मस्तिष्क के ऊतकों के जीर्ण Optogenetic उत्तेजना के लिए फाइबर ऑप्टिक आरोपण
Summary
optogenetics के विकास अब ठीक आनुवंशिक रूप से परिभाषित न्यूरॉन्स और सर्किट को प्रोत्साहित करने का मतलब है, दोनों प्रदान करता है<em> इन विट्रो में</em> और<em> Vivo में</em>. यहाँ हम विधानसभा और मस्तिष्क के ऊतकों के जीर्ण photostimulation के लिए ऑप्टिक फाइबर के आरोपण का वर्णन करता है.
Abstract
Elucidating patterns of neuronal connectivity has been a challenge for both clinical and basic neuroscience. Electrophysiology has been the gold standard for analyzing patterns of synaptic connectivity, but paired electrophysiological recordings can be both cumbersome and experimentally limiting. The development of optogenetics has introduced an elegant method to stimulate neurons and circuits, both in vitro1 and in vivo2,3. By exploiting cell-type specific promoter activity to drive opsin expression in discrete neuronal populations, one can precisely stimulate genetically defined neuronal subtypes in distinct circuits4-6. Well described methods to stimulate neurons, including electrical stimulation and/or pharmacological manipulations, are often cell-type indiscriminate, invasive, and can damage surrounding tissues. These limitations could alter normal synaptic function and/or circuit behavior. In addition, due to the nature of the manipulation, the current methods are often acute and terminal. Optogenetics affords the ability to stimulate neurons in a relatively innocuous manner, and in genetically targeted neurons. The majority of studies involving in vivo optogenetics currently use a optical fiber guided through an implanted cannula6,7; however, limitations of this method include damaged brain tissue with repeated insertion of an optical fiber, and potential breakage of the fiber inside the cannula. Given the burgeoning field of optogenetics, a more reliable method of chronic stimulation is necessary to facilitate long-term studies with minimal collateral tissue damage. Here we provide our modified protocol as a video article to complement the method effectively and elegantly described in Sparta et al.8 for the fabrication of a fiber optic implant and its permanent fixation onto the cranium of anesthetized mice, as well as the assembly of the fiber optic coupler connecting the implant to a light source. The implant, connected with optical fibers to a solid-state laser, allows for an efficient method to chronically photostimulate functional neuronal circuitry with less tissue damage9 using small, detachable, tethers. Permanent fixation of the fiber optic implants provides consistent, long-term in vivo optogenetic studies of neuronal circuits in awake, behaving mice10 with minimal tissue damage.
Protocol
Discussion
Optogenetics एक शक्तिशाली नई तकनीक है कि विशिष्ट neuronal उपप्रकारों में अभूतपूर्व नियंत्रण की अनुमति देता है. यह शारीरिक और अस्थायी परिशुद्धता के साथ तंत्रिका सर्किट व्यवस्थित शोषण किया जा सकता है, जबकि एक इलेक्?…
Acknowledgements
हम स्वीकार करते हैं कि इस तकनीक का मूल Sparta एट अल., 2012 द्वारा वर्णित किया गया था और आसानी से हमारी प्रयोगशाला में प्रयोग के लिए अनुकूलित किया गया है के लिए करना चाहते हैं.
Materials
| Name of the Reagent or Equipment | Company | Catalogue # | Comments |
| LC Ferrule Sleeve | Precision Fiber Products (PFP) | SM-CS125S | 1.25 mm ID |
| FC MM Pre-Assembled Connector | PFP | MM-CON2004-2300 | 230 μm Ferrule |
| Miller FOPD-LC Disc | PFP | M1-80754 | For LC ferrules |
| Furcation tubing | PFP | FF9-250 | 900 μm o.d., 250 μm i.d. |
| MM LC Stick Ferrule 1.25 mm | PFP | MM-FER2007C-1270 | 127 μm ID Bore |
| MM LC Stick Ferrule 1.25 mm | PFP | MM-FER2007C-2300 | 230 μm ID Bore |
| Heat-curable epoxy, hardener and resin | PFP | ET-353ND-16OZ | |
| FC/PC and SC/PC Connector Polishing Disk | ThorLabs | D50-FC | For FC ferrules |
| Digital optical power and Energy Meter | ThorLabs | PM100D | Spectrophotometer |
| Polishing Pad | ThorLabs | NRS913 | 9″ x 13″ 50 Durometer |
| Aluminum oxide Lapping (Polishing) Sheets: 0.3, 1, 3, 5 μm grits | ThorLabs | LFG03P, LFG1P, LFG3P, LFG5P | |
| Standard Hard Cladding Multimode Fiber | ThorLabs | BFL37-200 | Low OH, 200 μm Core, 0.37 NA |
| Fiber Stripping Tool | ThorLabs | T10S13 | Clad/Coat: 200 μm / 300 μm |
| SILICA/SILICA Optical Fiber | Polymicro Technologies | FVP100110125 | High -OH, UV Enhanced, 0.22 NA |
| 1×1 Fiberoptic Rotary Joint | doric lenses | FRJ_FC-FC | |
| Mono Fiberoptic Patchcord | doric lenses | MFP_200/230/900-0.37_2m_FC-FC | |
| Heat shrink tubing, 1/8 inch | Allied Electronics | 689-0267 | |
| Heat gun | Allied Electronics | 972-6966 | 250 W; 750-800 °F |
| Cotton tipped applicators | Puritan Medical Products Company | 806-WC | |
| VetBond tissue adhesive | Fischer Scientific | 19-027136 | |
| Flash denture base acrylic | Yates Motloid | ColdPourPowder+Liq | |
| BONN Miniature Iris Scissors | Integra Miltex | 18-1392 | 3-1/2″(8.9cm), straight, 15 mm blades |
| Johns Hopkins Bulldog Clamp | Integra Miltex | 7-290 | 1-1/2″(3.8 cm), curved |
| MEGA-Torque Electric Lab Motor | Vector | EL-S | |
| Panther Burs-Ball #1 | Clarkson Laboratory | 77.1006 | |
| Violet Blue Laser System | CrystaLaser | CK473-050-O | Wavelength: 473 nm |
| Laser Power Supply | CrystaLaser | CL-2005 | |
| Dumont #2 Laminectomy Forceps | Fine Science Tools | 11223-20 | |
| Probe | Fine Science Tools | 10140-02 | |
| 5″Straight Hemostat | Excelta | 35-PH | |
| Vise with weighted base | Altex Electronics | PAN381 |
References
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