Block of an insect central nervous system GABA receptor by cyclodiene and cyclohexane insecticides

1989 ◽  
Vol 237 (1286) ◽  
pp. 53-61 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Gaba Receptors ◽  
Chloride Channels ◽  
Periplaneta Americana ◽  
Chloride Concentration ◽  
Experimental Conditions ◽  
Order Of Magnitude ◽  
Insect Central Nervous System

The effects of a cyclodiene (endrin) and a cyclohexane (lindane) insecticide have been tested on γ -aminobutyric acid (GABA) receptors in the central nervous system of the cockroach ( Periplaneta americana ), by using electrophysiological methods and an in vitro functional receptor assay. In electrophysiological experiments on an identified motor neuron (D f ), endrin blocked the GABA response with a 50% inhibition concentration of 5.0 x 10 -7 M in a non-competitive manner. The actions of endrin were irreversible under the experimental conditions adopted. Increasing the intracellular chloride concentration reduced the effectiveness of endrin, whereas a change in the potassium concentration failed to influence the block by endrin of GABA responses. Lindane exhibited similar actions to endrin on insect GABA receptors, but was approximately an order of magnitude less effective. In a microsac preparation from cockroach nerve cords, endrin, at a concentration of 1.0 x 10 -5 M, completely blocked GABA-stimulated 36 C1 - uptake, whereas the same concentration of lindane was less potent, only blocking about 40% of uptake under similar conditions. Neither insecticide had any effect on L-glutamate-activated chloride channels. The results demonstrate that endrin and lindane block functional insect neuronal GABA receptors.

Blocking actions of heptachlor at an insect central nervous system GABA receptor

1990 ◽  
Vol 240 (1297) ◽  
pp. 97-106 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Gaba Receptors ◽  
Gaba Receptor ◽  
Periplaneta Americana ◽  
Heptachlor Epoxide ◽  
Potential Range ◽  
Functional Assays ◽  
Significant Difference ◽  
Insect Central Nervous System

The actions of the polychlorocycloalkane insecticide heptachlor, and its epoxide metabolite, were examined on GABA receptors in insects and vertebrates. Electrophysiological experiments on the cell body of the cockroach ( Periplaneta americana ) fast coxal depressor motor neuron ( D f ), and GABA-activated 36 Cl - uptake experiments on microsacs prepared from cockroach ventral nerve cords showed that both heptachlor and heptachlor epoxide blocked functional GABA receptors. The block appeared to be non-competitive and was voltage-independent over the membrane potential range —75 mV to —110 mV. There was no significant difference between the potencies of heptachlor and heptachlor epoxide in the functional assays for insect GABA receptors. Both compounds inhibited [ 35 S]- t -butylbicyclophosphorothionate ([ 35 S]TBPS) binding in insects and vertebrates. The findings provide further evidence for block of an insect GABA receptor/Cl - channel by the cyclodiene class of polychlorocycloalkanes, and reveal differences in the insecticide-[ 35 S]TBPS binding site interactions of insects and vertebrates.

The Nutrition of the Central Nervous System in the Cockroach Periplaneta Americana L

1960 ◽  
Vol 37 (3) ◽  
pp. 513-533
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Acid Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Total Activity ◽  
The Central Nervous System ◽  
14Co2 Production

1. 14C-labelled glucose injected into the cockroach was found to be rapidly converted to trehalose, only small amounts remaining in equilibrium with the disaccharide in the haemolymph. The entry of these sugars into the cockroach central nervous system was studied by following the increase in radioactivity within the abdominal nerve cord after the injection of radioactive glucose into the haemolymph. 2. The levels of radioactivity increased at closely similar rates in different parts of the abdominal nerve cord. 3. The influx of sugars into the nerve cord was calculated to be equivalent to 1.09 mM. glucose/l. of nerve cord water/min. 4. The greater part of the 14C entering the nerve cord originated from the trehalose, only about 7% being derived from the small amount of glucose in the haemolymph. The movement of the relatively small number of glucose molecules into the nerve cord occurred, nevertheless, at approximately 2.5 times the rate of the larger trehalose molecules. 5. Chromatographic analysis revealed that more than half of the absorbed 14C was incorporated as glutamic acid and glutamine in the nerve cord. Smaller amounts of glycogen, trehalose, glucose, aspartic acid and occasional traces of alanine were found. In the isolated nerve cord substantial amounts of alanine accumulated, the formation of the other amino acids being reduced. 14CO2 production in vitro was found, after 1 hr., to represent only about 1% of the total activity within the nerve cord. 6. The results demonstrate a linkage of carbohydrate and amino acid metabolism and represent circumstantial evidence for the presence of the tricarboxylic acid cycle enzymes in the central nervous system of this insect.

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.

scholarly journals Effects of Platelet-Rich Plasma on Cellular Populations of the Central Nervous System: The Influence of Donor Age

2021 ◽  
Vol 22 (4) ◽  
pp. 1725
Author(s):  
Diego Delgado ◽  
Ane Miren Bilbao ◽  
Maider Beitia ◽  
Ane Garate ◽  
Pello Sánchez ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cellular Response ◽  
Platelet Rich Plasma ◽  
Biological Response ◽  
In Vitro Models ◽  
Molecular Composition ◽  
Cellular Models ◽  
The Central Nervous System

Platelet-rich plasma (PRP) is a biologic therapy that promotes healing responses across multiple medical fields, including the central nervous system (CNS). The efficacy of this therapy depends on several factors such as the donor’s health status and age. This work aims to prove the effect of PRP on cellular models of the CNS, considering the differences between PRP from young and elderly donors. Two different PRP pools were prepared from donors 65–85 and 20–25 years old. The cellular and molecular composition of both PRPs were analyzed. Subsequently, the cellular response was evaluated in CNS in vitro models, studying proliferation, neurogenesis, synaptogenesis, and inflammation. While no differences in the cellular composition of PRPs were found, the molecular composition of the Young PRP showed lower levels of inflammatory molecules such as CCL-11, as well as the presence of other factors not found in Aged PRP (GDF-11). Although both PRPs had effects in terms of reducing neural progenitor cell apoptosis, stabilizing neuronal synapses, and decreasing inflammation in the microglia, the effect of the Young PRP was more pronounced. In conclusion, the molecular composition of the PRP, conditioned by the age of the donors, affects the magnitude of the biological response.

scholarly journals Design and In Vitro Study of a Dual Drug-Loaded Delivery System Produced by Electrospinning for the Treatment of Acute Injuries of the Central Nervous System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 848
Author(s):  
Luisa Stella Dolci ◽  
Rosaria Carmela Perone ◽  
Roberto Di Gesù ◽  
Mallesh Kurakula ◽  
Chiara Gualandi ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Delivery System ◽  
Synergistic Effects ◽  
In Vitro Release ◽  
Health Priorities ◽  
The Central Nervous System ◽  
Vitro Release ◽  
Dual Drug

Vascular and traumatic injuries of the central nervous system are recognized as global health priorities. A polypharmacology approach that is able to simultaneously target several injury factors by the combination of agents having synergistic effects appears to be promising. Herein, we designed a polymeric delivery system loaded with two drugs, ibuprofen (Ibu) and thyroid hormone triiodothyronine (T3) to in vitro release the suitable amount of the anti-inflammation and the remyelination drug. As a production method, electrospinning technology was used. First, Ibu-loaded micro (diameter circa 0.95–1.20 µm) and nano (diameter circa 0.70 µm) fibers were produced using poly(l-lactide) PLLA and PLGA with different lactide/glycolide ratios (50:50, 75:25, and 85:15) to select the most suitable polymer and fiber diameter. Based on the in vitro release results and in-house knowledge, PLLA nanofibers (mean diameter = 580 ± 120 nm) loaded with both Ibu and T3 were then successfully produced by a co-axial electrospinning technique. The in vitro release studies demonstrated that the final Ibu/T3 PLLA system extended the release of both drugs for 14 days, providing the target sustained release. Finally, studies in cell cultures (RAW macrophages and neural stem cell-derived oligodendrocyte precursor cells—OPCs) demonstrated the anti-inflammatory and promyelinating efficacy of the dual drug-loaded delivery platform.

scholarly journals Absence of the αvβ3 Integrin Dictates the Time-Course of Angiogenesis in the Hypoxic Central Nervous System: Accelerated Endothelial Proliferation Correlates with Compensatory Increases in α5β1 Integrin Expression

2010 ◽  
Vol 30 (5) ◽  
pp. 1031-1043 ◽  
Author(s):  
Longxuan Li ◽  
Jennifer V Welser ◽  
Richard Milner
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Time Course ◽  
Αvβ3 Integrin ◽  
Integrin Expression ◽  
Brain Endothelial Cells ◽  
Endothelial Proliferation ◽  
Β3 Integrin ◽  
Α5β1 Integrin

Cerebral angiogenesis is an important adaptive response to hypoxia. As the αvβ3 integrin is induced on angiogenic vessels in the ischemic central nervous system (CNS), and the suggested angiogenic role for this integrin in other systems, it is important to determine whether the αvβ3 integrin is an important mediator of cerebral angiogenesis. αvβ3 integrin expression was examined in a model of cerebral hypoxia, in which mice were subject to hypoxia (8% O2) for 0, 4, 7, or 14 days. Immunofluorescence and western blot analysis revealed that in the hypoxic CNS, αvβ3 integrin was strongly induced on angiogenic brain endothelial cells (BEC), along with its ligand vitronectin. In the hypoxia model, β3 integrin-null mice showed no obvious defect in cerebral angiogenesis. However, early in the angiogenic process, BEC in these mice showed an increased mitotic index that correlated closely with increased α5 integrin expression. In vitro experiments confirmed α5 integrin upregulation on β3 integrin-null BEC, which also correlated with increased BEC proliferation on fibronectin. These studies confirm hypoxic induction of αvβ3 integrin on angiogenic vessels, but suggest distinct roles for the BEC integrins αvβ3 and α5β1 in cerebral angiogenesis, with αvβ3 having a nonessential role, and α5β1 promoting BEC proliferation.

scholarly journals INFLUENCE OF ANESTHESIA ON EXPERIMENTAL NEUROTROPIC VIRUS INFECTIONS

1946 ◽  
Vol 84 (4) ◽  
pp. 277-292 ◽  
Author(s):  
S. Edward Sulkin ◽  
Christine Zarafonetis ◽  
Andres Goth
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Diethyl Ether ◽  
Cervical Region ◽  
Virus Infections ◽  
Ether Anesthesia ◽  
Neurotropic Virus ◽  
Experimental Infections

Anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (Eastern or Western type) or with the St. Louis encephalitis virus. No comparable effect is observed in experimental infections produced with rabies or poliomyelitis (Lansing) viruses. The neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ether anesthesia are caused by viruses which apparently are not destroyed by ether in vitro. Another striking difference between these two groups of viruses is their pathogenesis in the animal host; those which are inhibited in vivo by ether anesthesia tend to infect cells of the cortex, basal ganglia, and only occasionally the cervical region of the cord. On the other hand, those which are not inhibited in vivo by ether anesthesia tend to involve cells of the lower central nervous system and in the case of rabies, peripheral nerves. This difference is of considerable importance in view of the fact that anesthetics affect cells of the lower central nervous system only in very high concentrations. It is obvious from the complexity of the problem that no clear-cut statement can be made at this point as to the mechanism of the observed effect of ether anesthesia in reducing the mortality rate in certain of the experimental neurotropic virus infections. Important possibilities include a direct specific effect of diethyl ether upon the virus and a less direct effect of the anesthetic upon the virus through its alteration of the metabolism of the host cell.

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