Chronic Imaging of Mouse Visual Cortex Using a Thinned-skull Preparation
Summary
In this video and supplemental material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation.
Abstract
In vivo imaging using two-photon laser scanning microscopy (2PLSM) allows the study of living cells and neuronal processes in the intact brain. The technique presented here allows the imaging of the same area of the brain at several time points (chronic imaging) with microscopic resolution allowing the tracking of dendritic spines which are the small structures that represent the majority of postsynaptic excitatory sites in the CNS. The ability to clearly resolve fine cortical structures over several time points has many advantages, specifically in the study of brain plasticity in which morphological changes at synapses and circuit remodeling may help explain underlying mechanisms. In this video and supplementary material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation. The thinned-skull preparation is a minimally invasive approach, which avoids potential damage to the dura and/or cortex, thus reducing the onset of an inflammatory response. When this protocol is performed correctly, it is possible to clearly monitor changes in dendritic spine characteristics in the intact brain over a prolonged period of time.
Protocol
Discussion
Chronic imaging using two-photon microscopy is becoming an increasingly popular technique to study morphological changes triggered during plasticity2-5. Here we demonstrate a thinned-skull preparation to follow identified dendritic spines in the intact mouse brain on different imaging days. In this protocol, the skull is left intact, causing minimal damage to the cortex and resulting in very low levels of neuroinflammation which may alter brain function6. This allows the animal to be imaged immedia…
Disclosures
The authors have nothing to disclose.
Acknowledgements
This work was supported by Burroughs Wellcome Career Award in the Biomedical Sciences (A.K.M), The Whitehall Foundation Research Grant (A.K.M), Sloan Foundation Fellowship (A.K.M), NIH EY019277 (A.K.M), and an NEI funded, Vision Training Grant, EY013319 (E.A.K.).
Materials
| Material Name | Type | Company | Catalogue Number | Comment |
|---|---|---|---|---|
| Fentanyl Citrate | In-house pharmacy | Fentanyl Cocktail: Anesthesic Cocktail; IP Dose: 0.0125 ml/g Final cocktail conc.: 0.05 mg/kg |
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| Medetomindine Hydrochloride | In-house pharmacy | Fentanyl Cocktail: Anesthesic Cocktail; IP Dose: 0.0125 ml/g Final cocktail conc.: 0.05 mg/kg |
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| Midazolam HCL | In-house pharmacy | Fentanyl Cocktail: Anesthesic Cocktail; IP Dose: 0.0125 ml/g Final cocktail conc.: 0.05 mg/kg |
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| 2,2,2-tribromoethanol | Avertin Cocktail: Anesthetic; IP Dose: 0.0075 cc/ g Final cocktail conc.: 1% |
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| 2-methyl-2-butanol (Final concentration: 0.775%) | Avertin Cocktail: Anesthetic; IP Dose: 0.0075 cc/ g Final cocktail conc.: .775% |
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| TC-1000 Temp. Control System for Mice | CWE, Inc. | TC-1000 Mouse | Body Temp. Regulation | |
| Toberadex | In-house pharmacy | Eye Ointment | ||
| 10% Ferric Chloride | Ricca Chemical, Inc. | 3120-32 | Thin-skull preparation | |
| Microsurgical Blade | Sable Industries | S-6400 | Thin-skull preparation | |
| Cyanoacrylate 404,401 | Loctite | P/N 46551 | Thin-skull preparation | |
| Cyanoacrylate 401 | Loctite | P/N 40140 | Thin-skull preparation | |
| Zip Kicker Glue Accelerator | Pacer Technology | PT-29 | Thin-skull preparation | |
| Micro Drill Steel Burrs 0.7mm tip diameter | Fine Science Tools | 19008-07 | Thin-skull preparation | |
| Microtorque Control Box and Tech2000 Handpiece | Ram Products, Inc. | TECH2000ON/OFF | Thin-skull preparation | |
| #6-0 (0.7 metric ) silk suture | Ethicon | K8894H | Taper C-1 | |
| Eye Dressing Forceps, 10cm, tip width 0.5mm, curved | Surgical Tools | Fine Science Tools | 11152-10 | |
| Extra Fine Bonn Scissors, 8.5cm, straight tip, cutting edge 13mm | Surgical Tools | Fine Science Tools | 14084-08 | |
| Standard Pattern Forceps, straight, 2.5mmx1.35mmtip, 12cm | Surgical Tools | Fine Science Tools | 11000-12 |
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