Cre-Dependent Anterograde Transsynaptic Labeling and Functional Imaging in Zebrafish Using VSV With Reduced Cytotoxicity

The small size and translucency of larval zebrafish (Danio rerio) have made it a unique experimental system to investigate whole-brain neural circuit structure and function. Still, the connectivity patterns between most neuronal types remain mostly unknown. This gap in knowledge underscores the critical need for effective neural circuit mapping tools, especially ones that can integrate structural and functional analyses. To address this, we previously developed a vesicular stomatitis virus (VSV) based approach called Tracer with Restricted Anterograde Spread (TRAS). TRAS utilizes lentivirus to complement replication-incompetent VSV (VSVΔG) to allow restricted (monosynaptic) anterograde labeling from projection neurons to their target cells in the brain. Here, we report the second generation of TRAS (TRAS-M51R), which utilizes a mutant variant of VSVΔG [VSV(M51R)ΔG] with reduced cytotoxicity. Within the primary visual pathway, we found that TRAS-M51R significantly improved long-term viability of transsynaptic labeling (compared to TRAS) while maintaining anterograde spread activity. By using Cre-expressing VSV(M51R)ΔG, TRAS-M51R could selectively label excitatory (vglut2a positive) and inhibitory (gad1b positive) retinorecipient neurons. We further show that these labeled excitatory and inhibitory retinorecipient neurons retained neuronal excitability upon visual stimulation at 5–8 days post fertilization (2–5 days post-infection). Together, these findings show that TRAS-M51R is suitable for neural circuit studies that integrate structural connectivity, cell-type identity, and neurophysiology.

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Linking structure and function in striatum using algebraic topology, digital microcircuit reconstruction and simulations of the healthy and diseased network

10.14293/s2199-1006.1.sor-.ppaemim.v1 ◽

2021 ◽

Author(s):

Ilaria Carannante ◽

Martina Scolamiero ◽

Alexander Kozlov ◽

Lihao Guo ◽

Johannes Hjorth ◽

...

Keyword(s):

Algebraic Topology ◽

Network Dynamics ◽

Structural Connectivity ◽

Projection Neurons ◽

Digital Reconstruction ◽

Striatal Projection Neurons ◽

Structural And Functional Properties ◽

Health And Disease ◽

Using Data ◽

And Function

The relationship between the structure and network dynamics within the striatum is currently not well understood. We have applied algebraic topology to investigate the local structural connectivity in the striatum, and then used simulations to predict how structure shapes network dynamics. We used a full-scale digital reconstruction of the mouse striatal microcircuitry: both healthy and at different stages of Parkinson’s Disease (PD). These stages are characterized by successively modified healthy morphologies of the striatal projection neurons (SPN), including changes in dendritic spine count. We compared the distribution of topological motifs, in the form of directed cliques, between these microcircuits. The distribution of directed cliques in the healthy striatal microcircuits showed that striatal interneurons, despite only accounting for 5%, are crucial for the construction of high dimensional directed cliques. In PD networks the presence of directed cliques drastically decreased with the disease progression. We then used simulations to investigate whether these changes in structural connectivity affect functional connectivity. Signal transfer, especially correlation transfer, in the corticostriatal system was affected. We also found that the resulting changes in intrastriatal inhibition altered the correlations between the striatal projection neurons. Directed cliques already provided insight on structural and functional properties of neocortical micrucircuitry. Here we applied this topological approach to investigate striatal networks and highligthed important differences with respect to neocortex. Combining theory with simulations using data-driven in silico reconstructions will allow us to form quantitative predictions on how structure and network dynamics relate in health and disease.

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Structural neural connectivity analysis in zebrafish with restricted anterograde transneuronal viral labeling and quantitative brain mapping

10.1101/764035 ◽

2019 ◽

Author(s):

Manxiu Ma ◽

Stanislav Kler ◽

Y. Albert Pan

Keyword(s):

Neural Circuit ◽

Structural Connectivity ◽

Helper Virus ◽

Connectivity Analysis ◽

Behavioral Deficits ◽

Topographical Distribution ◽

Brain Structure And Function ◽

Efferent Projections ◽

Labeling Approach ◽

And Function

AbstractThe unique combination of small size, translucency, and powerful genetic tools makes larval zebrafish a uniquely useful vertebrate system to investigate normal and pathological brain structure and function. While functional connectivity can now be assessed (via fluorescent calcium or voltage reporters) at the whole-brain scale, it remains challenging to systematically determine structural connections and identify connectivity changes during development or disease. To address this, we developed Tracer with Restricted Anterograde Spread (TRAS), a novel vesicular stomatitis virus (VSV)-based neural circuit labeling approach. TRAS makes use of replication-incompetent VSV (VSVΔG) and a helper virus (lentivirus) to enable anterograde transneuronal spread between efferent axons and their direct postsynaptic targets but restricts further spread to downstream areas. We integrated TRAS with the Z-Brain zebrafish 3D atlas for quantitative connectivity analysis and identified targets of the retinal and habenular efferent projections, in patterns consistent with previous reports. We compared retinofugal connectivity patterns between wild-type and down syndrome cell adhesion molecule-like 1 (dscaml1) mutant zebrafish and revealed differences in topographical distribution and potential changes in the retinofugal targeting of excitatory versus inhibitory retinorecipient cells. These results demonstrate the utility of TRAS for quantitative structural connectivity analysis that would be valuable for detecting novel efferent targets and mapping connectivity changes underlying neurological or behavioral deficits.

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The NALCN Channel Regulator UNC-80 Functions in a Subset of Interneurons To Regulate Caenorhabditis elegans Reversal Behavior

G3 Genes|Genome|Genetics ◽

10.1534/g3.119.400692 ◽

2019 ◽

Vol 10 (1) ◽

pp. 199-210 ◽

Cited By ~ 1

Author(s):

Chuanman Zhou ◽

Jintao Luo ◽

Xiaohui He ◽

Qian Zhou ◽

Yunxia He ◽

...

Keyword(s):

Plant Hormone ◽

Neuronal Excitability ◽

Resting Membrane Potential ◽

Loss Of Function ◽

Wild Type ◽

C Elegans ◽

Link Type ◽

Complex Functions ◽

And Function ◽

Multiple Loss

NALCN (Na+leak channel, non-selective) is a conserved, voltage-insensitive cation channel that regulates resting membrane potential and neuronal excitability. UNC79 and UNC80 are key regulators of the channel function. However, the behavioral effects of the channel complex are not entirely clear and the neurons in which the channel functions remain to be identified. In a forward genetic screen for C. elegans mutants with defective avoidance response to the plant hormone methyl salicylate (MeSa), we isolated multiple loss-of-function mutations in unc-80 and unc-79. C. elegans NALCN mutants exhibited similarly defective MeSa avoidance. Interestingly, NALCN, unc-80 and unc-79 mutants all showed wild type-like responses to other attractive or repelling odorants, suggesting that NALCN does not broadly affect odor detection or related forward and reversal behaviors. To understand in which neurons the channel functions, we determined the identities of a subset of unc-80-expressing neurons. We found that unc-79 and unc-80 are expressed and function in overlapping neurons, which verified previous assumptions. Neuron-specific transgene rescue and knockdown experiments suggest that the command interneurons AVA and AVE and the anterior guidepost neuron AVG can play a sufficient role in mediating unc-80 regulation of the MeSa avoidance. Though primarily based on genetic analyses, our results further imply that MeSa might activate NALCN by direct or indirect actions. Altogether, we provide an initial look into the key neurons in which the NALCN channel complex functions and identify a novel function of the channel in regulating C. elegans reversal behavior through command interneurons.

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Brain Long Noncoding RNAs: Multitask Regulators of Neuronal Differentiation and Function

Molecules ◽

10.3390/molecules26133951 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3951

Author(s):

Sarva Keihani ◽

Verena Kluever ◽

Eugenio F. Fornasiero

Keyword(s):

Neuronal Differentiation ◽

Neuronal Excitability ◽

Noncoding Rnas ◽

Long Noncoding Rnas ◽

Regulatory Mechanisms ◽

Control Robustness ◽

Living Organisms ◽

And Function ◽

Regulatory Functions ◽

Neuronal Physiology

The extraordinary cellular diversity and the complex connections established within different cells types render the nervous system of vertebrates one of the most sophisticated tissues found in living organisms. Such complexity is ensured by numerous regulatory mechanisms that provide tight spatiotemporal control, robustness and reliability. While the unusual abundance of long noncoding RNAs (lncRNAs) in nervous tissues was traditionally puzzling, it is becoming clear that these molecules have genuine regulatory functions in the brain and they are essential for neuronal physiology. The canonical view of RNA as predominantly a ‘coding molecule’ has been largely surpassed, together with the conception that lncRNAs only represent ‘waste material’ produced by cells as a side effect of pervasive transcription. Here we review a growing body of evidence showing that lncRNAs play key roles in several regulatory mechanisms of neurons and other brain cells. In particular, neuronal lncRNAs are crucial for orchestrating neurogenesis, for tuning neuronal differentiation and for the exact calibration of neuronal excitability. Moreover, their diversity and the association to neurodegenerative diseases render them particularly interesting as putative biomarkers for brain disease. Overall, we foresee that in the future a more systematic scrutiny of lncRNA functions will be instrumental for an exhaustive understanding of neuronal pathophysiology.

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Simple experimental system for mapping inputs to neocortical layer 5 subcerebral projection neurons

Neuroscience Research ◽

10.1016/j.neures.2010.07.1611 ◽

2010 ◽

Vol 68 ◽

pp. e364

Author(s):

Shun Tsuruno ◽

Hisato Maruoka ◽

Rumi Kurokawa ◽

Toshihiko Hosoya

Keyword(s):

Experimental System ◽

Projection Neurons

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Quantifying the Ontogeny of Optokinetic and Vestibuloocular Behaviors in Zebrafish, Medaka, and Goldfish

Journal of Neurophysiology ◽

10.1152/jn.00311.2004 ◽

2004 ◽

Vol 92 (6) ◽

pp. 3546-3561 ◽

Cited By ~ 95

Author(s):

James C. Beck ◽

Edwin Gilland ◽

David W. Tank ◽

Robert Baker

Keyword(s):

Visual Stimulation ◽

Larval Fish ◽

Low Frequency ◽

Velocity Storage ◽

Active Movement ◽

Stimulus Velocity ◽

Oculomotor Behavior ◽

Bode Plots ◽

And Function ◽

Eye Velocity

We quantitatively studied the ontogeny of oculomotor behavior in larval fish as a foundation for studies linking oculomotor structure and function with genetics. Horizontal optokinetic and vestibuloocular reflexes (OKR and VOR, respectively) were measured in three different species (goldfish, zebrafish, and medaka) during the first month after hatching. For all sizes of medaka, and most zebrafish, Bode plots of OKR (0.065–3.0 Hz, ±10°/s) revealed that eye velocity closely followed stimulus velocity (gain > 0.8) at low frequency but dropped sharply above 1 Hz (gain < 0.3 at 3 Hz). Goldfish showed increased gain proportional to size across frequencies. Linearity testing with steps and sinusoids showed excellent visual performance (gain > 0.8) in medaka almost from hatching; but zebrafish and goldfish exhibited progressive improvement, with only the largest equaling medaka performance. Monocular visual stimulation in zebrafish and goldfish produced gains of 0.5 versus <0.1 for the eye viewing a moving versus stationary stimulus pattern but 0.25 versus <0.1 in medaka. Angular VOR appeared much later than OKR, initially at only high accelerations (>200°/s at 0.5 Hz), first in medaka followed by larger (8.11 mm) zebrafish; but it was virtually nonexistent in goldfish. Velocity storage was not observed except for an eye velocity build-up in the largest medaka. In summary, a robust OKR was achieved shortly after hatching in all three species. In contrast, larval fish seem to be unique among vertebrates tested in their lack of significant angular VOR at stages where active movement is required for feeding and survival.

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Cognitive Network Neuroscience

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00810 ◽

2015 ◽

Vol 27 (8) ◽

pp. 1471-1491 ◽

Cited By ~ 194

Author(s):

John D. Medaglia ◽

Mary-Ellen Lynall ◽

Danielle S. Bassett

Keyword(s):

Cognitive Neuroscience ◽

Network Science ◽

Structural Connectivity ◽

Cognitive Network ◽

Network Characteristics ◽

Time Dynamics ◽

Neuroimaging Data ◽

Control Learning ◽

And Function ◽

Network Neuroscience

Network science provides theoretical, computational, and empirical tools that can be used to understand the structure and function of the human brain in novel ways using simple concepts and mathematical representations. Network neuroscience is a rapidly growing field that is providing considerable insight into human structural connectivity, functional connectivity while at rest, changes in functional networks over time (dynamics), and how these properties differ in clinical populations. In addition, a number of studies have begun to quantify network characteristics in a variety of cognitive processes and provide a context for understanding cognition from a network perspective. In this review, we outline the contributions of network science to cognitive neuroscience. We describe the methodology of network science as applied to the particular case of neuroimaging data and review its uses in investigating a range of cognitive functions including sensory processing, language, emotion, attention, cognitive control, learning, and memory. In conclusion, we discuss current frontiers and the specific challenges that must be overcome to integrate these complementary disciplines of network science and cognitive neuroscience. Increased communication between cognitive neuroscientists and network scientists could lead to significant discoveries under an emerging scientific intersection known as cognitive network neuroscience.

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Zebrafish Dscaml1 is Essential for Retinal Patterning and Function of Oculomotor Subcircuits

10.1101/658161 ◽

2019 ◽

Cited By ~ 2

Author(s):

Manxiu Ma ◽

Alexandro D. Ramirez ◽

Tong Wang ◽

Rachel L. Roberts ◽

Katherine E. Harmon ◽

...

Keyword(s):

Animal Model ◽

Light Adaptation ◽

Neural Circuit ◽

Oculomotor System ◽

Gaze Stabilization ◽

Ocular Disorders ◽

Motor Apraxia ◽

Premotor Pathways ◽

And Function ◽

Circuit Function

AbstractDown Syndrome Cell Adhesion Molecules (dscam and dscaml1) are essential regulators of neural circuit assembly, but their roles in vertebrate neural circuit function are still mostly unexplored. We investigated the role of dscaml1 in the zebrafish oculomotor system, where behavior, circuit function, and neuronal activity can be precisely quantified. Loss of zebrafish dscaml1 resulted in deficits in retinal patterning and light adaptation, consistent with its known roles in mammals. Oculomotor analyses showed that mutants have abnormal gaze stabilization, impaired fixation, disconjugation, and faster fatigue. Notably, the saccade and fatigue phenotypes in dscaml1 mutants are reminiscent of human ocular motor apraxia, for which no animal model exists. Two-photon calcium imaging showed that loss of dscaml1 leads to impairment in the saccadic premotor pathway but not the pretectum-vestibular premotor pathway, indicating a subcircuit requirement for dscaml1. Together, we show that dscaml1 has both broad and specific roles in oculomotor circuit function, providing a new animal model to investigate the development of premotor pathways and their associated human ocular disorders.

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Neural contributors to trauma resilience: a review of longitudinal neuroimaging studies

Translational Psychiatry ◽

10.1038/s41398-021-01633-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Alyssa R. Roeckner ◽

Katelyn I. Oliver ◽

Lauren A. M. Lebois ◽

Sanne J. H. van Rooij ◽

Jennifer S. Stevens

Keyword(s):

Individual Differences ◽

Neural Circuit ◽

Major Life ◽

Stress Resilience ◽

Control Networks ◽

The Face ◽

Sensory Cortices ◽

Life Stressor ◽

Threat Cues ◽

And Function

AbstractResilience in the face of major life stressors is changeable over time and with experience. Accordingly, differing sets of neurobiological factors may contribute to an adaptive stress response before, during, and after the stressor. Longitudinal studies are therefore particularly effective in answering questions about the determinants of resilience. Here we provide an overview of the rapidly-growing body of longitudinal neuroimaging research on stress resilience. Despite lingering gaps and limitations, these studies are beginning to reveal individual differences in neural circuit structure and function that appear protective against the emergence of future psychopathology following a major life stressor. Here we outline a neural circuit model of resilience to trauma. Specifically, pre-trauma biomarkers of resilience show that an ability to modulate activity within threat and salience networks predicts fewer stress-related symptoms. In contrast, early post-trauma biomarkers of subsequent resilience or recovery show a more complex pattern, spanning a number of major circuits including attention and cognitive control networks as well as primary sensory cortices. This novel synthesis suggests stress resilience may be scaffolded by stable individual differences in the processing of threat cues, and further buttressed by post-trauma adaptations to the stressor that encompass multiple mechanisms and circuits. More attention and resources supporting this work will inform the targets and timing of mechanistic resilience-boosting interventions.

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Extracellular vesicles (exosomes and ectosomes) play key roles in the pathology of brain diseases

Molecular Biomedicine ◽

10.1186/s43556-021-00040-5 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Jacopo Meldolesi

Keyword(s):

Multiple Sclerosis ◽

Extracellular Vesicles ◽

Brain Diseases ◽

Target Cells ◽

Surface Binding ◽

Cells Of Origin ◽

Relapsing Remitting ◽

And Function ◽

The Brain

AbstractLast century, neurons and glial cells were mostly believed to play distinct functions, relevant for the brain. Progressively, however, it became clear that neurons, astrocytes and microglia co-operate intensely with each other by release/binding of signaling factors, direct surface binding and generation/release of extracellular vesicles, the exosomes and ectosomes, called together vesicles in this abstract. The present review is focused on these vesicles, fundamental in various brain diseases. Their properties are extraordinary. The specificity of their membrane governs their fusion with distinct target cells, variable depending on the state and specificity of their cells of origin and target. Result of vesicle fusion is the discharge of their cargos into the cytoplasm of target cells. Cargos are composed of critical molecules, from proteins (various nature and function) to nucleotides (especially miRNAs), playing critical roles in immune and neurodegenerative diseases. Among immune diseases is multiple sclerosis, affected by extensive dysregulation of co-trafficking neural and glial vesicles, with distinct miRNAs inducing severe or reducing effects. The vesicle-dependent differences between progressive and relapsing-remitting forms of the disease are relevant for clinical developments. In Alzheimer’s disease the vesicles can affect the brain by changing their generation and inducing co-release of effective proteins, such Aβ and tau, from neurons and astrocytes. Specific miRNAs can delay the long-term development of the disease. Upon their traffic through the blood-brainbarrier, vesicles of various origin reach fluids where they are essential for the identification of biomarkers, important for diagnostic and therapeutic innovations, critical for the future of many brain patients.

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