scholarly journals Expression of c-Fos and Arc in hippocampal region CA1 marks neurons that exhibit learning-related activity changes

2019 ◽  
Author(s):  
David Mahringer ◽  
Anders V. Petersen ◽  
Aris Fiser ◽  
Hiroyuki Okuno ◽  
Haruhiko Bito ◽  
...  
Keyword(s):  
Neural Activity ◽  
Choice Task ◽  
Activity Levels ◽  
Hippocampal Region ◽  
Related Activity ◽  
Expression Levels ◽  
Two Photon ◽  
Calcium Indicator ◽  
Forced Choice Task

Immediate early genes (IEGs) are transcribed in response to neural activity and necessary for many forms of plasticity. However, the dynamics of their expression during learning, as well as their relationship to neural activity, remain unclear. Here we used two-photon imaging in transgenic mice that express a GFP-tagged variant of Arc or c-Fos and a red-shifted calcium indicator to measure learning-related changes in IEG expression levels and neural activity in hippocampal region CA1 as mice learned to perform a two-alternative forced choice task. Neural activity levels correlated positively with IEG expression levelsin vivo. In addition, we found that with learning, a subset of neurons in CA1 increased their responses to the reward-predicting cue, and IEG expression levels early in learning were selectively increased in neurons that would exhibit the strongest learning-related changes. Our findings are consistent with an interpretation of IEG expression levels as markers for experience dependent plasticity.

scholarly journals Dual-color volumetric imaging of neural activity of cortical columns

2018 ◽  
Author(s):  
Shuting Han ◽  
Weijian Yang ◽  
Rafael Yuste
Keyword(s):  
Neural Activity ◽  
High Speed ◽  
Neural Circuits ◽  
Emergent Properties ◽  
Spatiotemporal Resolution ◽  
Population Activity ◽  
Volumetric Imaging ◽  
Two Photon ◽  
Dual Color

To capture the emergent properties of neural circuits, high-speed volumetric imaging of neural activity at cellular resolution is desirable. But while conventional two-photon calcium imaging is a powerful tool to study population activity in vivo, it is restrained to two-dimensional planes. Expanding it to 3D while maintaining high spatiotemporal resolution appears necessary. Here, we developed a two-photon microscope with dual-color laser excitation that can image neural activity in a 3D volume. We imaged the neuronal activity of primary visual cortex from awake mice, spanning from L2 to L5 with 10 planes, at a rate of 10 vol/sec, and demonstrated volumetric imaging of L1 long-range PFC projections and L2/3 somatas. Using this method, we map visually-evoked neuronal ensembles in 3D, finding a lack of columnar structure in orientation responses and revealing functional correlations between cortical layers which differ from trial to trial and are missed in sequential imaging. We also reveal functional interactions between presynaptic L1 axons and postsynaptic L2/3 neurons. Volumetric two-photon imaging appears an ideal method for functional connectomics of neural circuits.

scholarly journals A distributed neocortical action map associated with reach-to-grasp

2020 ◽  
Author(s):  
Eros Quarta ◽  
Alessandro Scaglione ◽  
Jessica Lucchesi ◽  
Leonardo Sacconi ◽  
Anna Letizia Allegra Mascaro ◽  
...  
Keyword(s):  
Motor Control ◽  
Neural Activity ◽  
Wide Field ◽  
Activity Levels ◽  
Large Network ◽  
Reach To Grasp ◽  
Neural Repair ◽  
Neocortical Dynamics ◽  
Motor Areas

ABSTRACTReach-to-Grasp (RtG) is known to be dependent upon neocortical circuits and extensive research has provided insights into how selected neocortical areas contribute to control dexterous movements. Surprisingly, little infor-mation is available on the global neocortical computations underlying RtG in the mouse. Here, we characterized, employing fluorescence wide-field cal-cium imaging, the neocortex-wide dynamics from mice engaging in a RtG task. We demonstrate that, beyond canonical motor regions, several areas, such as the visual and the retrosplenial cortices, also increase their activ-ity levels during successful RtGs. Intriguingly, homologous regions across the ipsilateral hemisphere are also involved. Functional connectivity among areas increases transiently from rest to planning, and decreases during move-ment. Two anti-correlated neocortical networks emerged during movement. At variance, neural activity levels scale linearly with kinematics measures of successful RtGs in secondary motor areas. Our findings establish the coex-istence of distributed and localized neocortical dynamics for efficient control of complex movements.SIGNIFICANCE STATEMENTIn mammals, including humans, the cerebral cortex is known to be critical for the correct execution of dexterous movements. Despite the importance of the mouse for elucidating the neural circuitry for motor control, its neocortex-wide dynamics during RtG are largely unexplored. We used in-vivo fluores-cence microscopy to characterize the neural activity across the neocortex as mice performed a reach-to-grasp task. We show that for such complex movements, a large network of neocortical areas gets involved, while movement kinematics correlates with neural activity in secondary motor areas. These findings indicate the coexistence, at the mesoscale level, of distributed and localized neocortical dynamics for the execution of fine movements. This study offers a novel view on the neocortical correlates of motor control, with potential implications for neural repair.

scholarly journals Genetic dissection of neuropeptide cell biology at high and low activity in a defined sensory neuron

2018 ◽  
Vol 115 (29) ◽  
pp. E6890-E6899 ◽  
Author(s):  
Patrick Laurent ◽  
QueeLim Ch’ng ◽  
Maëlle Jospin ◽  
Changchun Chen ◽  
Ramiro Lorenzo ◽  
...  
Keyword(s):  
Sensory Neuron ◽  
Neural Activity ◽  
Cell Biology ◽  
De Novo ◽  
Synaptic Activity ◽  
Activity Levels ◽  
Genetic Dissection ◽  
Clustering Methods ◽  
Mutant Phenotypes

Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Unlike synaptic vesicles, which can be recycled and refilled close to release sites, DCVs must be replenished by de novo synthesis in the cell body. Here, we dissect DCV cell biology in vivo in a Caenorhabditis elegans sensory neuron whose tonic activity we can control using a natural stimulus. We express fluorescently tagged neuropeptides in the neuron and define parameters that describe their subcellular distribution. We measure these parameters at high and low neural activity in 187 mutants defective in proteins implicated in membrane traffic, neuroendocrine secretion, and neuronal or synaptic activity. Using unsupervised hierarchical clustering methods, we analyze these data and identify 62 groups of genes with similar mutant phenotypes. We explore the function of a subset of these groups. We recapitulate many previous findings, validating our paradigm. We uncover a large battery of proteins involved in recycling DCV membrane proteins, something hitherto poorly explored. We show that the unfolded protein response promotes DCV production, which may contribute to intertissue communication of stress. We also find evidence that different mechanisms of priming and exocytosis may operate at high and low neural activity. Our work provides a defined framework to study DCV biology at different neural activity levels.

scholarly journals Precise, 3-D optogenetic control of the diameter of single arterioles

2021 ◽  
Author(s):  
Philip J. O’Herron ◽  
David A. Hartmann ◽  
Kun Xie ◽  
Prakash Kara ◽  
Andy Y. Shih
Keyword(s):  
Blood Flow ◽  
Neural Activity ◽  
Light Modulator ◽  
Spatiotemporal Resolution ◽  
Two Photon ◽  
Light Pulses ◽  
All Optical ◽  
Health And Disease ◽  
And Control

AbstractModulation of brain arteriole diameter is critical for maintenance of cerebral blood pressure and control of hyperemia during regional neural activity. However, studies of hemodynamic function in health and disease have lacked a method to control and monitor blood flow with high spatiotemporal resolution. Here, we describe a new all-optical approach to precisely control and monitor arteriolar contractility in vivo using combined two-photon optogenetics and imaging. The expression of the excitatory opsin, ReaChR, in vascular smooth muscle cells enabled rapid and repeated vasoconstriction following brief light pulses. Targeted two-photon activation of ReaCHR using a spatial light modulator (SLM) produced highly localized constrictions when targeted to individual arteries within the neocortex. We demonstrate the utility of this method for examining arteriole contractile dynamics and creating transient blood flow reductions. Additionally, we show that optogenetic constriction can offset or completely block sensory stimulus evoked vasodilation, providing a valuable tool to dissociate blood flow changes from neural activity.

scholarly journals Single-trial neural dynamics are dominated by richly varied movements

2018 ◽  
Author(s):  
Simon Musall ◽  
Matthew T. Kaufman ◽  
Ashley L. Juavinett ◽  
Steven Gluf ◽  
Anne K. Churchland
Keyword(s):  
Neural Activity ◽  
Neural Dynamics ◽  
Specific Task ◽  
Single Trial ◽  
Related Activity ◽  
Two Photon ◽  
Photon Imaging ◽  
Two Photon Imaging

When experts are immersed in a task, do their brains prioritize task-related activity? Most efforts to understand neural activity during well-learned tasks focus on cognitive computations and specific task-related movements. We wondered whether task-performing animals explore a broader movement landscape, and how this impacts neural activity. We characterized movements using video and other sensors and measured neural activity using widefield and two-photon imaging. Cortex-wide activity was dominated by movements, especially uninstructed movements, reflecting unknown priorities of the animal. Some uninstructed movements were aligned to trial events. Accounting for them revealed that neurons with similar trial-averaged activity often reflected utterly different combinations of cognitive and movement variables. Other movements occurred idiosyncratically, accounting for trial-by-trial fluctuations that are often considered “noise”. This held true for extracellular Neuropixels recordings in cortical and subcortical areas. Our observations argue that animals execute expert decisions while performing richly varied, uninstructed movements that profoundly shape neural activity.

scholarly journals Kilohertz two-photon fluorescence microscopy imaging of neural activity in vivo

2020 ◽  
Vol 17 (3) ◽  
pp. 287-290 ◽  
Author(s):  
Jianglai Wu ◽  
Yajie Liang ◽  
Shuo Chen ◽  
Ching-Lung Hsu ◽  
Mariya Chavarha ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Neural Activity ◽  
Microscopy Imaging ◽  
Two Photon ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

scholarly journals Novel Genetically Encoded Bright Positive Calcium Indicator NCaMP7 Based on the mNeonGreen Fluorescent Protein

2020 ◽  
Vol 21 (5) ◽  
pp. 1644 ◽  
Author(s):  
Oksana M. Subach ◽  
Vladimir P. Sotskov ◽  
Viktor V. Plusnin ◽  
Anna M. Gruzdeva ◽  
Natalia V. Barykina ◽  
...  
Keyword(s):  
Calcium Ions ◽  
Fluorescent Protein ◽  
Fast Response ◽  
Two Photon ◽  
Calcium Indicator ◽  
Peptide Pair ◽  
Calcium Indicators ◽  
Green Fluorescent

Green fluorescent genetically encoded calcium indicators (GECIs) are the most popular tool for visualization of calcium dynamics in vivo. However, most of them are based on the EGFP protein and have similar molecular brightnesses. The NTnC indicator, which is composed of the mNeonGreen fluorescent protein with the insertion of troponin C, has higher brightness as compared to EGFP-based GECIs, but shows a limited inverted response with an ΔF/F of 1. By insertion of a calmodulin/M13-peptide pair into the mNeonGreen protein, we developed a green GECI called NCaMP7. In vitro, NCaMP7 showed positive response with an ΔF/F of 27 and high affinity (Kd of 125 nM) to calcium ions. NCaMP7 demonstrated a 1.7-fold higher brightness and similar calcium-association/dissociation dynamics compared to the standard GCaMP6s GECI in vitro. According to fluorescence recovery after photobleaching (FRAP) experiments, the NCaMP7 design partially prevented interactions of NCaMP7 with the intracellular environment. The NCaMP7 crystal structure was obtained at 1.75 Å resolution to uncover the molecular basis of its calcium ions sensitivity. The NCaMP7 indicator retained a high and fast response when expressed in cultured HeLa and neuronal cells. Finally, we successfully utilized the NCaMP7 indicator for in vivo visualization of grating-evoked and place-dependent neuronal activity in the visual cortex and the hippocampus of mice using a two-photon microscope and an NVista miniscope, respectively.

scholarly journals Adrenergic inhibition facilitates normalization of extracellular potassium after cortical spreading depolarization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiromu Monai ◽  
Shinnosuke Koketsu ◽  
Yoshiaki Shinohara ◽  
Takatoshi Ueki ◽  
Peter Kusk ◽  
...  
Keyword(s):  
Neural Activity ◽  
Adrenergic Receptors ◽  
Mechanistic Study ◽  
Extracellular Potassium ◽  
Neuroprotective Effects ◽  
Extracellular Potassium Concentration ◽  
Two Photon ◽  
Spreading Depolarization ◽  
Spontaneous Neural Activity

AbstractCortical spreading depolarization (CSD) is a propagating wave of tissue depolarization characterized by a large increase of extracellular potassium concentration and prolonged subsequent electrical silencing of neurons. Waves of CSD arise spontaneously in various acute neurological settings, including migraine aura and ischemic stroke. Recently, we have reported that pan-inhibition of adrenergic receptors (AdRs) facilitates the normalization of extracellular potassium after acute photothrombotic stroke in mice. Here, we have extended that mechanistic study to ask whether AdR antagonists also modify the dynamics of KCl-induced CSD and post-CSD recovery in vivo. Spontaneous neural activity and KCl-induced CSD were visualized by cortex-wide transcranial Ca2+ imaging in G-CaMP7 transgenic mice. AdR antagonism decreased the recurrence of CSD waves and accelerated the post-CSD recovery of neural activity. Two-photon imaging revealed that astrocytes exhibited aberrant Ca2+ signaling after passage of the CSD wave. This astrocytic Ca2+ activity was diminished by the AdR antagonists. Furthermore, AdR pan-antagonism facilitated the normalization of the extracellular potassium level after CSD, which paralleled the recovery of neural activity. These observations add support to the proposal that neuroprotective effects of AdR pan-antagonism arise from accelerated normalization of extracellular K+ levels in the setting of acute brain injury.

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