scholarly journals μECoG Recordings Through a Thinned Skull

2019 ◽  
Author(s):  
Sarah K. Brodnick ◽  
Jared P. Ness ◽  
Thomas J. Richner ◽  
Sanitta Thongpang ◽  
Joseph Novello ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Neural Signals ◽  
Electrophysiological Recordings ◽  
Neuroscience Research ◽  
Optically Transparent ◽  
Chronic Study ◽  
Multiple Species ◽  
First Time ◽  
Stimulation Of

AbstractThe studies described in this paper for the first time characterize the acute and chronic performance of optically transparent thin-film µECoG grids implanted on a thinned skull as both an electrophysiological complement to existing thinned skull preparation for optical recordings/manipulations, and a less invasive alternative to epidural or subdurally placed µECoG arrays. In a longitudinal chronic study, µECoG grids placed on top of a thinned skull maintain impedances comparable to epidurally placed µECoG grids that are stable for periods of at least one month. Optogenetic activation of cortex is also reliably demonstrated through the optically transparent ECoG grids acutely placed on the thinned skull. Finally, spatially distinct electrophysiological recordings were evident on µECoG electrodes placed on a thinned skull separated by 500-750µm, as assessed by stimulation evoked responses using optogenetic activation of cortex as well as invasive and epidermal stimulation of the sciatic and median nerve at chronic time points. Neural signals were collected through a thinned skull in multiple species, demonstrating potential utility in neuroscience research applications such as in vivo imaging, optogenetics, calcium imaging, and neurovascular coupling.

scholarly journals 0074 Inhibitory Neurons in the Dorsomedial Medulla Promote REM Sleep

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A30-A30
Author(s):  
J Stucynski ◽  
A Schott ◽  
J Baik ◽  
J Hong ◽  
F Weber ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Nrem Sleep ◽  
Inhibitory Neurons ◽  
Brain State ◽  
Sleep Regulation ◽  
Optogenetic Stimulation ◽  
Electrophysiological Recordings ◽  
Stimulation Of

Abstract Introduction The neural circuits controlling rapid eye movement (REM) sleep, and in particular the role of the medulla in regulating this brain state, remains an active area of study. Previous electrophysiological recordings in the dorsomedial medulla (DM) and electrical stimulation experiments suggested an important role of this area in the control of REM sleep. However the identity of the involved neurons and their precise role in REM sleep regulation are still unclear. Methods The properties of DM GAD2 neurons in mice were investigated through stereotaxic injection of CRE-dependent viruses in conjunction with implantation of electrodes for electroencephalogram (EEG) and electromyogram (EMG) recordings and optic fibers. Experiments included in vivo calcium imaging (fiber photometry) across sleep and wake states, optogenetic stimulation of cell bodies, chemogenetic excitation and suppression (DREADDs), and connectivity mapping using viral tracing and optogenetics. Results Imaging the calcium activity of DM GAD2 neurons in vivo indicates that these neurons are most active during REM sleep. Optogenetic stimulation of DM GAD2 neurons reliably triggered transitions into REM sleep from NREM sleep. Consistent with this, chemogenetic activation of DM GAD2 neurons increased the amount of REM sleep while inhibition suppressed its occurrence and enhanced NREM sleep. Anatomical tracing revealed that DM GAD2 neurons project to several areas involved in sleep / wake regulation including the wake-promoting locus coeruleus (LC) and the REM sleep-suppressing ventrolateral periaquaductal gray (vlPAG). Optogenetic activation of axonal projections from DM to LC, and DM to vlPAG was sufficient to induce REM sleep. Conclusion These experiments demonstrate that DM inhibitory neurons expressing GAD2 powerfully promote initiation of REM sleep in mice. These findings further characterize the dorsomedial medulla as a critical structure involved in REM sleep regulation and inform future investigations of the REM sleep circuitry. Support R01 HL149133

scholarly journals beta-Naphthoflavone abolishes interrenal sensitivity to ACTH stimulation in rainbow trout

1998 ◽  
Vol 157 (1) ◽  
pp. 63-70 ◽  
Author(s):  
JM Wilson ◽  
MM Vijayan ◽  
CJ Kennedy ◽  
GK Iwama ◽  
TW Moon
Keyword(s):  
Cytochrome P450 ◽  
Rainbow Trout ◽  
Acth Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Treated Fish ◽  
First Time ◽  
Hepatic Cytochrome ◽  
Stimulation Of

We report for the first time that beta-naphthoflavone (BNF) abolishes ACTH stimulation of cortisol production in rainbow trout (Oncorhynchus mykiss). There was significantly higher hepatic cytochrome P450 content and ethoxyresorufin O-de-ethylase and uridine-5'-diphosphoglucuronic acid transferase activities in BNF-treated fish than in sham-treated controls. BNF did not significantly affect either plasma turnover or tissue distribution of [3H]cortisol-derived radioactivity. Hepatic membrane fluidity and hepatocyte capacity for cortisol uptake were not altered by BNF as compared with the sham-treated fish. These results taken together suggest that BNF does not affect cortisol-clearance mechanisms in trout. A 3 min handling disturbance period elicited a plasma cortisol response in the sham-treated fish; however, the response in the BNF-treated fish was muted and significantly lower than in the sham fish. This in vivo response corroborates the lack of interrenal sensitivity to ACTH in vitro in the BNF-treated fish, suggesting that BNF affects the ACTH pathway in trout. Our results suggest the possibility that cytochrome P450-inducing compounds may affect cortisol dynamics by decreasing interrenal responsiveness to ACTH stimulation in fish, thereby impairing the physiological responses that are necessary for the animal to cope with the stressor.

scholarly journals Rapid Magneto-Sonoporation of Adipose-Derived Cells

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4877
Author(s):  
Miriam Filippi ◽  
Boris Dasen ◽  
Arnaud Scherberich
Keyword(s):  
Stem Cells ◽  
Tissue Repair ◽  
Morphological Changes ◽  
Adipose Derived Stem Cells ◽  
Resonance Imaging ◽  
Membrane Resealing ◽  
First Time ◽  
Stimulation Of

By permeabilizing the cell membrane with ultrasound and facilitating the uptake of iron oxide nanoparticles, the magneto-sonoporation (MSP) technique can be used to instantaneously label transplantable cells (like stem cells) to be visualized via magnetic resonance imaging in vivo. However, the effects of MSP on cells are still largely unexplored. Here, we applied MSP to the widely applicable adipose-derived stem cells (ASCs) for the first time and investigated its effects on the biology of those cells. Upon optimization, MSP allowed us to achieve a consistent nanoparticle uptake (in the range of 10 pg/cell) and a complete membrane resealing in few minutes. Surprisingly, this treatment altered the metabolic activity of cells and induced their differentiation towards an osteoblastic profile, as demonstrated by an increased expression of osteogenic genes and morphological changes. Histological evidence of osteogenic tissue development was collected also in 3D hydrogel constructs. These results point to a novel role of MSP in remote biophysical stimulation of cells with focus application in bone tissue repair.

Fabrication and Characterization of Biodegradable Metal Based Microelectrodes for In Vivo Neural Recording

MRS Advances ◽  
2019 ◽  
Vol 4 (46-47) ◽  
pp. 2471-2477
Author(s):  
Chaoxing Zhang ◽  
Teresa H. Wen ◽  
Khaleel A. Razak ◽  
Jiajia Lin ◽  
Edgar Villafana ◽  
...  
Keyword(s):  
Neural Recording ◽  
Neural Signals ◽  
Secondary Surgery ◽  
New Class ◽  
Fabrication And Characterization ◽  
Evoked Activity ◽  
First Time ◽  
The Brain

ABSTRACT:Neural electrodes have been widely used to monitor neural signals and/or deliver electrical stimulation in the brain. Currently, biodegradable and biocompatible materials have been actively investigated to create temporary electrodes that could degrade after serving their functions for neural recording and stimulation from days to months. The new class of biodegradable electrodes eliminate the necessity of secondary surgery for electrode removal. In this study, we created biodegradable, biocompatible, and implantable magnesium (Mg)-based microelectrodes for in vivo neural recording for the first time. Specifically, conductive poly-3,4-ethylenedioxythiophene (PEDOT) was first deposited onto Mg microwire substrates by electrochemical deposition, and a biodegradable insulating polymer was subsequently sprayed onto the surface of electrodes. The tip of electrodes was designed to be conductive for neural recording and stimulation, while the rest of electrodes was insulated with a polymer that is biocompatible with neural tissue. The impedance of Mg-based microelectrodes and their performance during neural recording in the auditory cortex of a mouse were studied. The results first demonstrated the capability of Mg-based microelectrodes for in vivo recording of multi-unit stimulus-evoked activity in the brain.

scholarly journals The horse as a model for translational orthopedic research: examples of studies on the regeneration of cartilage and bone conducted in Costa Rica

2019 ◽  
Vol 37 (3) ◽  
pp. 9-10
Author(s):  
Rafael Vindas Bolaños ◽  
Jos Malda ◽  
René Van Weeren ◽  
Janny De Grauw
Keyword(s):  
Bone Defects ◽  
Chondral Defects ◽  
Fixation Techniques ◽  
Equine Studies ◽  
First Time ◽  
Adhesive Capacity ◽  
Stimulation Of ◽  
Long Term Studies

The paper provides results published or to be published of long-term in vivo equine studies to evaluate techniques of possible regenerative matrices of cartilage and bone, by means of cell-free implants or stimulation of the bone marrow. From the fixation techniques analyzed, it can be concluded that the best alternatives are the pressure technique for subchondral defects and a novel hydrogel with self-adhesive capacity for chondral defects. The equine coxal tuberosity was used for the first time as a model for regeneration studies of bone defects, analyzing scaffolds based on tricalcium phosphate, polymers and nanoparticles, by means of 3-D printing. Osteoconductivity, osteoinductivity, and the importance of microporosity were documented.Given that decellularized materials do not always give significant desired results in the regeneration of cartilage, it is important to conduct long-term studies. The technique of nanofracture and a novel self-adhesive hydrogel in the knee of the equine showed promising preliminary results in the regeneration of cartilage.The knee and the coxal tuberosity of the horse represent models of studying cartilage and bone regeneration in a true translational sense as a source of highly valuable information for clinical studies, for both horses and humans.

scholarly journals Precocious development of uridine diphosphate glucuronosyltransferase activity during organ culture of foetal rat liver in the presence of glucocorticoids

1977 ◽  
Vol 166 (2) ◽  
pp. 249-253 ◽  
Author(s):  
G J Wishart ◽  
M A Goheer ◽  
J E A Leakey ◽  
G J Dutton
Keyword(s):  
Rat Liver ◽  
Defined Medium ◽  
Transferase Activity ◽  
Uridine Diphosphate ◽  
Chemically Defined Medium ◽  
Foetal Rat ◽  
First Time ◽  
Precocious Development ◽  
Stimulation Of

1. Precocious development of mammalian UDP-glucuronosyltransferase (EC 2.4.1.1.7) induced by endogenous compounds of known chemical composition is reported for the first time. 2. This development occurs in cultured explants of foetal rat liver when exposed to corticosteroids possessing a pregn-4′-ene structure and a hydroxy or an oxo group at C-11. 3. Explants from 14-day foetuses cultured for 3 days in a chemically defined medium containing dexamethasone exhibited transferase activities towards o-aminophenol within adult male values. Those liver transferase activities attained in utero by 17 days were still negligible. 4. Evidence from several approaches indicated that the explants required glucocorticoids for expression of the transferase, not for maintenance of viability. 5. Glucocorticoid-dependent stimulation of transferase activity required incorporation of L-[14C]leucine into protein, as judged from the pulsing of cultures with cycloheximide. 6. The relevance of these culture experiments to the situation in vivo is discussed.

scholarly journals Intracellular pH of astrocytes increases rapidly with cortical stimulation

1987 ◽  
Vol 253 (4) ◽  
pp. R666-R670 ◽  
Author(s):  
M. Chesler ◽  
R. P. Kraig
Keyword(s):  
Electrical Activity ◽  
Intracellular Ph ◽  
Brain Function ◽  
Spreading Depression ◽  
Alkaline Shift ◽  
Functional Implications ◽  
First Time ◽  
The Brain ◽  
Stimulation Of

Modulation of intracellular pH is widely implicated in the control of cell growth and metabolism, yet little is known about intracellular pH and brain function. To determine how stimulation of brain may affect the intracellular pH of mammalian glial cells, rat cortical astrocytes were studied for the first time in vivo using pH-sensitive electrodes of submicron caliber. Stimulation of the cortical surface caused a cytoplasmic alkaline shift of tenths of a pH within seconds. Cessation of induced electrical activity was followed by pH recovery and a small acid rebound. Recordings obtained during cortical-spreading depression revealed similar but generally larger intracellular pH shifts. Production of metabolic acids is known to occur when the brain is stimulated and has led to the long-held presumption that brain cells accordingly become more acidic. The observation that glia initially become more alkaline during electrical activity is thus paradoxical. The correlation of glial alkalinization with evoked electrical activity suggests that modulation of intracellular pH of glia may have important functional implications.

scholarly journals IGF-I Signaling Is Essential for FSH Stimulation of AKT and Steroidogenic Genes in Granulosa Cells

2013 ◽  
Vol 27 (3) ◽  
pp. 511-523 ◽  
Author(s):  
Ping Zhou ◽  
Sarah C. Baumgarten ◽  
Yanguang Wu ◽  
Jill Bennett ◽  
Nicola Winston ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Akt Phosphorylation ◽  
Akt Activation ◽  
In Vivo Experiments ◽  
Igf I ◽  
First Time ◽  
Cyp19 Expression ◽  
Stimulation Of ◽  
Steroidogenic Genes

Abstract FSH and IGF-I synergistically stimulate gonadal steroid production; conversely, silencing the FSH or the IGF-I genes leads to infertility and hypogonadism. To determine the molecular link between these hormones, we examined the signaling cross talk downstream of their receptors. In human and rodent granulosa cells (GCs), IGF-I potentiated the stimulatory effects of FSH and cAMP on the expression of steroidogenic genes. In contrast, inhibition of IGF-I receptor (IGF-IR) activity or expression using pharmacological, genetic, or biochemical approaches prevented the FSH- and cAMP-induced expression of steroidogenic genes and estradiol production. In vivo experiments demonstrated that IGF-IR inactivation reduces the stimulation of steroidogenic genes and follicle growth by gonadotropins. FSH or IGF-I alone stimulated protein kinase B (PKB), which is also known as AKT and in combination synergistically increased AKT phosphorylation. Remarkably, blocking IGF-IR expression or activity decreased AKT basal activity and abolished AKT activation by FSH. In GCs lacking IGF-IR activity, FSH stimulation of Cyp19 expression was rescued by overexpression of constitutively active AKT. Our findings demonstrate, for the first time, that in human, mouse, and rat GCs, the well-known stimulatory effect of FSH on Cyp19 and AKT depends on IGF-I and on the expression and activation of the IGF-IR.

scholarly journals MIN1PIPE: A Miniscope 1-photon-based Calcium Imaging Signal Extraction Pipeline

2018 ◽  
Author(s):  
Jinghao Lu ◽  
Chunyuan Li ◽  
Jonnathan Singh-Alvarado ◽  
Zhe Charles Zhou ◽  
Flavio Fröhlich ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Parameter Tuning ◽  
Superior Performance ◽  
Imaging Method ◽  
Imaging Data ◽  
Neural Signals ◽  
Neural Activities ◽  
Wide Range ◽  
Photon Imaging

SUMMARYIn vivo calcium imaging using 1-photon based miniscope and microendoscopic lens enables studies of neural activities in freely behaving animals. However, the high and fluctuating background, the inevitable movements and distortions of imaging field, and the extensive spatial overlaps of fluorescent signals emitted from imaged neurons inherent in this 1-photon imaging method present major challenges for extracting neuronal signals reliably and automatically from the raw imaging data. Here we develop a unifying algorithm called MINiscope 1-photon imaging PIPEline (MIN1PIPE) that contains several standalone modules and can handle a wide range of imaging conditions and qualities with minimal parameter tuning, and automatically and accurately isolate spatially localized neural signals. We quantitatively compare MIN1PIPE with other existing partial methods using both synthetic and real datasets obtained from different animal models, and show that MIN1PIPE has a superior performance both in terms of efficiency and precision in analyzing noisy miniscope calcium imaging data.

The 9E3 protein: immunolocalization in vivo and evidence for multiple forms in culture

1992 ◽  
Vol 101 (3) ◽  
pp. 701-707
Author(s):  
M. Martins-Green ◽  
A. Aotaki-Keen ◽  
L.M. Hjelmeland ◽  
M.J. Bissell
Keyword(s):  
Synthetic Peptide ◽  
Scar Tissue ◽  
High Homology ◽  
Multiple Forms ◽  
Quiescent Cells ◽  
Serum Stimulation ◽  
Induced Tumors ◽  
First Time ◽  
Stimulation Of

The avian gene 9E3/CEF4 belongs to a group of genes whose products are highly conserved and are homologous to inflammatory mediators. These genes, sometimes referred to as the gro family, are also expressed upon wounding or serum-stimulation of quiescent cells, suggesting that they may be important in aspects of growth and/or wound healing. We have used an antibody to the product of the 9E3 gene to show for the first time the distribution in vivo of the protein of one of these genes. The polyclonal antibody was produced against a synthetic peptide, [Cys76], 9E3, (77–103), located at the carboxy end of the molecule. The specificity of the antibody was determined by transfection of the 9E3 cDNA into Cos 7 cells, which do not express this gene. Moreover, despite the high homology between 9E3 and IL-8, the antibody did not crossreact with this molecule. The antibody was used to immuno-precipitate the protein from cultured normal and RSV-transformed chick embryo fibroblasts (CEFs) and to determine its distribution in tissues of newly hatched chicks. The staining was abundant in the cells and extracellular matrix (ECM) of connective tissue and other tissues of mesenchymal origin, such as bone and tendon. Most cells in the granulation tissue of wounds stained, some more intensely than others; the ECM also stained, especially in areas of scar tissue where collagen is abundant. In RSV-induced tumors, the protein was absent except in necrotic areas where a few cells—potentially macrophages—stained. In general, as expected, the protein was present in the cells and tissues that expressed the mRNA, but there were exceptions.(ABSTRACT TRUNCATED AT 250 WORDS)

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