يوضح هذا البروتوكول كيفية تنفيذ خلية كاملة تسجيل المشبك التصحيح على الخلايا العصبية للشبكية من إعداد شقة جبل.
شبكية العين الثدييات هي نسيج الطبقات تتألف من أنواع الخلايا العصبية متعددة. لفهم كيفية الإشارات البصرية يتم معالجتها داخل الشبكة متشابك معقد لها، وتستخدم التسجيلات الكهربية في كثير من الأحيان إلى دراسة الروابط بين الخلايا العصبية الفردية. لقد الأمثل لإعداد جبل مسطح لتسجيل المشبك التصحيح من الخلايا العصبية ملحوظ وراثيا في كل العمالي (طبقة الخلايا العقدية) والقائمة العراقية الوطنية (طبقة النووية الداخلية) من شبكية العين الماوس. تسجيل الخلايا العصبية INL في يتصاعد مسطحة ويحظي على شرائح ليتم الحفاظ على الاتصالات الرأسية والجانبية في تكوين السابق، والسماح الدوائر الشبكية مع مكونات جانبية كبيرة لدراستها. وقد استخدمنا هذا الإجراء لمقارنة الاستجابات من الخلايا العصبية المرآة شراكة في شبكية العين مثل خلايا عديم الاستطالات النجمي كوليني (الحويصلات).
As an easily accessible part of the central nervous system, the retina has for decades been a useful model in neuroscience studies. Genetic marking of neurons has allowed detailed characterization of synaptic connections in the retina. With many methodologies available to examine function and morphology of retinal neurons, the patch clamp recording technique has been instrumental in our current understanding of vertically transmitted signals in the retina. These signals are originated from photon absorption in photoreceptors and sent to brain visual centers through spiking of retinal ganglion cells (RGCs). Despite a large body of knowledge accumulated thus far, neural diversity in vascularized mammalian retina remains unsolved and obstructs the full appreciation of retinal circuits that subserve normal vision. This is in part because most recordings were performed on retinal slices to trade lateral circuit integrity for access to more proximal retinal neurons1-3. To gain a comprehensive picture on how retina computes visual signals, it is thus desirable to record neurons in flat-mounts wherein lateral connections, large and small, may be better preserved.
When synaptic transmission from photoreceptors to bipolar cells is interrupted due to a defective metabotropic glutamate receptor 6 (mGluR6) signaling pathway in depolarizing bipolar cells4-6 or simply as the result of photoreceptor loss in degenerated retinas7-10, many RGCs exhibit oscillatory activities. These oscillations originate from multiple sources, however the one involving gap junction coupling between AII amacrine cells (AII-ACs) and depolarizing cone bipolar cells (DCBCs) has received the most attention and hence is best understood1,7,11. We have found another source, which persists under pharmacological blockade of the aforementioned AII-AC/DCBC network and drives oscillation of OFF-type SACs in RhoΔCTA and Nob mice with deafferentated retinas7,8,12. Here we detail our protocol of preparing retinal flat-mounts for INL neuron recording. This approach uses commercial mouse lines (Jax stock no. 006410 and 007905) to mark cholinergic retinal neurons by fluorescent protein (tdTomato) expression that is identifiable under a fluorescent microscope equipped with contrast enhancing optics. Some experimental results acquired through this approach have been previously reported4,5,7,13.
وقد سجلت العديد من المعامل من الخلايا العصبية العمالي في الشقة جبل إعداد 15-18، ولكن إجراءاتنا السماح تسجيل من الخلايا العصبية INL. ونحن نؤكد هنا العديد من الخطوات التي تعتبر بالغة الأهمية للتسجيلات روتينية ناجحة.
نضارة والتس?…
The authors have nothing to disclose.
We thank Joung Jang and Xin Guan for technical assistance. We thank Dr. Rory McQuiston of Virginia Commonwealth University for setting up our first patch clamp rig and advices on experimental procedures. We thank Dr. Samuel Wu for suggestions on voltage clamp recording. The work is supported by NIH grants EY013811, EY022228 and a vision core grant EY002520. C-KC is the Alice R. McPherson Retina Research Foundation Endowed Chair at the Baylor College of Medicine.
Fixed-stage fluorescent microscope with DIC | Olympus | BX51-WI | |
Micromanipulators | Sutter | MP-225 | |
Patch clamp amplifier | A-M System | AM2400 | |
AD converter | National Instrument | NI-USB-6221 | |
Heater controller | Warner Instrument | TC-324B | |
Inline heater | Warner Instrument | SC-20 | |
Peristaltic pump | Rainin | Dynamax | |
pipette puller | Sutter Instrument | P-1000 | |
Glass tube with filament | King Precision Glass | Customized | |
Stimulator | A.M.P.I. | Master-8 | |
Biocytin | Sigma | B4261 | |
NaCl | Sigma | S6191 | |
KCl | Sigma | P5405 | |
NaHCO3 | Fisher | BP328-1 | |
Na2HPO4 | Sigma | S0876 | |
NaH2PO4 | Sigma | S5011 | |
CaCl2 | Sigma | C5670 | |
MgSO4 | Sigma | M1880 | |
D-glucose | Sigma | G6152 | |
K-gluconate | Sigma | G4500 | |
ATP-Mg | Sigma | A9187 | |
Li-GTP | Sigma | G5884 | |
EGTA | Sigma | E0396 | |
HEPES | Sigma | H4034 | |
KOH | Sigma | P5958 | |
Cs-methanesulfonate | Sigma | C1426 | |
CsOH | Sigma | 232041 | |
Syringer filter | Nalgene | 171 | |
1 ml syring | Rainin | 17013002 | |
10 ul pipette tip | Genesee Scientific | 24-130RL | |
Streptavidin-488 | ThermoFisher | S-11223 | |
10X PBS | Lonza | 17-517Q |