En poleret og forstærket tyndt befolket kranie Window for langsigtet Imaging af Mouse Brain
Summary
Vi præsenterer en fremgangsmåde til dannelse af en billeddannende vindue i mus kraniet, der strækker sig millimeter og er stabil i måneder uden inflammation i hjernen. Denne fremgangsmåde er velegnet til langsgående studier af blodgennemstrømning, cellulære dynamik, og celle / vaskulær struktur med to-foton-mikroskopi.
Abstract
In vivo billeddannelse af cortical funktion kræves optisk adgang til hjernen, uden afbrydelse af intrakranial miljøet. Vi præsenterer en fremgangsmåde til dannelse af en poleret og forstærket fortyndet kraniet (porte) vinduet i mus kraniet, som spænder over flere millimeter i diameter og er stabil i måneder. Kraniet fortyndes til 10 til 15 um i tykkelse med en håndholdt boremaskine til at opnå optisk klarhed, og derefter overlejret med cyanoacrylat lim og et dækglas til: 1) tilvejebringe stivhed, 2) inhibering af fornyet knoglevækst og 3) reduktion af lysspredning fra uregelmæssigheder på knogleoverfladen. Da kraniet ikke er overtrådt, er enhver betændelse, der kan påvirke processen ved at blive undersøgt stærkt reduceret. Billeddannelse dybder på op til 250 um under den kortikale overflade kan opnås ved anvendelse af to-foton laser scanning-mikroskopi. Dette vindue er velegnet til at studere cerebral blodgennemstrømning og cellulær funktion i både bedøvede og vågen præparater. Det yderligere giver oplighed for at manipulere celleaktivitet under anvendelse optogenetics eller at afbryde blodstrømmen i målrettede fartøjer ved bestråling af cirkulerende fotosensibilisatorer.
Protocol
Discussion
To-foton billeddannelse gennem et HAVNE vindue kræver transmission gennem den indsnævrede ben og dura, som dæmper laserlyset og tilføjer optiske aberrationer på større dybder 8. Til trods for denne ulempe kan billeddannelse dybder op til 250 um under pial overflade opnås med 900 nm excitation. Større billeddannelse dybder kan i princippet være muligt med længere excitationsbølgelængder 13. En væsentlig fordel ved denne fremgangsmåde er fraværet af kortikale inflammation, der kan eksi…
Declarações
The authors have nothing to disclose.
Acknowledgements
Dette arbejde blev støttet af American Heart Association (Post-ph.d.-stipendium til at kys), og National Institutes of Health (MH085499, EB003832, og OD006831 til DK). Vi takker Beth Friedman og Pablo Blinder for kommentarer til manuskriptet.
Materials
| Agent | Route of delivery | Dose for mouse | Duration | Notes | Source | Ref Ref |
| Pentobarbital (Nembutal) | IP | 90 μg/g | 15-60 min | Narrow safety margin. Work up to proper dose of anesthesia slowly. Supplement 10 % of induction dose as required. | 036093; Butler Schein | 7 |
| Ketamine (Ketaset) mixed with Xylazine (Anased) | IP | 60 μg/g (K)
10 μg/g (X) (mix in same syringe) |
20-30 min | Xylazine is co-injected as a muscle relaxant and analgesic. Supplement only Ketamine at 50% of induction dose as required. | (K) 010177, (X) 033198; Butler Schein | 7 |
| Isoflurane (Isothesia) | Inhalation | 4% mean alveolar concentration (MAC) for induction; 1-2% MAC for maintenance | 4-6 h. | Provided in mixture of 70% oxygen and 30% nitrous oxide. Prolonged anesthesia leads to slow recovery. | 029403; Butler Schein | 26 |
Table 1. Suggested anesthetic agents for survival studies.
| ITEM | COMPANY | CATALOG # / MODEL |
| Betadine | Butler Schein | 6906950 |
| Buprenorphine (Buprenex) | Butler Schein | 031919 |
| Fluorescein isothiocyanate dextran, 2 MDa molecular weight | Sigma | FD2000S |
| Isopropyl alcohol | Fisher | AC42383-0010 |
| Lactated Ringer’s Solution | Butler Schein | 009846; |
| Lidocaine solution, 2 % (v/v) | Butler Schein | 002468 |
| Saline | Butler Schein | 009861 |
| Surgical Milk | Butler Schein | 014325 |
| Texas Red dextran, 70 kDa molecular weight | Invitrogen | D1864 |
| Maxizyme | Butler Schein | 035646 |
| DISPOSABLES | ||
| Carbide burrs, 1/2 mm tip size | Fine Science Tools | 19007-05 |
| Cottoned tip applicators | Fisher Scientific | 23-400-100 |
| Cover Glass, no. 0 thickness | Thomas Scientific | 6661B40 |
| Cyanoacrylate glue | ND Industries | 31428 H04308 |
| Gas duster | Newegg | N82E16848043429 |
| Grip cement powder | Dentsply | 675571 |
| Grip cement solvent | Dentsply | 675572 |
| Insulin syringe, 0.3 mL volume with 29.5 gauge needle | Butler Schein | 018384 |
| Nut and bolt to secure the head | Digikey | Nut, H723-ND; bolt, R2-56X1/4-ND |
| Opthalmic ointment | Butler Schein | 039886 |
| Scalpel blades | Fisher Scientific | 12-460-448 |
| Screws, self-tapping #000 | J.I. Morris Company | FF000CE125 |
| Silicone aquarium sealant | Perfecto Manufacturing | 31001 |
| Tin oxide powder | Mama’s Minerals | EQT-TINOX |
| EQUIPMENT | ||
| Glass scribe | Fisher Scientific | 08-675 |
| Dissecting microscope | Carl Zeiss | OPMI-1 FC |
| Electric powered drill | Foredom or Osada | K.1020 (Foredom) or EXL-M40 (Osada) |
| Electrical razor | Wahl | Series 8900 |
| Forceps, Dumont no. 55 | Fine Science Tools | 11255-20 |
| Feedback regulated heat pad | FHC | 40-90-8 (rectal thermistor, 40-90-5D-02; heat pad, 40-90-2-07) |
| Isoflurane vaporizer | Ohmeda | IsoTec4 |
| Pulse oximeter | Starr Life Sciences | MouseOx |
| Screwdriver, miniature | Garret Wade | 26B09.01 |
| Stereotaxic frame | Kopf Instruments | Model 900 (with mouse anesthesia mask and non-rupture ear bars) |
| Surgical scissors, blunt end | Fine Science Tools | 14078-10 |
| Ultrasonic cleaner | Fisher Scientific | 15-335-30 |
Table 2. List of specific reagents, disposables and equipment.
Referências
- Cetin, A. Stereotaxic gene delivery in the rodent brain. Nature Protocols. 1, 3166-3173 (2006).
- Kleinfeld, D., Delaney, K. R. Distributed representation of vibrissa movement in the upper layers of somatosensory cortex revealed with voltage sensitive dyes. Journal of Comparative Neurology. 375, 89-108 (1996).
- Driscoll, J. D., Yuste, R. Quantitative two-photon imaging of blood flow in cortex. Imaging in Neuroscience and Development. , 927-937 (2011).
- Drew, P. J., Shih, A. Y., Kleinfeld, D. Fluctuating and sensory-induced vasodynamics in rodent cortex extends arteriole capacity. Proceedings of the National Academy of Sciences U.S.A. 108, 8473-8473 (2011).
- Mostany, R., Portera-Cailliau, C. A Method for 2-Photon Imaging of Blood Flow in the Neocortex through a Cranial Window. J. Vis. Exp. (12), e678-e678 (2008).
- Zhang, S. Rapid reversible changes in dendritic spine structure in vivo gated by the degree of ischemia. Journal of Neuroscience. 25, 5333-5338 (2005).
- Takano, T. Astrocyte-mediated control of cerebral blood flow. Nature Neuroscience. 9, 260-267 (2006).
- Drew, P. J. Chronic optical access through a polished and reinforced thinned skull. Nature Methods. 7, 981-984 (2010).
- Marker, D. F. A thin-skull window technique for chronic two-photon in vivo imaging of murine microglia in models of neuroinflammation. Journal of Visualized Experiments. (43), e2059-e2059 (2010).
- Feng, G. Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP. Neuron. 28, 41-51 (2000).
- Martin, C. Investigating neural-hemodynamic coupling and the hemodynamic response function in the awake rat. Neuroimage. 32, 33-48 (2006).
- Shih, A. Y. Two-photon microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain. Journal of Cerebral Blood Flow and Metabolism. , (2011).
- Kobat, D. Deep tissue multiphoton microscopy using longer wavelength excitation. Optics Express. 17, 13354-13364 (2009).
- Holtmaat, A. high-resolution imaging in the mouse neocortex through a chronic cranial window. Nature Protocols. 4, 1128-1144 (2009).
- Xu, H. T. Choice of cranial window type for in vivo imaging affects dendritic spine turnover in the cortex. Nature Neuroscience. 10, 549-551 (2007).
- Nimmerjahn, A., Kirchhoff, F., Helmchen, F. Resting microglial cells are highly dynamic surveillants of brain parenchyma in vivo. Science. 308, 1314-1318 (2005).
- Davalos, D. ATP mediates rapid microglial response to local brain injury in vivo. Nature Neuroscience. 8, 752-758 (2005).
- Ascenzi, A., Fabry, C. Technique for dissection and measurement of refractive index of osteons. The Journal of Biophysical and Biochemical Cytology. 6, 139-142 (1959).
- Stosiek, C. In vivo two-photon calcium imaging of neuronal networks. Proceedings of the National Academy of Sciences U.S.A. 100, 7319-7324 (2003).
- Grinvald, A. Functional architecture of cortex revealed by optical imaging of intrinsic signals. Nature. 324, 361-364 (1986).
- Dunn, A. K. Dynamic imaging of cerebral blood flow using laser speckle. Journal of Cerebral Blood Flow & Metabolism. 21, 195-201 (2001).
- Villringer, A. Capillary perfusion of the rat brain cortex: An in vivo confocal microscopy study. Circulation Research. 75, 55-62 (1994).
- Denk, W., Strickler, J. H., Webb, W. W. Two-photon laser scanning fluorescence microscopy. Science. 248, 73-76 (1990).
- Srinivasan, V. J. Optical coherence tomography for the quantitative study of cerebrovascular physiology. Journal of Cerebral Blood Flow & Metabolism. 31, 1339-1345 (2011).
- Hu, S., Wang, L. V. Photoacoustic imaging and characterization of the microvasculature. Journal of Biomedical Optics. 15, 011101-011101 (2010).
- Flecknell, P. A. . Laboratory animal anesthesia. , (1987).
