첩된다. 개별 응답 (밝은 회색) (A에서 화살표) 적응 동향 후 찍은 것은 (A에서 점선 상자) 물러했다. 대응하는 응답 수단 (신호)는 어두운 흔적이다. 신호 및 각 응답의 차이는 잡음이다. (C) 세포를 표준 방법을 사용하여 4,5,7,8 신호대 잡음비 (SNR) &#39;시그널링 성능은 기록에 의해 정량 하였다.&#39; 광 수용체 출력들과 함께 &#39;(20 Hz에서 최대, 중국식 ≥1 SNR) 희미한보다 (밝은 ≥1, 최대 84 Hz의 밝은 자극에 안정적인 신호의 약 64 Hz의 넓은 범위의 SNR)&#39;이있다ignal 잡음비 크게 개선; SNR 중국식 MAX = SNR 밝은 MAX 87 = 1868에서. <a href="https://www.jove.com/files/ftp_upload/54142/54142fig8large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> 반복적 인 자극에 의해 적응과 신경 인코딩 공부 망막과 얇은 판 구조에서 상대적으로 적은 손상을 일으키는 방법의 비 침습적은 생체 내에서 자신의 근처의 자연 생리 학적 상태에서 다른 빛의 자극에 개별 세포의 신호 전달 성능을 공부에 이상적이다. 8 쇼에게 R1-의 전압 응답도 20 O C에서 희미하고 밝은 반복 자연 빛의 강도의 시계열 자극에 대한 R6의 광 수용체, 그림 9 반면, </strong는&gt; 25 오 C.에서 다른 자연 자극에 다른 R1-R6의 광 수용체와 LMC의 응답을 보여줍니다 동일한 플라이 두 예리한 마이크로 전극, 망막 하나 라미의 다른 세포에 의해 동시 기록이 가능한 30하기에는 너무 곤란하기 때문에 사전 및 시냅스 기록은 두 개의 다른 플라이에서 별도로 수행 하였다. <img alt="그림 9" src="/files/ftp_upload/54142/54142fig9.jpg" /> 25 오 C. (A) (회색) R1-R6와 LMC (검정)에서 반복 자연주의 자극에 과일 플라이 R1-R6 광 수용체와 LMC 그림 9. 전압 응답은 다른 파리와 다른 미소 전극에 의해 기록 된 출력한다. (B) 빛에 표시된 어느 정도의 빛 적응 20 연속 전 (위) 및 개별 응답과 같은 자연 자극 패턴 시냅스 (아래) 응답을 회색어두운 트레이스로서 D 대응하는 응답 수단 (신호). 신호 및 각 응답의 차이는 잡음이다. (C) 세포의 신호대 잡음비 (SNR) &#39;시그널링 성능은 기록에 의해 정량 하였다.&#39; LMC 출력 &#39;(최대 94 Hz의에 R ≥1, SNR) R1-R6 출력보다 (104 Hz에서 최대 LMC ≥1, SNR)&#39;신뢰할 수있는 신호의 약 10 Hz의 넓은 범위를 가지고있다. 두 신호 - 대 - 잡음 비율 (SNR LMC MAX = 142 SNR R MAX = 752) 높고, 기록 노이즈가 낮고 같은 차이점은 셀 간의 실제 인코딩 차이를 반영한다. <a href="https://www.jove.com/files/ftp_upload/54142/54142fig9large.jpg" target="_blank">더 큰 버전을 보려면 여기를 클릭하세요 이 그림.</a> 자극 발병 후, 녹음 전형적인LY 빠른 크게 5 ~ 6 초 이내에 가라 동향을 적응 보여줍니다. 그때부터, 세포를 각 1 초 긴 자극 프레 젠 테이션에 매우 일관된 응답 (각 점선이 20을 둘러싸)을 생산하고 있습니다. 이 (그림 8B 및도 9b)를 중첩 할 때 응답의 반복은 분명해진다. 개별 응답은 얇은 회색 추적하고, 자신은 두꺼운 어두운 추적을 의미한다. 신경 노이즈 평균과 각 응답 4,5,9,37,38 차이 인 반면, 평균 응답은 신경 신호로한다. 주파수 영역에서 각각의 신호 - 대 - 잡음비 (도 8c 및도 9c)는 파워 스펙트럼으로 신호 및 잡음 데이터 청크를 푸리에 변환하고, 대응하는 평균 잡음 전력 스펙트럼 4 평균 신호 전력 스펙트럼을 나눔으로써 얻어졌다 5,9,37,38. 특징적으로, 최대 신호대 잡음비 O자연 자극 기록 신경 출력 (100 - 1000) &gt;&gt; f를 높은 값에 도달 할 수 있고, 매우 낮은 기록 노이즈 가장 안정한 제제 1,000 (예를 들면,도 8c.). 공지 사항은 또한 온난화는 세포 확장 &#39;신호 신뢰성의 대역폭을 4 (SNR&#39;밝은 ≥ 1); 예를 들어,도 8 및 9 개의 R1-R6s 사이의 상대적인 차이는 각각 10 헤르츠 (Hz 84 20 O C 및 94 Hz에서 25 ℃로)이다. 하나는 상기 샤논 수학 식 32를 사용하여 또는 트리플 외삽 법 (39)을 통해 응답 &#39;엔트로피 노이즈 엔트로피 율의 차이를 산출하여 신호대 잡음비의 정보 전송의 각 셀의 속도를 추정 할 수있다. 더 많은 정보 이론적 분석에 대한 세부 사항 및 사용 제한특히이 방법으로 이전 출판물 7,8,39에 나와있다 s의. <img alt="그림 10" src="/files/ftp_upload/54142/54142fig10.jpg" /> 19 오 C. (A) R1-R6 (회색)와 LMC (블랙) 같은 파리에서 같은 미세 전극에 의해 기록 된 출력에서 반복 자연주의 자극에 킬러 플라이 R1-R6 광 수용체와 LMC 그림 10. 전압 응답; 전극이 눈에 진행되었을 때 이후 시냅스 처음 postsynaptically 및. 같은 자연 자극 패턴 (B) (위) 20 연속 사전 및 시냅스 (아래) 응답 (밝은 회색 추적)이 초기 적응 (A에서 점선 상자) 후 촬영 하였다. 각각의 응답에 각각의 차이는 노이즈를 제공하면서 그들의 수단은 신호 (상단에 어두운 흔적을)입니다. (C) 해당 시그나L 잡음비 (SNR)는도 8c 및도 9c에 다음과 같이 계산 하였다. LMC 출력 &#39;(134 Hz에서 최대 R MAX ≥1 SNR) R1-R6 출력 이상 (최대 234 Hz의에 LMC MAX ≥1, SNR)&#39;신뢰할 수있는 신호의 100 Hz의 넓은 범위에 대해이 있습니다. 두 신호 - 대 - 잡음 비율 (SNR LMC MAX = 137 SNR R MAX = 627) 높고, 동일한 미세이 녹음에 사용 된 바와 같이, 그 차이가 사전 및 시냅스 신경 출력에서 실제 차이를 반영한다. 이러한 결과는 기록 시스템이 낮은 노이즈가 있고, 분석에 미치는 영향이 한계였다. 것을 의미하는 <a href="https://www.jove.com/files/ftp_upload/54142/54142fig10large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> Neuroethological 비전 연구 </p&gt; 상기 방법은 또한 시각적 정보 처리 neuroethological 비교 연구를 허용하는 다른 곤충 7,8,35,36 종의 화합물의 눈 (도 10)의 사전 및 시냅스 전압 응답을 기록하는데 사용될 수있다. 제시된 기록 시스템의 경우, 필요한 유일한 적응은 연구 종에 대한 적절한 크기의 구멍을 가진 새로운 준비 홀더, 각이다. 이 예시적인 기록은 여성 킬러 비행 (Coenosia의 attenuata)의 출신. 이들은도 9에 대응 초파리에서 사용 된 것과 동일한 반복 광 자극에 R1-R6 수광부와 LMC 전압의 세포 내 반응을 보여 주지만, 19 ℃에서 O 이 경우, 사전 및 시냅스 데이터 모두 동일한 플라이로 기록되었다; 하나의 제 횡 박판으로 진행 (3 M KCl을 가득) 동일한 기록 전극과, 다른 하나는 이전에 입력 한 후정면 망막을 보내고. 심지어 냉각기 온도 - - 25 O C의 Coenosia 데이터의 초파리 데이터와 비교하여 빠른 반응 역학을 나타낸다 안정적인 신호 (신호 대 잡음비 &gt;&gt; 1)는 넓은 주파수 범위의 범위를 확대. 자연 자극의 신경 인코딩에서 이러한 기능 적응이 빠른 공중 사냥 행동을 달성하기 위해 고정밀 시공간 정보를 필요로 Coenosia의 약탈 라이프 스타일 (36)과 일치한다.

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Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

Sharp microelectrodes enable accurate electrophysiological characterization of photoreceptor and visual interneuron output in living Drosophila. Here we show how to use this method to record high-quality voltage responses of individual cells to controlled light stimulation. This method is ideal for studying neural information processing in insect compound eyes.

의 기록 세포 내 전압 응답에 대한 전기 생리 방법<em&gt; 초파리</em&gt; 빛 자극에 광수와의 interneurons<em&gt; 생체</em

Voltage responses of insect photoreceptors and visual interneurons can be accurately recorded with conventional sharp microelectrodes. The method ...

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Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

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18.5K 조회수.  Beijing Normal University. Sharp microelectrodes enable accurate electrophysiological characterization of photoreceptor and visual interneuron output in living Drosophila. Here we show how to use this method to record high-quality voltage responses of individual cells to controlled light stimulation. This method is ideal for studying neural information processing in insect compound eyes.

비디오: Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

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

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

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

급성 Hippocampal 슬라이스에 Synaptically-evoked Astroglial와 Neuronal 응답의 듀얼 Electrophysiological 레코딩

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

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신경과학

A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant characteristics.&#160;This precludes a rational selection of a particular implant as optimal for a particular application and the development of new materials based on the most critical performance parameters.&#160;This article develops a protocol for in vitro and in vivo testing of neural recording electrodes.&#160;Recommended parameters for electrochemical and electrophysiological testing are documented with the key steps and potential issues discussed.&#160;This method eliminates or reduces the impact of many systematic errors present in simpler in vivo testing paradigms, especially variations in electrode/neuron distance and between animal models.&#160;The result is a strong correlation between the critical in vitro and in vivo responses, such as impedance and signal-to-noise ratio.&#160;This protocol can easily be adapted to test other electrode materials and designs.&#160;The in vitro techniques can be expanded to any other nondestructive method to determine further important performance indicators.&#160;The principles used for the surgical approach in the auditory pathway can also be modified to other neural regions or tissue.

Different electrode coatings affect neural recording performance through changes to electrochemical, chemical and mechanical properties. Comparison of electrodes in vitro is relatively simple, however comparison of in vivo response is typically complicated by variations in electrode/neuron distance and between animals. This article provides a robust method to compare neural recording electrodes.

신경 기록 전극의 체계적인 전기 및 전기 생리 평가를위한 방법

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant ...

Electrophysiological Recording From Drosophila Labellar Taste Sensilla

The peripheral taste response of insects can be powerfully investigated with electrophysiological techniques. The method described here allows the researcher to measure gustatory responses directly and quantitatively, reflecting the sensory input that the insect nervous system receives from taste stimuli in its environment. This protocol outlines all key steps in performing this technique. The critical steps in assembling an electrophysiology rig, such as selection of necessary equipment and a suitable environment for recording, are delineated. We also describe how to prepare for recording by making appropriate reference and recording electrodes, and tastant solutions. We describe in detail the method used for preparing the insect by insertion of a glass reference electrode into the fly in order to immobilize the proboscis. We show traces of the electrical impulses fired by taste neurons in response to a sugar and a bitter compound. Aspects of the protocol are technically challenging and we include an extensive description of some common technical challenges that may be encountered, such as lack of signal or excessive noise in the system, and potential solutions. The technique has limitations, such as the inability to deliver temporally complex stimuli, observe background firing immediately prior to stimulus delivery, or use water-insoluble taste compounds conveniently. Despite these limitations, this technique (including minor variations referenced in the protocol) is a standard, broadly accepted procedure for recording Drosophila neuronal responses to taste compounds.

Electrophysiological Recording From Drosophila Labellar Taste Sensilla

This protocol describes extracellular recording of the action potential responses fired by labellar taste neurons in Drosophila.

에서 전기 생리학 기록<em&gt; 초파리</em&gt; Labellar는 Sensilla 맛

The peripheral taste response of insects can be powerfully investigated with electrophysiological techniques. The method described here allows the ...

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.

에 가이드<em&gt; 생체</emOptogenetically 확인 된 대뇌 피질의 억제의 interneurons에서&gt; 단일 단위 기록

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

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at the synaptic level. The Active Zone (AZ) is the region at the presynaptic membrane that mediates neurotransmitter release and is composed of a dense collection of scaffold proteins. AZs of Drosophila melanogaster (Drosophila) photoreceptors undergo molecular remodeling after prolonged exposure to natural ambient light. Thus the level of neuronal activity can rearrange the molecular composition of the AZ and contribute to the regulation of the functional output.
Starting from the light exposure set-up preparation to the immunohistochemistry, this protocol details how to quantify the number, the spatial distribution, and the delocalization level of synaptic molecules at AZs in Drosophila photoreceptors. Using image analysis software, clusters of the GFP-fused AZ component Bruchpilot were identified for each R8 photoreceptor (R8) axon terminal. Detected Bruchpilot spots were automatically assigned to individual R8 axons. To calculate the distribution of spot frequency along the axon, we implemented a customized software plugin. Each axon&#39;s start-point and end-point were manually defined and the position of each Bruchpilot spot was projected onto the connecting line between start and end-point. Besides the number of Bruchpilot clusters, we also quantified the delocalization level of Bruchpilot-GFP within the clusters. These measurements reflect in detail the spatially resolved synaptic dynamics in a single neuron under different environmental conditions to stimuli.

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

Here we show how to quantify the number and spatial distribution of synaptic active zones in Drosophila melanogaster&#160;photoreceptors, highlighted with a genetically encoded molecular marker, and their modulation after prolonged exposure to light.

의 시냅틱 변조 분석<em&gt; 노랑 초파리</em&gt; 장시간 빛에 노출 후 광수

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at ...

Electrophysiological Method for Whole-cell Voltage Clamp Recordings from Drosophila Photoreceptors

Whole-cell voltage clamp recordings from Drosophila melanogaster photoreceptors have revolutionized the field of invertebrate visual transduction, enabling the use of D. melanogaster molecular genetics to study inositol-lipid signaling and Transient Receptor Potential (TRP) channels at the single-molecule level. A handful of labs have mastered this powerful technique, which enables the analysis of the physiological responses to light under highly controlled conditions. This technique allows control over the intracellular and extracellular media; the membrane voltage; and the fast application of pharmacological compounds, such as a variety of ionic or pH indicators, to the intra- and extracellular media. With an exceptionally high signal-to-noise ratio, this method enables the measurement of dark spontaneous and light-induced unitary currents (i.e.&#160;spontaneous and quantum bumps) and macroscopic Light-induced Currents (LIC) from single D. melanogaster photoreceptors. This protocol outlines, in great detail, all the key steps necessary to perform this technique, which includes both electrophysiological and optical recordings. The fly retina dissection procedure for the attainment of intact and viable ex vivo isolated ommatidia in the bath chamber is described. The equipment needed to perform whole-cell and fluorescence imaging measurements are also detailed. Finally, the pitfalls in using this delicate preparation during extended experiments are explained.

Electrophysiological Method for Whole-cell Voltage Clamp Recordings from Drosophila Photoreceptors

Whole-cell recordings from Drosophila melanogaster photoreceptors enable the measurement of spontaneous dark bumps, quantum bumps, macroscopic responses to light, and current-voltage relationships under various conditions. In combination with D. melanogaster genetic manipulation tools, this method enables the study of the ubiquitous inositol-lipid signaling pathway and its target, the TRP channel.

전 세포 전압 클램프 기록을위한 전기 생리 학적 방법<em&gt; Drosophila</em&gt; 광 수용체

Whole-cell voltage clamp recordings from Drosophila melanogaster photoreceptors have revolutionized the field of invertebrate visual transduction, ...

Electrophysiological Recording from Drosophila Trichoid Sensilla in Response to Odorants of Low Volatility

Insects rely on their sense of smell to guide a wide range of behaviors that are critical for their survival, such as food-seeking, predator avoidance, oviposition, and mating. Myriad chemicals of varying volatilities have been identified as natural odorants that activate insect Olfactory Receptor Neurons (ORNs). However, studying the olfactory responses to low-volatility odorants has been hampered by an inability to effectively present such stimuli using conventional odor-delivery methods. Here, we describe a procedure that permits the effective presentation of low-volatility odorants for in vivo Single-Sensillum Recording (SSR). By minimizing the distance between the odor source and the target tissue, this method allows for the application of biologically salient but hitherto inaccessible odorants, including palmitoleic acid, a stimulatory pheromone with a demonstrated effect on ORNs involved in courtship and mating behavior1. Our procedure thus affords a new avenue to assay a host of low-volatility odorants for the study of insect olfaction and pheromone communication.

Electrophysiological Recording from Drosophila Trichoid Sensilla in Response to Odorants of Low Volatility

The overall goal of this protocol is to demonstrate how to present odorants of low volatility for single-sensillum recording from Drosophila olfactory receptor neurons that respond to long-chain cuticular pheromones.

에서 전기 생리 학적 기록<em&gt; Drosophila</em&gt; 낮은 휘발성의 냄새에 반응하는 Trichoid Sensilla

Insects rely on their sense of smell to guide a wide range of behaviors that are critical for their survival, such as food-seeking, predator avoidance, ...

Ex Vivo Calcium Imaging for Visualizing Brain Responses to Endocrine Signaling in Drosophila

Organ-to-organ communication by endocrine signaling, for example, from the periphery to the brain, is essential for maintaining homeostasis. As a model animal for endocrine research, Drosophila melanogaster, which has sophisticated genetic tools and genome information, is being increasingly used. This article describes a method for the calcium imaging of Drosophila brain explants. This method enables the detection of the direct signaling of a hormone to the brain. It is well known that many peptide hormones act through G-protein-coupled receptors (GPCRs), whose activation causes an increase in the intracellular Ca2+concentration. Neural activation also elevates intracellular Ca2+ levels, from both Ca2+ influx and the release of Ca2+ stored in the endoplasmic reticulum (ER). A calcium sensor, GCaMP, can monitor these Ca2+ changes. In this method, GCaMP is expressed in the neurons of interest, and the GCaMP-expressing larval brain is dissected and cultured ex vivo. The test peptide is then applied to the brain explant, and the fluorescent changes in GCaMP are detected using a spinning disc confocal microscope equipped with a CCD camera. Using this method, any water-soluble molecule can be tested, and various cellular events associated with neural activation can be imaged using the appropriate fluorescent indicators. Moreover, by modifying the imaging chamber, this method can be used to image other Drosophila organs or the organs of other animals.

Ex Vivo Calcium Imaging for Visualizing Brain Responses to Endocrine Signaling in Drosophila

This paper describes a protocol for ex vivo calcium imaging of the Drosophila brain. In this method, natural or synthetic compounds can be applied to the buffer to test their ability to activate particular neurons in the brain.

전 비보 내 분 비 신호 초파리 에 두뇌 응답을 시각화 칼슘 이미징

Organ-to-organ communication by endocrine signaling, for example, from the periphery to the brain, is essential for maintaining homeostasis. As a model ...

Preparing Adult Drosophila melanogaster for Whole Brain Imaging during Behavior and Stimuli Responses

We present a method developed specifically to image the whole Drosophila brain during ongoing behavior such as walking. Head fixation and dissection are optimized to minimize their impact on behavior. This is first achieved by using a holder that minimizes movement hindrances. The back of the fly&#8217;s head is glued to this holder at an angle that allows optical access to the whole brain while retaining the fly&#8217;s ability to walk, groom, smell, taste and see. The back of the head is dissected to remove tissues in the optical path and muscles responsible for head movement artefacts. The fly brain can subsequently be imaged to record brain activity, for instance using calcium or voltage indicators, during specific behaviors such as walking or grooming, and in response to different stimuli. Once the challenging dissection, which requires considerable practice, has been mastered, this technique allows to record rich data sets relating whole brain activity to behavior and stimulus responses.

Preparing Adult Drosophila melanogaster for Whole Brain Imaging during Behavior and Stimuli Responses

We present a method specifically tailored to image the whole brain of adult Drosophila during behavior and in response to stimuli. The head is positioned to allow optical access to the whole brain, while the fly can move its legs and the antennae, the tip of the proboscis, and the eyes can receive sensory stimuli.

행동과 자극 반응 도중 전체 두뇌 화상 진찰을 위한 성인 Drosophila melanogaster를 준비합니다

We present a method developed specifically to image the whole Drosophila brain during ongoing behavior such as walking. Head fixation and dissection are ...

In vivo Calcium Imaging of Mouse Geniculate Ganglion Neuron Responses to Taste Stimuli

Within the last ten years, advances in genetically encoded calcium indicators (GECIs) have promoted a revolution in in vivo functional imaging. Using calcium as a proxy for neuronal activity, these techniques provide a way to monitor the responses of individual cells within large neuronal ensembles to a variety of stimuli in real time. We, and others, have applied these techniques to image the responses of individual geniculate ganglion neurons to taste stimuli applied to the tongues of live anesthetized mice. The geniculate ganglion is comprised of the cell bodies of gustatory neurons innervating the anterior tongue and palate as well as some somatosensory neurons innervating the pinna of the ear. Imaging the taste-evoked responses of individual geniculate ganglion neurons with GCaMP has provided important information about the tuning profiles of these neurons in wild-type mice as well as a way to detect peripheral taste miswiring phenotypes in genetically manipulated mice. Here we demonstrate the surgical procedure to expose the geniculate ganglion, GCaMP fluorescence image acquisition, initial steps for data analysis, and troubleshooting. This technique can be used with transgenically encoded GCaMP, or with AAV-mediated GCaMP expression, and can be modified to image particular genetic subsets of interest (i.e., Cre-mediated GCaMP expression). Overall, in vivo calcium imaging of geniculate ganglion neurons is a powerful technique for monitoring the activity of peripheral gustatory neurons and provides complementary information to more traditional whole-nerve chorda tympani recordings or taste behavior assays.

Here we present how to expose the geniculate ganglion of a live, anesthetized laboratory mouse and how to use calcium imaging to measure the responses of ensembles of these neurons to taste stimuli, allowing for multiple trials with different stimulants. This allows for in depth comparisons of which neurons respond to which tastants.

마우스 의 생체 칼슘 이미징에서 맛 자극에 신경절 신경 반응

Within the last ten years, advances in genetically encoded calcium indicators (GECIs) have promoted a revolution in in vivo functional imaging. Using ...