Training-Induced Changes in Neural Function

2003 ◽  
Vol 31 (2) ◽  
pp. 61-67 ◽  
Author(s):  
Per Aagaard
Keyword(s):  
Neural Function ◽  
Induced Changes

Epigenetic regulation of genes in learning and memory

2010 ◽  
Vol 48 ◽  
pp. 263-274 ◽  
Author(s):  
Tania L. Roth ◽  
Eric D. Roth ◽  
J. David Sweatt
Keyword(s):  
Learning And Memory ◽  
Cognitive Dysfunction ◽  
Epigenetic Regulation ◽  
Memory Formation ◽  
Covalent Modification ◽  
Gene Activity ◽  
Neural Function ◽  
Post Translational Modifications ◽  
Novel Approach ◽  
Induced Changes

Rapid advances in the field of epigenetics are revealing a new way to understand how we can form and store strong memories of significant events in our lives. Epigenetic modifications of chromatin, namely the post-translational modifications of nuclear proteins and covalent modification of DNA that regulate gene activity in the CNS (central nervous system), continue to be recognized for their pivotal role in synaptic plasticity and memory formation. At the same time, studies are correlating aberrant epigenetic regulation of gene activity with cognitive dysfunction prevalent in CNS disorders and disease. Epigenetic research, then, offers not only a novel approach to understanding the molecular transcriptional mechanisms underlying experience-induced changes in neural function and behaviour, but potential therapeutic treatments aimed at alleviating cognitive dysfunction. In this chapter, we discuss data regarding epigenetic marking of genes in adult learning and memory formation and impairment thereof, as well as data showcasing the promise for manipulating the epigenome in restoring memory capacity.

scholarly journals Chronic sustained and intermittent hypoxia reduce function of ATP-sensitive potassium channels in nucleus of the solitary tract

2008 ◽  
Vol 295 (5) ◽  
pp. R1555-R1562 ◽  
Author(s):  
Weirong Zhang ◽  
Flávia R. Carreño ◽  
J. Thomas Cunningham ◽  
Steve W. Mifflin
Keyword(s):  
Intermittent Hypoxia ◽  
Neuronal Excitability ◽  
Reversal Potential ◽  
Outward Current ◽  
Second Order ◽  
Neural Function ◽  
Solitary Tract ◽  
Carotid Bodies ◽  
Bath Application ◽  
Induced Changes

Activation of neuronal ATP-sensitive potassium (KATP) channels is an important mechanism that protects neurons and conserves neural function during hypoxia. We investigated hypoxia (bath gassed with 95% N2-5% CO2 vs. 95% O2-5% CO2 in control)-induced changes in KATP current in second-order neurons of peripheral chemoreceptors in the nucleus of the solitary tract (NTS). Hypoxia-induced KATP currents were compared between normoxic (Norm) rats and rats exposed to 1 wk of either chronic sustained hypoxia (CSH) or chronic intermittent hypoxia (CIH). Whole cell recordings of NTS second-order neurons identified after 4-(4-(dihexadecylamino)styryl)- N-methylpyridinium iodide (DiA) labeling of the carotid bodies were obtained in a brain stem slice. In Norm cells ( n = 9), hypoxia (3 min) induced an outward current of 12.7 ± 1.1 pA with a reversal potential of −73 ± 2 mV. This current was completely blocked by the KATP channel blocker tolbutamide (100 μM). Bath application of the KATP channel opener diazoxide (200 μM, 3 min) evoked an outward current of 21.8 ± 5.8 pA ( n = 6). Hypoxia elicited a significantly smaller outward current in both CSH (5.9 ± 1.4 pA, n = 11; P < 0.01) and CIH (6.8 ± 1.7 pA, n = 6; P < 0.05) neurons. Diazoxide elicited a significantly smaller outward current in CSH (3.9 ± 1.0 pA, n = 5; P < 0.05) and CIH (2.9 ± 0.9 pA, n = 3; P < 0.05) neurons. Western blot analysis showed reduced levels of KATP potassium channel subunits Kir6.1 and Kir6.2 in the NTS from CSH and CIH rats. These results suggest that hypoxia activates KATP channels in NTS neurons receiving monosynaptic chemoreceptor afferent inputs. Chronic exposure to either sustained or intermittent hypoxia reduces KATP channel function in NTS neurons. This may represent a neuronal adaptation that preserves neuronal excitability in crucial relay neurons in peripheral chemoreflex pathways.

Preservation of neural function in the perinate by high PGE2 levels acting via EP2 receptors

2000 ◽  
Vol 89 (2) ◽  
pp. 777-784 ◽  
Author(s):  
Taline Najarian ◽  
Pierre Hardy ◽  
Xin Hou ◽  
Julie Lachapelle ◽  
Anjali Doke ◽  
...  
Keyword(s):  
Nervous Tissue ◽  
Receptor Agonist ◽  
Combined Treatment ◽  
Perinatal Period ◽  
Neural Function ◽  
Blood Flows ◽  
Newborn Piglets ◽  
Hypoxic Episode ◽  
Synthase Inhibitor ◽  
Induced Changes

Despite increasingly frequent and longer lasting hypoxic episodes during progressive labor, the neonate is alert and vigorous at birth. We investigated whether high levels of PGs during the perinatal period assist in preserving neural function after such “stressful” hypoxic events. Visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded before and 45 min after mild moderate asphyxic hypoxia (two 4-min asphyxic-hypoxic periods induced by interrupting ventilation at 8-min intervals) in newborn piglets <12 h old treated or not treated with inhibitors of PG synthase (ibuprofen or diclofenac) with or without PG analogs. At 45 min after the hypoxic episode, P2 and b-wave amplitudes were slightly decreased and latencies were delayed. These changes in the VEP and ERG returned to near normal by 120 min. Ibuprofen and diclofenac decreased brain and retinal PG levels and markedly intensified 45 min after hypoxia-induced changes in VEP and ERG, but cerebral and retinal blood flows improved. Combined treatment with PG synthase inhibitor in combination with 16,16-dimethyl-PGE2 (a PGE2 analog), but not with PGI2 and PGF2α analogs, and in combination with the EP2 receptor agonist butaprost (but not EP1 or EP3 agonists), prevented ibuprofen- and diclofenac-aggravated postasphyxia electrophysiological changes. In conclusion, high levels of PGE2 in nervous tissue, via actions on EP2 receptors, seem to contribute to preservation of neural function in the perinate subjected to frequent hypoxic events.

scholarly journals Transcriptomics-informed large-scale cortical model captures topography of pharmacological neuroimaging effects of LSD

2021 ◽  
Author(s):  
Joshua B. Burt ◽  
Katrin H. Preller ◽  
Murat Demirtaş ◽  
Jie Lisa Ji ◽  
John H. Krystal ◽  
...  
Keyword(s):  
Large Scale ◽  
Physiological State ◽  
Neural Function ◽  
Topographic Effects ◽  
Cortical Model ◽  
Individual Subject ◽  
Brain Physiology ◽  
Experiential Effects ◽  
Induced Changes ◽  
Serotonin 2A

AbstractPsychoactive drugs can transiently perturb brain physiology while preserving brain structure. The role of physiological state in shaping neural function can therefore be investigated through neuroimaging of pharmacologically-induced effects. This paradigm has revealed that neural and experiential effects of lysergic acid diethylamide (LSD) are attributable to its agonist activity at the serotonin-2A receptor. Here, we integrate brainwide transcriptomics with biophysically-based large-scale circuit modeling to simulate acute neuromodulatory effects of LSD on human cortical dynamics. Our model captures the topographic effects of LSD-induced changes in cortical BOLD functional connectivity. These findings suggest that serotonin-2A-mediated modulation of pyramidal cell gain is the circuit mechanism through which LSD alters cortical functional topography. Individual-subject fitting reveals that the model captures patterns of individual neural differences in drug response that predict altered states of consciousness. This work establishes a framework for linking molecular-level manipulations to salient changes in brain function, with implications for precision medicine.

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

Drug Induced Changes in Cell Organelles

1968 ◽  
Vol 26 ◽  
pp. 110-111
Author(s):  
Sarah A. Luse
Keyword(s):  
Clinical Medicine ◽  
Cell Organelles ◽  
Riboflavin Deficiency ◽  
Drug Induced ◽  
New Era ◽  
Health And Disease ◽  
In The Beginning ◽  
Cellular Pathology ◽  
Induced Changes ◽  
The Impact

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Immunogold localization of calmodulin in root caps of the maize Cultivar Merit

1990 ◽  
Vol 48 (3) ◽  
pp. 674-675
Author(s):  
P.T. Nguyen ◽  
C. Uphoff ◽  
C.L. Stinemetz
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Primary Role ◽  
Immunogold Localization ◽  
Root Tips ◽  
Electrical Currents ◽  
Considerable Evidence ◽  
Maize Cultivar ◽  
Gravity Response ◽  
Induced Changes

Considerable evidence suggest that the calcium-binding protein calmodulin (CaM) may mediate calcium action and/or transport important in the gravity response of plants. Calmodulin is present in both shoots and roots and is capable of regulating calcium transport in plant vesicles. In roots calmodulin is concentrated in the tip, the gravisensing region of the root; and is reported to be closely associated with amyloplasts, organelles suggested to play a primary role in gravi-perception. Inhibitors of CaM such as chlorpromazine, calmidazolium, and compound 48/80 interfere with the gravitropic response of both snoots and roots. The magnitude of the inhibition corresponded well with the extent to which the drug binds to endogenous CaM. Compound 48/80 and calmidazolium block gravi-induced changes in electrical currents across root tips, a phenomenon thought to be associated with the sensing of the gravity stimulus.In this study, we have investigated the subcellular distribution of CaM in graviresponsive and non-graviresponsive root caps of the maize cultivar Merit.

Identifying groups of airborne particles by ordination

1994 ◽  
Vol 52 ◽  
pp. 856-857
Author(s):  
M. Shlepr ◽  
C. M. Vicroy
Keyword(s):  
Elemental Analysis ◽  
Energy Dispersive Spectroscopy ◽  
Manufacturing Process ◽  
Spatial Representation ◽  
Airborne Particles ◽  
Common Source ◽  
Data Set ◽  
Microelectronics Industry ◽  
Induced Changes ◽  
Source Materials

The microelectronics industry is heavily tasked with minimizing contaminates at all steps of the manufacturing process. Particles are generated by physical and/or chemical fragmentation from a mothersource. The tools and macrovolumes of chemicals used for processing, the environment surrounding the process, and the circuits themselves are all potential particle sources. A first step in eliminating these contaminants is to identify their source. Elemental analysis of the particles often proves useful toward this goal, and energy dispersive spectroscopy (EDS) is a commonly used technique. However, the large variety of source materials and process induced changes in the particles often make it difficult to discern if the particles are from a common source.Ordination is commonly used in ecology to understand community relationships. This technique usespair-wise measures of similarity. Separation of the data set is based on discrimination functions. Theend product is a spatial representation of the data with the distance between points equaling the degree of dissimilarity.

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