Imaging extracellular potassium dynamics in brain tissue using a potassium-sensitive nanosensor.
Details
State: Public
Version: Final published version
Serval ID
serval:BIB_E244B7407F45
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Imaging extracellular potassium dynamics in brain tissue using a potassium-sensitive nanosensor.
Journal
Neurophotonics
ISSN
2329-423X (Print)
ISSN-L
2329-423X
Publication state
Published
Issued date
2017
Peer-reviewed
Oui
Volume
4
Number
1
Pages
015002
Language
english
Abstract
Neuronal activity results in the release of [Formula: see text] into the extracellular space (ECS). Classically, measurements of extracellular [Formula: see text] ([Formula: see text]) are carried out using [Formula: see text]-sensitive microelectrodes, which provide a single point measurement with undefined spatial resolution. An imaging approach would enable the spatiotemporal mapping of [Formula: see text]. Here, we report on the design and characterization of a fluorescence imaging-based [Formula: see text]-sensitive nanosensor for the ECS based on dendrimer nanotechnology. Spectral characterization, sensitivity, and selectivity of the nanosensor were assessed by spectrofluorimetry, as well as in both wide-field and two-photon microscopy settings, demonstrating the nanosensor efficacy over the physiologically relevant ion concentration range. Spatial and temporal kinetics of the nanosensor responses were assessed using a localized iontophoretic [Formula: see text] application on a two-photon imaging setup. Using acute mouse brain slices, we demonstrate that the nanosensor is retained in the ECS for extended periods of time. In addition, we present a ratiometric version of the nanosensor, validate its sensitivity in brain tissue in response to elicited neuronal activity and correlate the responses to the extracellular field potential. Together, this study demonstrates the efficacy of the [Formula: see text]-sensitive nanosensor approach and validates the possibility of creating multimodal nanosensors.
Keywords
extracellular space, fluorescence microscopy, fluorescent indicator, nanotechnology, potassium, potassium buffering, two-photon imaging
Pubmed
Web of science
Open Access
Yes
Create date
28/02/2017 20:08
Last modification date
20/08/2019 17:06