scholarly journals Cortical spheroids display oscillatory network dynamics

2021 ◽  
Author(s):  
Jessica L Sevetson ◽  
Brian Theyel ◽  
Diane Hoffman-Kim
Keyword(s):  
Three Dimensional ◽  
Network Activity ◽  
Central Nervous System Function ◽  
Calcium Indicator ◽  
Nervous System Function ◽  
Oscillatory Network ◽  
High Throughput Experiments ◽  
Indicator Dye ◽  
Over Time

Three-dimensional brain cultures can facilitate the study of central nervous system function and disease, and one of the most important components that they present is neuronal activity on a network level. Here we demonstrate network activity in rodent cortical spheroids while maintaining the networks intact in their 3D state. Networks developed by nine days in culture and became more complex over time. To measure network activity, we imaged neurons in rat and mouse spheroids labelled with a calcium indicator dye, and in mouse spheroids expressing GCaMP. Network activity was evident when we electrically stimulated spheroids, was abolished with glutamatergic blockade, and was altered by GABAergic blockade or partial glutamatergic blockade. We quantified correlations and distances between somas with micron-scale spatial resolution. Spheroids seeded at as few as 4,000 cells gave rise to emergent network events, including oscillations. These results are the first demonstration that self-assembled rat and mouse spheroids exhibit network activity consistent with in vivo network events. These results open the door to experiments on neuronal networks that require fewer animals and enable high throughput experiments on network-perturbing alterations in neurons and glia.

scholarly journals Cortical spheroids display oscillatory network dynamics

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Jess Sevetson ◽  
Brian Theyel ◽  
Diane Hoffman-Kim
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neuronal Activity ◽  
Network Dynamics ◽  
Three Dimensional ◽  
System Function ◽  
Central Nervous System Function ◽  
Nervous System Function ◽  
Oscillatory Network

Three-dimensional brain cultures can facilitate the study of central nervous system function and disease, and one of the most important components that they present is neuronal activity on a network...

scholarly journals Small footprint optoelectrodes using ring resonators for passive light localization

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vittorino Lanzio ◽  
Gregory Telian ◽  
Alexander Koshelev ◽  
Paolo Micheletti ◽  
Gianni Presti ◽  
...  
Keyword(s):  
State Of The Art ◽  
Three Dimensional ◽  
Network Activity ◽  
Ring Resonators ◽  
Spatiotemporal Resolution ◽  
Optical Ring Resonators ◽  
Light Localization ◽  
Order Of Magnitude ◽  
Small Footprint

AbstractThe combination of electrophysiology and optogenetics enables the exploration of how the brain operates down to a single neuron and its network activity. Neural probes are in vivo invasive devices that integrate sensors and stimulation sites to record and manipulate neuronal activity with high spatiotemporal resolution. State-of-the-art probes are limited by tradeoffs involving their lateral dimension, number of sensors, and ability to access independent stimulation sites. Here, we realize a highly scalable probe that features three-dimensional integration of small-footprint arrays of sensors and nanophotonic circuits to scale the density of sensors per cross-section by one order of magnitude with respect to state-of-the-art devices. For the first time, we overcome the spatial limit of the nanophotonic circuit by coupling only one waveguide to numerous optical ring resonators as passive nanophotonic switches. With this strategy, we achieve accurate on-demand light localization while avoiding spatially demanding bundles of waveguides and demonstrate the feasibility with a proof-of-concept device and its scalability towards high-resolution and low-damage neural optoelectrodes.

scholarly journals In vivo multiphoton microscopy of cardiomyocyte calcium dynamics in the beating mouse heart

2018 ◽  
Author(s):  
Jason S. Jones ◽  
David M. Small ◽  
Nozomi Nishimura
Keyword(s):  
Action Potentials ◽  
Multiphoton Microscopy ◽  
Three Dimensional ◽  
Heart Beat ◽  
Beating Heart ◽  
Mouse Heart ◽  
Calcium Dynamics ◽  
Intact Mouse ◽  
Calcium Indicator

AbstractWe demonstrated intravital multiphoton microscopy in the beating heart in an intact mouse and optically measured action potentials with GCaMP6f, a genetically-encoded calcium indicator. Images were acquired at 30 fps with spontaneous heart beat and continuously running ventilated breathing. The data were reconstructed into three-dimensional volumes showing tissue structure, displacement, and GCaMP activity in cardiomyocytes as a function of both the cardiac and respiratory cycle.

scholarly journals Lipopolysaccharide-induced neuroinflammation disrupts functional connectivity and community structure in primary cortical microtissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elaina Atherton ◽  
Sophie Brown ◽  
Emily Papiez ◽  
Maria I. Restrepo ◽  
David A. Borton
Keyword(s):  
Community Structure ◽  
Functional Connectivity ◽  
Three Dimensional ◽  
Theory Analysis ◽  
Disease States ◽  
Calcium Indicator ◽  
Graph Theory Analysis

AbstractThree-dimensional (3D) neural microtissues are a powerful in vitro paradigm for studying brain development and disease under controlled conditions, while maintaining many key attributes of the in vivo environment. Here, we used primary cortical microtissues to study the effects of neuroinflammation on neural microcircuits. We demonstrated the use of a genetically encoded calcium indicator combined with a novel live-imaging platform to record spontaneous calcium transients in microtissues from day 14–34 in vitro. We implemented graph theory analysis of calcium activity to characterize underlying functional connectivity and community structure of microcircuits, which are capable of capturing subtle changes in network dynamics during early disease states. We found that microtissues cultured for 34 days displayed functional remodeling of microcircuits and that community structure strengthened over time. Lipopolysaccharide, a neuroinflammatory agent, significantly increased functional connectivity and disrupted community structure 5–9 days after exposure. These microcircuit-level changes have broad implications for the role of neuroinflammation in functional dysregulation of neural networks.

scholarly journals Lipopolysaccharide-induced neuroinflammation disrupts functional connectivity and community structure in primary cortical microtissues

2021 ◽  
Author(s):  
Elaina Atherton ◽  
Sophie Brown ◽  
Emily Papiez ◽  
Maria Isabel Restrepo ◽  
David Allenson Borton
Keyword(s):  
Community Structure ◽  
Functional Connectivity ◽  
Three Dimensional ◽  
Theory Analysis ◽  
Calcium Indicator ◽  
Functional Remodeling ◽  
Graph Theory Analysis

Three-dimensional (3D) neural microtissues are a powerful in vitro paradigm for studying brain development and disease under controlled conditions, while maintaining many key attributes of the in vivo environment. Here, we used primary cortical microtissues to study the effects of neuroinflammation on neural microcircuits. We demonstrated the use of a genetically encoded calcium indicator combined with a novel live-imaging platform to record spontaneous calcium transients in microtissues from day 14-34 in vitro. We implemented graph theory analysis of calcium activity to characterize underlying functional connectivity and community structure of microcircuits, which are capable of capturing subtle changes in network dynamics during early diseases states. We found that microtissues cultured for 34 days displayed functional remodeling of microcircuits and that community structure strengthened over time. Lipopolysaccharide, a neuroinflammatory agent, significantly increased functional connectivity and disrupted community structure 5-9 days after exposure. These microcircuit-level changes have broad implications for the role of neuroinflammation in functional dysregulation of neural networks.

Using Knockout and Transgenic Mice to Study Neurophysiology and Behavior

1998 ◽  
Vol 78 (4) ◽  
pp. 1131-1163 ◽  
Author(s):  
MARINA R. PICCIOTTO ◽  
KEVIN WICKMAN
Keyword(s):  
Transgenic Mice ◽  
Reverse Genetics ◽  
New Technologies ◽  
Detailed Knowledge ◽  
Central Nervous System Function ◽  
Physiological Relevance ◽  
Nervous System Function ◽  
And Behavior ◽  
Mouse Mutagenesis

Picciotto, Marina R., and Kevin Wickman. Using Knockout and Transgenic Mice to Study Neurophysiology and Behavior. Physiol. Rev. 78: 1131–1163, 1998. — Reverse genetics, in which detailed knowledge of a gene of interest permits in vivo modification of its expression or function, provides a powerful method for examining the physiological relevance of any protein. Transgenic and knockout mouse models are particularly useful for studies of complex neurobiological problems. The primary aims of this review are to familiarize the nonspecialist with the techniques and limitations of mouse mutagenesis, to describe new technologies that may overcome these limitations, and to illustrate, using representative examples from the literature, some of the ways in which genetically altered mice have been used to analyze central nervous system function. The goal is to provide the information necessary to evaluate critically studies in which mutant mice have been used to study neurobiological problems.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Three-Dimensional Subcellular Organization of Hepatocytes in Intact Liver: Simultaneous Visualization of Cytoskeletal and Membrane Markers by Confocal Microscopy

1996 ◽  
Vol 54 ◽  
pp. 288-289
Author(s):  
Greg V. Martin ◽  
Ann L. Hubbard
Keyword(s):  
Three Dimensional ◽  
Integral Membrane Proteins ◽  
Polarized Secretion ◽  
Microscope Images ◽  
Computer Aided ◽  
Intracellular Organelles ◽  
Cytoskeletal Elements ◽  
Simultaneous Visualization

The microtubule (MT) cytoskeleton is necessary for many of the polarized functions of hepatocytes. Among the functions dependent on the MT-based cytoskeleton are polarized secretion of proteins, delivery of endocytosed material to lysosomes, and transcytosis of integral plasma membrane (PM) proteins. Although microtubules have been shown to be crucial to the establishment and maintenance of functional and structural polarization in the hepatocyte, little is known about the architecture of the hepatocyte MT cytoskeleton in vivo, particularly with regard to its relationship to PM domains and membranous organelles. Using an in situ extraction technique that preserves both microtubules and cellular membranes, we have developed a protocol for immunofluorescent co-localization of cytoskeletal elements and integral membrane proteins within 20 µm cryosections of fixed rat liver. Computer-aided 3D reconstruction of multi-spectral confocal microscope images was used to visualize the spatial relationships among the MT cytoskeleton, PM domains and intracellular organelles.

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