Removable cranial windows for long-term imaging in awake mice

Goldey, Glenn J.; Roumis, Demetris; Glickfeld, Lindsey L.; Kerlin, Aaron; Reid, R. Clay; Bonin, Vincent; Schafer, Dorothy P.; Andermann, Mark L.

doi:10.1038/nprot.2014.165

Cited by 353 publications

(348 citation statements)

References 19 publications

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“…Walking significantly decreased the rate of complex spikes (CS) in the PCL (0.3 ± 0.4 Hz to 0.04 ± 0.13 Hz, p = 5x10 -5 ). As expected, CS were too rare to quantify in the Oriens interneurons (only one putative CS from all recordings) 19 . Intercellular correlations in subthreshold voltage reflect shared synaptic inputs, an important measure of network architecture that is often not apparent from spike timing alone 24 .…”

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confidence: 51%

All-optical electrophysiology reveals brain-state dependent changes in hippocampal subthreshold dynamics and excitability

Adam

et al. 2018

Preprint

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A technology to record membrane potential from multiple neurons, simultaneously, in behaving animals will have a transformative impact on neuroscience research . Genetically encoded voltage indicators are a promising tool for these purposes, but were so far limited to single-cell recordings with marginal signal to noise ratio (SNR) in vivo [4][5][6] . We developed improved near infrared voltage indicators, high speed microscopes and targeted gene expression schemes which enabled recordings of supra-and subthreshold voltage dynamics from multiple neurons simultaneously in mouse hippocampus, in vivo. The reporters revealed sub-cellular details of back-propagating action potentials, correlations in sub-threshold voltage between multiple cells, and changes in dynamics associated with transitions from resting to locomotion. In combination with optogenetic stimulation, the reporters revealed brain state-dependent changes in neuronal excitability, reflecting the interplay of excitatory and inhibitory synaptic inputs. These tools open the possibility for detailed explorations of network dynamics in the context of behavior. Main textArchaerhodopsin-derived genetically encoded voltage indicators (GEVIs) are excited by red light and emit in the near infrared part of the spectrum, have sub-millisecond response times at physiological temperature, and report neuronal action potentials with a ~40% change in fluorescence brightness [7][8][9] . A transgenic mouse expressing the Arch-based GEVI QuasAr2 and the channelrhodopsin CheRiff (together called 'Optopatch2') enabled optical stimulation and recording in sparsely expressing acute brain slices 4 , but did not attain adequate SNR for voltage imaging in brain in vivo. The primary factors which limited SNR were (a) poor trafficking of QuasAr2 in vivo, leading to intracellular aggregates that contributed to fluorescence background, and (b) high background, due to light scattering, out-of-focus fluorescence, and fluorescence from optically unresolvable neuropil.To address the trafficking challenge, we systematically tested the impacts of trafficking sequences, appended fluorescent proteins, linker sequences, and various point mutations (Methods). We used the Optopatch system 7 to test the SNR for optogenetically induced action potentials first in All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/281618 doi: bioRxiv preprint first posted online Mar. 13, 2018; 2 cultured neurons, and then in acute brain slices (Fig. S1). Incorporation of multiple K ir 2.1 trafficking sequences, a Citrine fluorescent protein fusion (instead of mOrange2), and mutation of a putative ubiquitination site (lysine 171) to arginine, led to a construct that showed high expression and excellent trafficking in vivo, which we called QuasAr3 (Fig. 1). In acute cortical slices, QuasAr2 produced bright intracell...

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supporting

confidence: 51%

All-optical electrophysiology reveals brain-state dependent changes in hippocampal subthreshold dynamics and excitability

Adam

et al. 2018

Preprint

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“…In an open-skull cranial window with a glass cover in rats, a duratomy is required for better visibility due to inflammatory reactions as well as dural regrowth6111216, which makes it difficult to maintain an optically clear window for an extended period of time. To examine the condition of an open-skull chronic window with PDMS, 13 rats subjected to a duratomy procedure were studied for up to 10 weeks after the cranial window implantation.…”

Section: Resultsmentioning

confidence: 99%

A soft, transparent, freely accessible cranial window for chronic imaging and electrophysiology

Heo

Park

Kim

et al. 2016

Sci Rep

117

113

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Chronic in vivo imaging and electrophysiology are important for better understanding of neural functions and circuits. We introduce the new cranial window using soft, penetrable, elastic, and transparent, silicone-based polydimethylsiloxane (PDMS) as a substitute for the skull and dura in both rats and mice. The PDMS can be readily tailored to any size and shape to cover large brain area. Clear and healthy cortical vasculatures were observed up to 15 weeks post-implantation. Real-time hemodynamic responses were successfully monitored during sensory stimulation. Furthermore, the PDMS window allowed for easy insertion of microelectrodes and micropipettes into the cortical tissue for electrophysiological recording and chemical injection at any location without causing any fluid leakage. Longitudinal two-photon microscopic imaging of Cx3Cr1+/− GFP transgenic mice was comparable with imaging via a conventional glass-type cranial window, even immediately following direct intracortical injection. This cranial window will facilitate direct probing and mapping for long-term brain studies.

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“…Further, recording 1-1.5 h after the surgery may not induce inflammation that affects the glycocalyx. To avoid this issue, use of alternative methods of accessing the pial circulation [36,37] should be considered for further studies.…”

Section: Discussionmentioning

confidence: 99%

In vivo Imaging of the Cerebral Endothelial Glycocalyx in Mice

Yoon

Lee²,

Jeong³

2017

J Vasc Res

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Background/Aims: Endothelial glycocalyx refers to the proteoglycan or glycoprotein layer of vessel walls and has critical physiological functions. Cerebral glycocalyx may have additional functions considering the blood-brain barrier and other features. However, the assessment of it has only been performed ex vivo, which includes processes presumably damaging the glycocalyx layer. Here we visualize and characterize the cerebral endothelial glycocalyx in vivo. Methods: We visualized and quantified the cerebral endothelial glycocalyx in vivo under a 2-photon microscope by tagging glycocalyx and vessel lumen with wheat germ agglutinin lectin and dextran, respectively. The radial intensity was analyzed to measure the thickness of the cerebral endothelial glycocalyx in each vessel type. Results: Cerebral arteries and capillaries have an intact endothelial glycocalyx, but veins and venules do not. The thickness of the glycocalyx layer in pial arteries, penetrating arteries, and capillaries was different; however, it was not correlated with the vessel diameter within each vessel type. Conclusion: We characterized the distribution of the cerebral endothelial glycocalyx in vivo. Compared to the results from ex vivo studies, the layer is thicker, indicating that the layer may be damaged in ex vivo systems. We also observed an inhomogeneous cerebral endothelial glycocalyx distribution that might reflect the functional heterogeneity of the vessel type.

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Removable cranial windows for long-term imaging in awake mice

Cited by 353 publications

References 19 publications

All-optical electrophysiology reveals brain-state dependent changes in hippocampal subthreshold dynamics and excitability

All-optical electrophysiology reveals brain-state dependent changes in hippocampal subthreshold dynamics and excitability

A soft, transparent, freely accessible cranial window for chronic imaging and electrophysiology

In vivo Imaging of the Cerebral Endothelial Glycocalyx in Mice

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