Depression by magnesium ion of neuronal excitability in tissue cultures of central nervous system

1977 ◽  
Vol 55 (3) ◽  
pp. 367-372 ◽  
Author(s):  
J. M. Wojtowicz ◽  
K. C. Marshall ◽  
W. J. Hendelman
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neuronal Excitability ◽  
Neuronal Membrane ◽  
Magnesium Ion ◽  
Tissue Cultures ◽  
Central Nervous System Tissue ◽  
Membrane Excitability ◽  
Antidromic Activation

Magesium ion (Mg2+) in concentrations of 5–10 mM has been used to block synaptic transmission in in vitro preparations of central nervous system tissue. We have used explants of mouse cerebellum grown in culture to test whether significant levels of direct depression of neuronal membrane excitability could occur in such experiments. Using thresholds for antidromic activation and iontophoretically applied glutamate as tests of excitability, potent depressions of membrane excitability were found using 5–10 mM Mg2+. The additive depressant effects of increased Ca2+ concentrations provided further evidence that the effects were largely on membrane excitability and not on transmitter release mechanisms.

Extracellular Magnesium Ion Modifies the Actions of Volatile Anesthetics in Area CA1 of Rat Hippocampus In Vitro 

2002 ◽  
Vol 96 (3) ◽  
pp. 681-687 ◽  
Author(s):  
Rika Sasaki ◽  
Koki Hirota ◽  
Sheldon H. Roth ◽  
Mitsuaki Yamazaki
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Hippocampal Slices ◽  
Volatile Anesthetics ◽  
Population Spike ◽  
Magnesium Ion ◽  
Excitatory Postsynaptic Potential ◽  
Aspartate Receptor ◽  
Postsynaptic Potential

Background Magnesium ion (Mg2+) is involved in important processes as modulation of ion channels, receptors, neurotransmitter release, and cell excitability in the central nervous system. Although extracellular Mg2+ concentration ([Mg2+]o) can be altered during general anesthesia, there has been no evidence for [Mg2+]o-dependent modification of anesthetic actions on neural excitability in central nervous system preparations. The purpose of current study was to determine whether the effects of volatile anesthetics are [Mg2+]o-dependent in mammalian central nervous system. Methods Extracellular electrophysiologic recordings from CA1 neurons in rat hippocampal slices were used to investigate the effects of [Mg2+]o and anesthetics on population spike amplitude and excitatory postsynaptic potential slope. Results The depression of population spike amplitudes and excitatory postsynaptic potential slopes by volatile anesthetics were significantly dependent on [Mg2+]o. The effects were attenuated in the presence of a constant [Mg2+]o/extracellular Ca2+ concentration ratio. However, neither N-methyl-d-aspartate receptor antagonists nor a non-N-methyl-d-aspartate receptor antagonist altered the [Mg2+]o-dependent anesthetic-induced depression of population spikes. Volatile anesthetics produced minimal effects on input-output (excitatory postsynaptic potential-population spike) relations or the threshold for population spike generation. The effects were not modified by changes in [Mg2+]o. In addition, the population spike amplitudes, elicited via antidromic (nonsynaptic) stimulation, were not influenced by [Mg2+]o in the presence of volatile anesthetics. Conclusions These results provide support that alteration of [Mg2+]o modifies the actions of volatile anesthetics on synaptic transmission and that the effects could be, at least in part, a result of presynaptic Ca2+ channel-related mechanisms.

HIV-1 INFECTION OF HUMAN FETAL ORGANOTYPIC CENTRAL NERVOUS SYSTEM TISSUE CULTURES

1989 ◽  
Vol 48 (3) ◽  
pp. 383
Author(s):  
W. D. Lyman ◽  
K. Tanaka ◽  
W. Hatch ◽  
M. Tricoche ◽  
Y. Kress ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Tissue Cultures ◽  
Central Nervous System Tissue ◽  
Hiv 1

scholarly journals Axonal Damage Induced by Invading T Cells in Organotypic Central Nervous System Tissue in vitro: Involvement of Microglial Cells

2006 ◽  
Vol 10 (3) ◽  
pp. 365-377 ◽  
Author(s):  
Ulrike Gimsa ◽  
Susanne VA. Peter ◽  
Kathrin Lehmann ◽  
Ingo Bechmann ◽  
Robert Nitsch
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
Axonal Damage ◽  
Microglial Cells ◽  
Central Nervous System Tissue

scholarly journals THE ENZYMATIC RESPONSE OF ASTROCYTES TO VARIOUS IONS IN VITRO

1964 ◽  
Vol 20 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Reinhard L. Friede
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Enzyme Activity ◽  
Succinic Dehydrogenase ◽  
Living Organism ◽  
Ion Concentration ◽  
Tissue Cultures ◽  
The Central Nervous System ◽  
Enzymatic Changes

The effect of environmental ion concentration on the enzyme activity of astrocytes was investigated in tissue cultures of rat cerebral cortex. It was found that the oxidative enzymatic activity (succinic dehydrogenase, DPN-diaphorase, and several other enzymes) of astrocytes depended on the concentration of NaCl in the environment. This response was not specific for NaCl, but was also elicited by MgCl2 and LiCl; the response was less consistent, and often questionable for KCl. However, only NaCl could elicit enzymatic changes in astrocytes at concentrations known to be present in a living organism. Astrocytes were the only cells which responded this way; it appeared that the foot-plates were particularly involved in the response since increase of enzyme activity occurred earlier in the foot-plates than in the perikarya. It was concluded that astrocytes are metabolically involved in the maintenance of the ionic and osmotic environment of the central nervous system, particularly in regard to the active transport of sodium.

Dispersion of central nervous system tumors

1974 ◽  
Vol 41 (6) ◽  
pp. 691-698 ◽  
Author(s):  
Ulrich Batzdorf ◽  
Vivian Gold
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Central Nervous System Tumors ◽  
Tissue Cultures ◽  
Human Central Nervous System ◽  
Content Type ◽  
Nervous System Tumors ◽  
Mechanical Factors ◽  
Made In

✓ The phenomenon of tumor dispersion through cerebrospinal fluid is discussed in relation to observations made in tissue cultures of human central nervous system tumors. Satellite colony formation was observed in cultures of tumors that tend to spread through the CSF. Abnormalities of the tumor cell surface, particularly a reduction of cell-to-cell adhesiveness, probably are important. Although mechanical factors contribute to the formation of both CSF metastases and in vitro satellites, they do not offer a sufficient explanation for these phenomena.

Confocal laser microscopy of impregnated central nervous system tissue

1988 ◽  
Vol 46 ◽  
pp. 94-95
Author(s):  
J.N. Turner ◽  
M. Siemens ◽  
D. Szarowski ◽  
D.N. Collins
Keyword(s):  
Electron Microscopy ◽  
Central Nervous System ◽  
Nervous System ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Confocal Laser ◽  
High Contrast ◽  
Central Nervous System Tissue ◽  
Tissue Samples ◽  
Reflected Light

A classic preparation of central nervous system tissue (CNS) is the Golgi procedure popularized by Cajal. The method is partially specific as only a few cells are impregnated with silver chromate usualy after osmium post fixation. Samples are observable by light (LM) or electron microscopy (EM). However, the impregnation is often so dense that structures are masked in EM, and the osmium background may be undesirable in LM. Gold toning is used for a subtle but high contrast EM preparation, and osmium can be omitted for LM. We are investigating these preparations as part of a study to develop correlative LM and EM (particularly HVEM) methodologies in neurobiology. Confocal light microscopy is particularly useful as the impregnated cells have extensive three-dimensional structure in tissue samples from one to several hundred micrometers thick. Boyde has observed similar preparations in the tandem scanning reflected light microscope (TSRLM).

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

scholarly journals Beyond Oncological Hyperthermia: Physically Drivable Magnetic Nanobubbles as Novel Multipurpose Theranostic Carriers in the Central Nervous System

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2104 ◽  
Author(s):  
Eleonora Ficiarà ◽  
Shoeb Anwar Ansari ◽  
Monica Argenziano ◽  
Luigi Cangemi ◽  
Chiara Monge ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tumors ◽  
Ad Hoc ◽  
Superparamagnetic Iron Oxide ◽  
Conventional Radiotherapy ◽  
The Central Nervous System ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic Oxygen-Loaded Nanobubbles (MOLNBs), manufactured by adding Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on the surface of polymeric nanobubbles, are investigated as theranostic carriers for delivering oxygen and chemotherapy to brain tumors. Physicochemical and cyto-toxicological properties and in vitro internalization by human brain microvascular endothelial cells as well as the motion of MOLNBs in a static magnetic field were investigated. MOLNBs are safe oxygen-loaded vectors able to overcome the brain membranes and drivable through the Central Nervous System (CNS) to deliver their cargoes to specific sites of interest. In addition, MOLNBs are monitorable either via Magnetic Resonance Imaging (MRI) or Ultrasound (US) sonography. MOLNBs can find application in targeting brain tumors since they can enhance conventional radiotherapy and deliver chemotherapy being driven by ad hoc tailored magnetic fields under MRI and/or US monitoring.

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