scholarly journals Thalamic encoding of complex sensory patterns and its possible role in cognition

2020 ◽  
Author(s):  
Carlos Castejon ◽  
Jesus Martin-Cortecero ◽  
Angel Nuñez
Keyword(s):  
Cortical Area ◽  
List Type ◽  
Spatiotemporal Structure ◽  
Extracellular Recordings ◽  
Sustained Activity ◽  
Cortical Areas ◽  
Functional Perspective ◽  
Highly Sensitive ◽  
Ipsilateral Stimulation

AbstractThe function of the higher-order sensory thalamus remains unresolved. Here, POm nucleus was examined by in vivo extracellular recordings across a range of complex sensory patterns. We found that POm was highly sensitive to multiwhisker stimuli involving complex spatiotemporal interactions. The dynamical spatiotemporal structure of sensory patterns and the different complexity of their parts were accurately reflected in precise POm activity changes. Importantly, POm was also able to respond to ipsilateral stimulation and was implicated in the representation of bilateral tactile events by integrating simultaneous signals arising from both whisker pads. We found that POm nuclei are mutually connected through the cortex forming a functional POm-POm loop. We unravelled the nature and content of the messages travelling through this loop showing that they were ‘structured patterns of sustained activity’. These structured messages were transmitted preserving their integrated structure. The implication of different cortical areas was investigated revealing that S1 plays a protagonist role in this functional loop. Our results also demonstrated different laminar implication in the processing of sustained activity in this cortical area and its transmission between hemispheres. We propose a theoretical model in which these ‘structured patterns of sustained activity’ generated by POm may play important roles in perceptual, motor and cognitive functions. From a functional perspective, this proposal, supported by the results described here, provides a novel theoretical framework to understand the implication of the thalamus in cognition. In addition, a profound difference was found between VPM and POm functioning. The hypothesis of Complementary Components is proposed here to explain it.HighlightsPOm is implicated in the representation of complex sensory patterns.POm is implicated in the encoding of bilateral tactile events.POm nuclei are mutually connected through the cortex forming a functional POm-POm loop.‘Structured patterns of sustained activity’ travelling through the loopAbstract Figure

LACK OF EFFECT OF CORTICOSTEROIDS ON THE IN VIVO DISAPPEARANCE OF SULFHYDRYL-INHIBITED AND ANTIBODY-COATED ERYTHROCYTES

1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S28-S36
Author(s):  
Kailash N. Agarwal
Keyword(s):  
Red Cells ◽  
List Type ◽  
Red Cell

ABSTRACT Red cells were incubated in vitro with sulfhydryl inhibitors and Rhantibody with and without prior incubation with prednisolone-hemisuccinate. These erythrocytes were labelled with Cr51 and P32 and their disappearance in vivo after autotransfusion was measured. Prior incubation with prednisolone-hemisuccinate had no effect on the rate of red cell disappearance. The disappearance of the cells was shown to take place without appreciable intravascular destruction.

STUDIES IN CONGENITAL GENERALIZED LIPODYSTROPHY

1973 ◽  
Vol 72 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Oddmund Søvik ◽  
Svein Oseid
Keyword(s):  
Biological Activity ◽  
Insulin Response ◽  
Epididymal Adipose Tissue ◽  
Large Individual ◽  
Immunoreactive Insulin ◽  
List Type ◽  
Glucose Load ◽  
Congenital Generalized Lipodystrophy ◽  
The One

ABSTRACT The biological activity of plasma insulin from 4 cases of congenital generalized lipodystrophy has been studied, using rat diaphragm and epididymal adipose tissue in vivo. The results are compared with previous data on plasma immunoreactive insulin obtained in these patients. 2 of the 4 cases exhibited unusually high biological insulin activities during the fasting state as well as after an intravenous (iv) glucose load. In the fat pad assay activities as high as 10 000 μU insulin per ml were observed. During childhood the biological insulin activities were generally high, although there were large individual variations. However, in the one case studied after the age of puberty, the insulin response to a glucose load was negligible. Taken together, the biological and immunological activities observed strongly suggest the presence of pancreatic insulin in these patients. It appears that the circulating insulin has a fully biological activity. The decreasing insulin activities after cessation of growth are in agreement with the appearance of frank diabetes at this time.

Synthesis and 31 P NMR characterization of new low toxic highly sensitive pH probes designed for in vivo acidic pH studies

2002 ◽  
Vol 10 (5) ◽  
pp. 1451-1458 ◽  
Author(s):  
Sophie Martel ◽  
Jean-Louis Clément ◽  
Agnès Muller ◽  
Marcel Culcasi ◽  
Sylvia Pietri
Keyword(s):  
Acidic Ph ◽  
Highly Sensitive ◽  
Nmr Characterization ◽  
Low Toxic ◽  
Ph Probes

scholarly journals Cortical neurons exhibit diverse myelination patterns that scale between mouse brain regions and regenerate after demyelination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cody L. Call ◽  
Dwight E. Bergles
Keyword(s):  
Cortical Neurons ◽  
Regional Differences ◽  
Brain Regions ◽  
Axon Diameter ◽  
Neuronal Identity ◽  
Cortical Areas ◽  
Myelin Sheaths ◽  
Parvalbumin Interneurons ◽  
Selection Of

ABSTRACTAxons in the cerebral cortex show a broad range of myelin coverage. Oligodendrocytes establish this pattern by selecting a cohort of axons for myelination; however, the distribution of myelin on distinct neurons and extent of internode replacement after demyelination remain to be defined. Here we show that myelination patterns of seven distinct neuron subtypes in somatosensory cortex are influenced by both axon diameter and neuronal identity. Preference for myelination of parvalbumin interneurons was preserved between cortical areas with varying myelin density, suggesting that regional differences in myelin abundance arises through local control of oligodendrogenesis. By imaging loss and regeneration of myelin sheaths in vivo we show that myelin distribution on individual axons was altered but overall myelin content on distinct neuron subtypes was restored. Our findings suggest that local changes in myelination are tolerated, allowing regenerated oligodendrocytes to restore myelin content on distinct neurons through opportunistic selection of axons.

scholarly journals Hippocampal Interneurons are Required for Trace Eyeblink Conditioning in Mice

2021 ◽  
Author(s):  
Wei-Wei Zhang ◽  
Rong-Rong Li ◽  
Jie Zhang ◽  
Jie Yan ◽  
Qian-Hui Zhang ◽  
...  
Keyword(s):  
Eyeblink Conditioning ◽  
Pyramidal Cells ◽  
Conditioned Eyeblink ◽  
Cellular Mechanisms ◽  
Sustained Activity ◽  
Early Acquisition ◽  
Freely Moving ◽  
Trace Eyeblink Conditioning

AbstractWhile the hippocampus has been implicated in supporting the association among time-separated events, the underlying cellular mechanisms have not been fully clarified. Here, we combined in vivo multi-channel recording and optogenetics to investigate the activity of hippocampal interneurons in freely-moving mice performing a trace eyeblink conditioning (tEBC) task. We found that the hippocampal interneurons exhibited conditioned stimulus (CS)-evoked sustained activity, which predicted the performance of conditioned eyeblink responses (CRs) in the early acquisition of the tEBC. Consistent with this, greater proportions of hippocampal pyramidal cells showed CS-evoked decreased activity in the early acquisition of the tEBC. Moreover, optogenetic suppression of the sustained activity in hippocampal interneurons severely impaired acquisition of the tEBC. In contrast, suppression of the sustained activity of hippocampal interneurons had no effect on the performance of well-learned CRs. Our findings highlight the role of hippocampal interneurons in the tEBC, and point to a potential cellular mechanism subserving associative learning.

734 A novel NQO1 specific anti-tumor agent, SBSC-S3001, selectively regresses the growth of tumors with high NQO1 expression

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A778-A778
Author(s):  
Minhyuk Yun ◽  
Goo-Young Kim ◽  
Sang Woo Jo ◽  
Changhoon In ◽  
Gyu-Young Moon ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Cancer Cells ◽  
Poor Prognosis ◽  
High Expression ◽  
List Type ◽  
Dependent Manner ◽  
Breast Cancers ◽  
Quinone Oxidoreductase ◽  
Key Enzymes

BackgroundNAD(P)H-quinone oxidoreductase 1 (NQO1) is a cytosolic two-electron oxidoreductase overexpressed in many types of cancers, including breast cancer, pancreatic cancer, colorectal cancer, cholangiocarcinoma, uterine cervical cancer, melanoma, and lung cancer.1Up-regulation of NQO1 protects cells from oxidative stress and various cytotoxic quinones and is associated with late clinical stage, poor prognosis and lymph node metastasis.2 3 NQO1 increases stability of HIF-1α protein, which has been implicated in survival, proliferation, and malignance of cancer.1 Therefore, accumulating evidences suggest NQO1 as a promising therapeutic target for cancer. Accordingly, we have characterized the effect of a novel synthetic NQO1 substrate SBSC-S3001, and demonstrated its selective cytotoxic effects in cancer cells with high expression of NQO1.MethodsIn vitro cytotoxicity was determined by sulforhodamine B (SRB) assay in cancer cells with high NQO1 expression and CRISPR-mediated NQO1 knockout cells. The effect of SBSC-S3001 on the energy metabolism pathway was evaluated by western blot analysis of metabolism associated proteins from NQO1-overexpressed cancer cells treated with the compound for 24 hours. In vivo anti-tumor activity was evaluated in MC38 syngeneic and DLD-1 orthotopic mice models.ResultsSBSC-S3001 exhibited selective cytotoxicity in cancer cells with high expression of NQO1 in a dose-dependent manner. The cytotoxicity was observed in both normoxia and hypoxia conditions, correlating with the energy metabolism, mitochondrial biogenesis, and cancer proliferative pathways. Also, stronger cytotoxicity was observed in NQO1-overexpressed cancer cells treated with SBSC-S3001 compared to beta-lapachone and analogue treatment.4 When evaluated in vivo, SBSC-S3001 effectively inhibited the growth of syngeneic and orthotopic tumors when administered as a monotherapy. SBSC-S3001 treatment associated with reduction in key enzymes of the glycolytic pathway (LDHa and GAPDH) and HIF-1α and increase in levels of mitochondrial oxidative phosphorylation (OXPHOS) complex.ConclusionsTreatment of SBSC-S3001, a novel, NQO1-specific substrate reduces HIF-1α and key enzymes associated with glycolysis and suppresses the growth of tumors overexpressing NQO1. Further characterization of SBSC-S3001 as a novel metabolic anti-cancer agent for cancers with NQO1 overexpression is warranted.Ethics ApprovalThe study was approved by Samyang Biopharmaceuticals Institution’s Ethics Board, approval number SYAU2031.ReferencesOh ET, Kim JW, Kim JMet. al., NQO1 inhibits proteasome-mediated degradation of HIF-1α. Nat Commun 2016; 14:13593.Ma, Y. et al. NQO1 overexpression is associated with poor prognosis in squamous cell carcinoma of the uterine cervix. BMC Cancer 2014;14: 414Yang, Y. et al. Clinical implications of high NQO1 expression in breast cancers. J. Exp. Clin. Cancer Res 2014;33:144.Yang Y, Zhou X, Xu M, et al., β-lapachone suppresses tumour progression by inhibiting epithelial-to-mesenchymal transition in NQO1-positive breast cancers. Sci Rep 2017;7:2681.

Optically pumped magnetometers enable a new level of biomagnetic measurements

2020 ◽  
Vol 9 (5) ◽  
pp. 247-251
Author(s):  
Tilmann Sander ◽  
Anna Jodko-Władzińska ◽  
Stefan Hartwig ◽  
Rüdiger Brühl ◽  
Thomas Middelmann
Keyword(s):  
Quantum Interference ◽  
High Sensitivity ◽  
High Temporal Resolution ◽  
Optically Pumped ◽  
New Class ◽  
Magnetic Shields ◽  
Highly Sensitive ◽  
Electric And Magnetic Fields ◽  
Auditory Evoked Fields

AbstractThe electrophysiological activities in the human body generate electric and magnetic fields that can be measured noninvasively by electrodes on the skin, or even, not requiring any contact, by magnetometers. This includes the measurement of electrical activity of brain, heart, muscles and nerves that can be measured in vivo and allows to analyze functional processes with high temporal resolution. To measure these extremely small magnetic biosignals, traditionally highly sensitive superconducting quantum-interference devices have been used, together with advanced magnetic shields. Recently, they have been complemented in usability by a new class of sensors, optically pumped magnetometers (OPMs). These quantum sensors offer a high sensitivity without requiring cryogenic temperatures, allowing the design of small and flexible sensors for clinical applications. In this letter, we describe the advantages of these upcoming OPMs in two exemplary applications that were recently carried out at Physikalisch-Technische Bundesanstalt (PTB): (1) magnetocardiography (MCG) recorded during exercise and (2) auditory-evoked fields registered by magnetoencephalography.

scholarly journals Real-Time In Vivo Bioluminescent Imaging for Evaluating the Efficacy of Antibiotics in a Rat Staphylococcus aureus Endocarditis Model

2005 ◽  
Vol 49 (1) ◽  
pp. 380-387 ◽  
Author(s):  
Yan Q. Xiong ◽  
Julie Willard ◽  
Jagath L. Kadurugamuwa ◽  
Jun Yu ◽  
Kevin P. Francis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Imaging System ◽  
Bioluminescent Imaging ◽  
Vancomycin Therapy ◽  
Treatment Groups ◽  
Highly Sensitive ◽  
Relevant Animal Model ◽  
And Control

ABSTRACT Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bioluminescently engineered, biofilm-positive S. aureus strain was used to evaluate real-time antibiotic efficacy directly. This strain was vancomycin and cefazolin susceptible but gentamicin resistant. Bioluminescence was detected and quantified daily in antibiotic-treated and control animals with IE, using a highly sensitive in vivo imaging system (IVIS). Persistent and increasing cardiac bioluminescent signals (BLS) were observed in untreated animals. Three days of vancomycin therapy caused significant reductions in both cardiac BLS (>10-fold versus control) and S. aureus densities in cardiac vegetations (P < 0.005 versus control). However, 3 days after discontinuation of vancomycin therapy, a greater than threefold increase in cardiac BLS was observed, indicating relapsing IE (which was confirmed by quantitative culture). Cefazolin resulted in modest decreases in cardiac BLS and bacterial densities. These microbiologic and cardiac BLS differences during therapy correlated with a longer time-above-MIC for vancomycin (>12 h) than for cefazolin (∼4 h). Gentamicin caused neither a reduction in cardiac S. aureus densities nor a reduction in BLS. There were significant correlations between cardiac BLS and S. aureus densities in vegetations in all treatment groups. These data suggest that bioluminescent imaging provides a substantial advance in the real-time monitoring of the efficacy of therapy of invasive S. aureus infections in live animals.

Intracellular Features Predicted by Extracellular Recordings in the Hippocampus In Vivo

2000 ◽  
Vol 84 (1) ◽  
pp. 390-400 ◽  
Author(s):  
Darrell A. Henze ◽  
Zsolt Borhegyi ◽  
Jozsef Csicsvari ◽  
Akira Mamiya ◽  
Kenneth D. Harris ◽  
...  
Keyword(s):  
Extracellular Recordings
Sign in / Sign up

Export Citation Format

Share Document