scholarly journals Rapid purification and metabolomic profiling of synaptic vesicles from mammalian brain

2020 ◽  
Author(s):  
Lynne Chantranupong ◽  
Jessica L. Saulnier ◽  
Wengang Wang ◽  
Drew R. Jones ◽  
Michael E. Pacold ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Synaptic Vesicles ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Metabolomic Profiling ◽  
Polar Metabolites ◽  
A Cell ◽  
Cell Type Specific ◽  
Rapid Purification ◽  
Activity Dependent

AbstractNeurons communicate by the activity-dependent release of small-molecule neurotransmitters packaged into synaptic vesicles (SVs). Although many molecules have been identified as neurotransmitters, technical limitations have precluded a full metabolomic analysis of synaptic vesicle content. Here, we present a workflow to rapidly isolate SVs and to interrogate their metabolic contents at a high-resolution using mass spectrometry. We validated the enrichment of glutamate in SVs of primary cortical neurons using targeted polar metabolomics. Unbiased and extensive global profiling of SVs isolated from these neurons revealed that the only detectable polar metabolites they contain are the established neurotransmitters glutamate and GABA. Finally, we adapted the approach to enable quick capture of SVs directly from brain tissue and determined the neurotransmitter profiles of diverse brain regions in a cell-type specific manner. The speed, robustness, and precision of this method to interrogate SV contents will facilitate novel insights into the chemical basis of neurotransmission.

scholarly journals Rapid purification and metabolomic profiling of synaptic vesicles from mammalian brain

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Lynne Chantranupong ◽  
Jessica L Saulnier ◽  
Wengang Wang ◽  
Drew R Jones ◽  
Michael E Pacold ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Synaptic Vesicles ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Metabolomic Profiling ◽  
Polar Metabolites ◽  
A Cell ◽  
Cell Type Specific ◽  
Rapid Purification ◽  
Activity Dependent

Neurons communicate by the activity-dependent release of small-molecule neurotransmitters packaged into synaptic vesicles (SVs). Although many molecules have been identified as neurotransmitters, technical limitations have precluded a full metabolomic analysis of SV content. Here, we present a workflow to rapidly isolate SVs and to interrogate their metabolic contents at high-resolution using mass spectrometry. We validated the enrichment of glutamate in SVs of primary cortical neurons using targeted polar metabolomics. Unbiased and extensive global profiling of SVs isolated from these neurons revealed that the only detectable polar metabolites they contain are the established neurotransmitters glutamate and GABA. In addition, we adapted the approach to enable quick capture of SVs directly from brain tissue and determined the neurotransmitter profiles of diverse brain regions in a cell-type-specific manner. The speed, robustness, and precision of this method to interrogate SV contents will facilitate novel insights into the chemical basis of neurotransmission.

scholarly journals Author response: Rapid purification and metabolomic profiling of synaptic vesicles from mammalian brain

2020 ◽  
Author(s):  
Lynne Chantranupong ◽  
Jessica L Saulnier ◽  
Wengang Wang ◽  
Drew R Jones ◽  
Michael E Pacold ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Author Response ◽  
Mammalian Brain ◽  
Metabolomic Profiling ◽  
Rapid Purification

scholarly journals Taste quality representation in the human brain

2019 ◽  
Author(s):  
Jason A. Avery ◽  
Alexander G. Liu ◽  
John E. Ingeholm ◽  
Cameron D. Riddell ◽  
Stephen J. Gotts ◽  
...  
Keyword(s):  
Human Brain ◽  
Cortical Neurons ◽  
Brain Regions ◽  
Taste Quality ◽  
7 Tesla ◽  
Mammalian Brain ◽  
High Magnetic Field Strength ◽  
Magnetic Resonance Imaging Mri ◽  
Spatial Locations ◽  
Univariate Analyses

SUMMARYIn the mammalian brain, the insula is the primary cortical substrate involved in the perception of taste. Recent imaging studies in rodents have identified a gustotopic organization in the insula, whereby distinct insula regions are selectively responsive to one of the five basic tastes. However, numerous studies in monkeys have reported that gustatory cortical neurons are broadly-tuned to multiple tastes, and tastes are not represented in discrete spatial locations. Neuroimaging studies in humans have thus far been unable to discern between these two models, though this may be due to the relatively low spatial resolution employed in taste studies to date. In the present study, we examined the spatial representation of taste within the human brain using ultra-high resolution functional magnetic resonance imaging (MRI) at high magnetic field strength (7-Tesla). During scanning, participants tasted sweet, salty, sour and tasteless liquids, delivered via a custom-built MRI-compatible tastant-delivery system. Our univariate analyses revealed that all tastes (vs. tasteless) activated primary taste cortex within the bilateral dorsal mid-insula, but no brain region exhibited a consistent preference for any individual taste. However, our multivariate searchlight analyses were able to reliably decode the identity of distinct tastes within those mid-insula regions, as well as brain regions involved in affect and reward, such as the striatum, orbitofrontal cortex, and amygdala. These results suggest that taste quality is not represented topographically, but by a combinatorial spatial code, both within primary taste cortex as well as regions involved in processing the hedonic and aversive properties of taste.

scholarly journals Cell Type-Specific Role of RNA Nuclease SMG6 in Neurogenesis

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3365
Author(s):  
Gabriela Maria Guerra ◽  
Doreen May ◽  
Torsten Kroll ◽  
Philipp Koch ◽  
Marco Groth ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Cortical Neurons ◽  
Embryonic Stem ◽  
Normal Structure ◽  
Mutant Mice ◽  
Cell Type ◽  
Nonsense Mediated Mrna Decay ◽  
A Cell ◽  
Cell Type Specific

SMG6 is an endonuclease, which cleaves mRNAs during nonsense-mediated mRNA decay (NMD), thereby regulating gene expression and controling mRNA quality. SMG6 has been shown as a differentiation license factor of totipotent embryonic stem cells. To investigate whether it controls the differentiation of lineage-specific pluripotent progenitor cells, we inactivated Smg6 in murine embryonic neural stem cells. Nestin-Cre-mediated deletion of Smg6 in mouse neuroprogenitor cells (NPCs) caused perinatal lethality. Mutant mice brains showed normal structure at E14.5 but great reduction of the cortical NPCs and late-born cortical neurons during later stages of neurogenesis (i.e., E18.5). Smg6 inactivation led to dramatic cell death in ganglionic eminence (GE) and a reduction of interneurons at E14.5. Interestingly, neurosphere assays showed self-renewal defects specifically in interneuron progenitors but not in cortical NPCs. RT-qPCR analysis revealed that the interneuron differentiation regulators Dlx1 and Dlx2 were reduced after Smg6 deletion. Intriguingly, when Smg6 was deleted specifically in cortical and hippocampal progenitors, the mutant mice were viable and showed normal size and architecture of the cortex at E18.5. Thus, SMG6 regulates cell fate in a cell type-specific manner and is more important for neuroprogenitors originating from the GE than for progenitors from the cortex.

scholarly journals Inferring cortical function in the mouse visual system through large-scale systems neuroscience

2016 ◽  
Vol 113 (27) ◽  
pp. 7337-7344 ◽  
Author(s):  
Michael Hawrylycz ◽  
Costas Anastassiou ◽  
Anton Arkhipov ◽  
Jim Berg ◽  
Michael Buice ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Large Scale ◽  
Model Organism ◽  
Building Blocks ◽  
Mammalian Brain ◽  
Cortical Function ◽  
Scientific Mission ◽  
Large Populations ◽  
Cell Type Specific ◽  
And Behavior

The scientific mission of the Project MindScope is to understand neocortex, the part of the mammalian brain that gives rise to perception, memory, intelligence, and consciousness. We seek to quantitatively evaluate the hypothesis that neocortex is a relatively homogeneous tissue, with smaller functional modules that perform a common computational function replicated across regions. We here focus on the mouse as a mammalian model organism with genetics, physiology, and behavior that can be readily studied and manipulated in the laboratory. We seek to describe the operation of cortical circuitry at the computational level by comprehensively cataloging and characterizing its cellular building blocks along with their dynamics and their cell type-specific connectivities. The project is also building large-scale experimental platforms (i.e., brain observatories) to record the activity of large populations of cortical neurons in behaving mice subject to visual stimuli. A primary goal is to understand the series of operations from visual input in the retina to behavior by observing and modeling the physical transformations of signals in the corticothalamic system. We here focus on the contribution that computer modeling and theory make to this long-term effort.

scholarly journals GABA—from Inhibition to Cognition: Emerging Concepts

2017 ◽  
Vol 24 (5) ◽  
pp. 501-515 ◽  
Author(s):  
T. Schmidt-Wilcke ◽  
E. Fuchs ◽  
K. Funke ◽  
A. Vlachos ◽  
F. Müller-Dahlhaus ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Resonance Spectroscopy ◽  
Inhibitory Neurotransmitter ◽  
Electrophysiological Properties ◽  
Potential Strategy ◽  
The One ◽  
And Behavior

Neural functioning and plasticity can be studied on different levels of organization and complexity ranging from the molecular and synaptic level to neural circuitry of whole brain networks. Across neuroscience different methods are being applied to better understand the role of various neurotransmitter systems in the evolution of perception and cognition. GABA is the main inhibitory neurotransmitter in the adult mammalian brain and, depending on the brain region, up to 25% of the total number of cortical neurons are GABAergic interneurons. At the one end of the spectrum, GABAergic neurons have been accurately described with regard to cell morphological, molecular, and electrophysiological properties; at the other end researchers try to link GABA concentrations in specific brain regions to human behavior using magnetic resonance spectroscopy. One of the main challenges of modern neuroscience currently is to integrate knowledge from highly specialized subfields at distinct biological scales into a coherent picture that bridges the gap between molecules and behavior. In the current review, recent findings from different fields of GABA research are summarized delineating a potential strategy to develop a more holistic picture of the function and role of GABA.

scholarly journals Cannabinoid type 2 receptors mediate a cell type-specific self-inhibition in cortical neurons

2018 ◽  
Vol 139 ◽  
pp. 217-225 ◽  
Author(s):  
Alexander Stumpf ◽  
Daniel Parthier ◽  
Rosanna P. Sammons ◽  
A. Vanessa Stempel ◽  
Jörg Breustedt ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Cell Type ◽  
A Cell ◽  
Cell Type Specific

scholarly journals A splicing isoform of GPR56 mediates microglial synaptic refinement via phosphatidylserine binding

2020 ◽  
Author(s):  
Tao Li ◽  
Brian Chiou ◽  
Casey K Gilman ◽  
Rong Luo ◽  
Tatsuhiro Koshi ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Brain Regions ◽  
Oligodendrocyte Progenitor Cells ◽  
Synaptic Remodeling ◽  
Domain Specific ◽  
Specific Manner ◽  
Alternatively Spliced ◽  
A Cell ◽  
Cell Type Specific

AbstractDevelopmental synaptic remodeling is important for the formation of precise neural circuitry and its disruption has been linked to neurodevelopmental disorders such as autism and schizophrenia. Microglia prune synapses, but integration of this synapse pruning with overlapping and concurrent neurodevelopmental processes remains elusive. Adhesion G protein-coupled receptor ADGRG1/GPR56 controls multiple aspects of brain development in a cell type-specific manner: in neural progenitor cells, GPR56 regulates cortical lamination, whereas in oligodendrocyte progenitor cells, GPR56 controls developmental myelination and myelin repair. Here, we show that microglial GPR56 maintains appropriate synaptic numbers in several brain regions in a time- and circuit-dependent fashion. Phosphatidylserine (PS) on pre-synaptic elements binds GPR56 in a domain-specific manner, and microglia-specific deletion of Gpr56 leads to increased synapses as a result of reduced microglial engulfment of PS+ pre-synaptic inputs. Remarkably, a particular alternatively spliced isoform of GPR56 is selectively required for microglia-mediated synaptic pruning. Our present data provide a ligand- and isoform-specific mechanism underlying microglial GPR56-mediated synapse pruning in the context of complex neurodevelopmental processes.

scholarly journals Single-cell transcriptomics and cell-specific proteomics reveals molecular signatures of sleep

2020 ◽  
Author(s):  
Pawan K. Jha ◽  
Utham K. Valekunja ◽  
Sandipan Ray ◽  
Mathieu Nollet ◽  
Akhilesh B. Reddy
Keyword(s):  
Single Cell ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Brain Regions ◽  
Specific Protein ◽  
Cell Type ◽  
Transcriptional Responses ◽  
A Cell ◽  
Cell Type Specific ◽  
Different Cell Types

Every day, we sleep for a third of the day. Sleep is important for cognition, brain waste clearance, metabolism, and immune responses. The molecular mechanisms governing sleep are largely unknown. Here, we used a combination of single cell RNA sequencing and cell-type specific proteomics to interrogate the molecular underpinnings of sleep. Different cell types in three important brain regions for sleep (brainstem, cortex, and hypothalamus) exhibited diverse transcriptional responses to sleep need. Sleep restriction modulates astrocyte-neuron crosstalk and sleep need enhances expression of specific sets of transcription factors in different brain regions. In cortex, we also interrogated the proteome of two major cell types: astrocytes and neurons. Sleep deprivation differentially alters the expression of proteins in astrocytes and neurons. Similarly, phosphoproteomics revealed large shifts in cell-type specific protein phosphorylation. Our results indicate that sleep need regulates transcriptional, translational, and post-translational responses in a cell-specific manner.

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