Read by QxMD icon Read


William J Shain, Nicholas A Vickers, Bennett B Goldberg, Thomas Bifano, Jerome Mertz
We present a wide-field fluorescence microscopy add-on that provides a fast, light-efficient extended depth-of-field (EDOF) using a deformable mirror with an update rate of 20 kHz. Out-of-focus contributions in the raw EDOF images are suppressed with a deconvolution algorithm derived directly from the microscope 3D optical transfer function. Demonstrations of the benefits of EDOF microscopy are shown with GCaMP-labeled mouse brain tissue.
March 1, 2017: Optics Letters
Karl J Iremonger, Robert Porteous, Allan E Herbison
Fast cell-to-cell communication in the brain is achieved by action potential-dependent synaptic release of neurotransmitters. The fast kinetics of transmitter release are determined by transient Ca(2+) elevations in presynaptic nerve terminals. Neuromodulators have previously been shown to regulate transmitter release by inhibiting presynaptic Ca(2+) influx. Few studies to date have demonstrated the opposite, that is, neuromodulators directly driving presynaptic Ca(2+) rises and increases in nerve terminal excitability...
February 24, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Jung-Hwa Cho, Carter J Swanson, Jeannie Chen, Ang Li, Lisa G Lippert, Shannon E Boye, Kasey Rose, Sivaraj Sivaramakrishnan, Cheng-Ming Chuong, Robert H Chow
We report on GCaMP-Rs, a new family of genetically encoded ratiometric calcium indicators that extend the virtues of the GCaMP proteins to ratiometric measurements. We have engineered a tandem construct of calcium-dependent GCaMP and calcium-independent mCherry fluorescent proteins. The tandem design assures that the two proteins localize in the same cellular compartment(s) and facilitates pixelwise ratiometric measurements; however, Förster resonance energy transfer (FRET) between the fluorophores reduces brightness of the sensor by up to half (depending on the GCaMP variant)...
March 1, 2017: ACS Chemical Biology
Dongsheng Xiao, Matthieu P Vanni, Catalin C Mitelut, Allen W Chan, Jeffrey M LeDue, Yicheng Xie, Andrew Cn Chen, Nicholas V Swindale, Timothy H Murphy
Understanding the basis of brain function requires knowledge of cortical operations over wide-spatial scales, but also within the context of single neurons. In vivo, wide-field GCaMP imaging and sub-cortical/cortical cellular electrophysiology were used in mice to investigate relationships between spontaneous single neuron spiking and mesoscopic cortical activity. We make use of a rich set of cortical activity motifs that are present in spontaneous activity in anesthetized and awake animals. A mesoscale spike-triggered averaging procedure allowed the identification of motifs that are preferentially linked to individual spiking neurons by employing genetically targeted indicators of neuronal activity...
February 4, 2017: ELife
Kasey S Girven, Dennis R Sparta
The study of neuronal ensembles in awake and behaving animals is a critical question in contemporary neuroscience research. Through the examination of calcium fluctuations, which are correlated with neuronal activity, we are able to better understand complex neural circuits. Recently, the development of technologies including two-photon microscopy, miniature microscopes, and fiber photometry has allowed us to examine calcium activity in behaving subjects over time. Visualizing changes in intracellular calcium in vivo has been accomplished utilizing GCaMP, a genetically encoded calcium indicator...
February 15, 2017: ACS Chemical Neuroscience
Ying Ma, Mohammed A Shaik, Mariel G Kozberg, Sharon H Kim, Jacob P Portes, Dmitriy Timerman, Elizabeth M C Hillman
Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear...
December 27, 2016: Proceedings of the National Academy of Sciences of the United States of America
Nordine Helassa, Borbala Podor, Alan Fine, Katalin Török
Calmodulin-based genetically encoded fluorescent calcium indicators (GCaMP-s) are powerful tools of imaging calcium dynamics from cells to freely moving animals. High affinity indicators with slow kinetics however distort the temporal profile of calcium transients. Here we report the development of reduced affinity ultrafast variants of GCaMP6s and GCaMP6f. We hypothesized that GCaMP-s have a common kinetic mechanism with a rate-limiting process in the interaction of the RS20 peptide and calcium-calmodulin...
December 6, 2016: Scientific Reports
Edward C Emery, Ana P Luiz, Shafaq Sikandar, Rán Magnúsdóttir, Xinzhong Dong, John N Wood
Mechanistic insights into pain pathways are essential for a rational approach to treating this vast and increasing clinical problem. Sensory neurons that respond to tissue damage (nociceptors) may evoke pain sensations and are typically classified on the basis of action potential velocity. Electrophysiological studies have suggested that most of the C-fiber nociceptors are polymodal, responding to a variety of insults. In contrast, gene deletion studies in the sensory neurons of transgenic mice have frequently resulted in modality-specific deficits...
November 2016: Science Advances
Lena van Giesen, G Larisa Neagu-Maier, Jae Young Kwon, Simon G Sprecher
Monitoring neuronal responses to defined sensory stimuli is a powerful and widely used approach for understanding sensory coding in the nervous system. However, providing precise, stereotypic and reproducible cues while concomitantly recording neuronal activity remains technically challenging. Here we describe the fabrication and use of a microfluidics system that allows precise temporally restricted stimulation of Drosophila chemosensory neurons with an array of different chemical cues. The system can easily be combined with genetically encoded calcium sensors, and it can measure neuronal activity at single-cell resolution in larval sense organs and in the proboscis or leg of the adult fly...
December 2016: Nature Protocols
Jung Eun Park, Xian Feng Zhang, Sang-Ho Choi, Junko Okahara, Erika Sasaki, Afonso C Silva
Chronic monitoring of neuronal activity in the living brain with optical imaging techniques became feasible owing to the continued development of genetically encoded calcium indicators (GECIs). Here we report for the first time the successful generation of transgenic marmosets (Callithrix jacchus), an important nonhuman primate model in neurophysiological research, which were engineered to express the green fluorescent protein (GFP)-based family of GECIs, GCaMP, under control of either the CMV or the hSyn promoter...
October 11, 2016: Scientific Reports
Akira Muto, Koichi Kawakami
Visualization of neuronal activity during animal behavior is a critical step in understanding how the brain generates behavior. In the model vertebrate zebrafish, imaging of the brain has been done mostly by using immobilized fish. Here, we describe a novel method to image neuronal activity of the larval zebrafish brain during prey capture behavior. We expressed a genetically encoded fluorescent calcium indicator, GCaMP, in the optic tectum of the midbrain using the Gal4-UAS system. Tectal activity was then imaged in unrestrained larvae during prey perception...
2016: Methods in Molecular Biology
Eyal Seidemann, Yuzhi Chen, Yoon Bai, Spencer C Chen, Preeti Mehta, Bridget L Kajs, Wilson S Geisler, Boris V Zemelman
Understanding the neural basis of behaviour requires studying brain activity in behaving subjects using complementary techniques that measure neural responses at multiple spatial scales, and developing computational tools for understanding the mapping between these measurements. Here we report the first results of widefield imaging of genetically encoded calcium indicator (GCaMP6f) signals from V1 of behaving macaques. This technique provides a robust readout of visual population responses at the columnar scale over multiple mm(2) and over several months...
2016: ELife
John C O'Donnell, Joshua G Jackson, Michael B Robinson
UNLABELLED: Recently, mitochondria have been localized to astrocytic processes where they shape Ca(2+) signaling; this relationship has not been examined in models of ischemia/reperfusion. We biolistically transfected astrocytes in rat hippocampal slice cultures to facilitate fluorescent confocal microscopy, and subjected these slices to transient oxygen/glucose deprivation (OGD) that causes delayed excitotoxic death of CA1 pyramidal neurons. This insult caused a delayed loss of mitochondria from astrocytic processes and increased colocalization of mitochondria with the autophagosome marker LC3B...
July 6, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
J E Cooper, D Natarajan, C J McCann, S Choudhury, H Godwin, A J Burns, N Thapar
The prospect of using neural cell replacement for the treatment of severe enteric neuropathies has seen significant progress in the last decade. The ability to harvest and transplant enteric neural crest cells (ENCCs) that functionally integrate within recipient intestine has recently been confirmed by in vivo murine studies. Although similar cells can be harvested from human fetal and postnatal gut, no studies have as yet verified their functional viability upon in vivo transplantation. We sought to determine whether ENCCs harvested from human fetal bowel are capable of engraftment and functional integration within recipient intestine following in vivo transplantation into postnatal murine colon...
January 2017: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Daniela Brunert, Yusuke Tsuno, Markus Rothermel, Michael T Shipley, Matt Wachowiak
UNLABELLED: Serotonergic neurons in the brainstem raphe nuclei densely innervate the olfactory bulb (OB), where they can modulate the initial representation and processing of olfactory information. Serotonergic modulation of sensory responses among defined OB cell types is poorly characterized in vivo Here, we used cell-type-specific expression of optical reporters to visualize how raphe stimulation alters sensory responses in two classes of GABAergic neurons of the mouse OB glomerular layer, periglomerular (PG) and short axon (SA) cells, as well as mitral/tufted (MT) cells carrying OB output to piriform cortex...
June 22, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Mariel G Kozberg, Ying Ma, Mohammed A Shaik, Sharon H Kim, Elizabeth M C Hillman
UNLABELLED: In the adult brain, increases in neural activity lead to increases in local blood flow. However, many prior measurements of functional hemodynamics in the neonatal brain, including functional magnetic resonance imaging (fMRI) in human infants, have noted altered and even inverted hemodynamic responses to stimuli. Here, we demonstrate that localized neural activity in early postnatal mice does not evoke blood flow increases as in the adult brain, and elucidate the neural and metabolic correlates of these altered functional hemodynamics as a function of developmental age...
June 22, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Saima M Sidik, Miryam A Hortua Triana, Aditya S Paul, Majida El Bakkouri, Caroline G Hackett, Fanny Tran, Nicholas J Westwood, Raymond Hui, William J Zuercher, Manoj T Duraisingh, Silvia N J Moreno, Sebastian Lourido
The life cycles of apicomplexan parasites progress in accordance with fluxes in cytosolic Ca(2+) Such fluxes are necessary for events like motility and egress from host cells. We used genetically encoded Ca(2+) indicators (GCaMPs) to develop a cell-based phenotypic screen for compounds that modulate Ca(2+) signaling in the model apicomplexan Toxoplasma gondii In doing so, we took advantage of the phosphodiesterase inhibitor zaprinast, which we show acts in part through cGMP-dependent protein kinase (protein kinase G; PKG) to raise levels of cytosolic Ca(2+) We define the pool of Ca(2+) regulated by PKG to be a neutral store distinct from the endoplasmic reticulum...
April 29, 2016: Journal of Biological Chemistry
Anne K Streit, Yuen Ngan Fan, Laura Masullo, Richard A Baines
Although there are now a number of antiepileptic drugs (AEDs) available, approximately one-third of epilepsy patients respond poorly to drug intervention. The reasons for this are complex, but are probably reflective of the increasing number of identified mutations that predispose individuals to this disease. Thus, there is a clear requirement for the development of novel treatments to address this unmet clinical need. The existence of gene mutations that mimic a seizure-like behaviour in the fruit fly, Drosophila melanogaster, offers the possibility to exploit the powerful genetics of this insect to identify novel cellular targets to facilitate design of more effective AEDs...
2016: PloS One
Caleb A Doll, Kendal Broadie
Neural circuit optimization occurs through sensory activity-dependent mechanisms that refine synaptic connectivity and information processing during early-use developmental critical periods. Fragile X Mental Retardation Protein (FMRP), the gene product lost in Fragile X syndrome (FXS), acts as an activity sensor during critical period development, both as an RNA-binding translation regulator and channel-binding excitability regulator. Here, we employ a Drosophila FXS disease model to assay calcium signaling dynamics with a targeted transgenic GCaMP reporter during critical period development of the mushroom body (MB) learning/memory circuit...
May 2016: Neurobiology of Disease
Ciara A Martin, Katherine M Myers, Audrey Chen, Nathan T Martin, Angel Barajas, Felix E Schweizer, David E Krantz
Multiple populations of aminergic neurons are affected in Parkinson's disease (PD), with serotonergic and noradrenergic loci responsible for some non-motor symptoms. Environmental toxins, such as the dithiocarbamate fungicide ziram, significantly increase the risk of developing PD and the attendant spectrum of both motor and non-motor symptoms. The mechanisms by which ziram and other environmental toxins increase the risk of PD, and the potential effects of these toxins on aminergic neurons, remain unclear...
January 2016: Experimental Neurology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"