The Distribution and Exchange of Inorganic Ions in the Central Nervous System of the Stick Insect Carausius Morosus

1965 ◽  
Vol 42 (1) ◽  
pp. 7-27
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Extracellular Fluid ◽  
Inorganic Ions ◽  
Stick Insect ◽  
Metabolic Inhibitors ◽  
Carausius Morosus ◽  
Intracellular Compartments ◽  
Extra Cellular Fluid ◽  
The Central Nervous System

1. The distribution and exchange of inorganic ions between the central and the haemolymph has been studied in the stick insect, Carausius morosus, by flame photometry and radioactive tracers. 2. The exchanges of labelled ions show rapid and slow components which correspond to extracellular and intracellular compartments within the central nervous system. 3. The uptake of sodium from the haemolymph and its concentration in the extra-cellular fluid is reduced in the presence of metabolic inhibitors. 4. The distribution between haemolymph and extracellular fluid of calcium and magnesium, and also of sodium in poisoned preparations, conforms to a Donnan equilibrium. The distribution of potassium, even in poisoned preparations, does not conform and it is suggested that the activity of this ion may be lower than in free solution. 5. The concentration of magnesium is appreciably greater in the extracellular than in the intracellular compartment. The possible role of magnesium in nervous transmission in this insect is discussed.

SYMPTOMATIC HYPONATREMIA IN ACUTE INFECTIONS OF THE CENTRAL NERVOUS SYSTEM

PEDIATRICS ◽  
1956 ◽  
Vol 18 (4) ◽  
pp. 604-613
Author(s):  
William L. Nyhan ◽  
Robert E. Cooke
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Hypertonic Saline ◽  
Water Intake ◽  
Extracellular Fluid ◽  
Water Intoxication ◽  
Extracellular Fluid Volume ◽  
Acute Infections ◽  
The Central Nervous System ◽  
Acute Hyponatremia

Acute hyponatremia has been noted on seven occasions in five patients with acute infections of the central nervous system. Symptoms were those of water intoxication and the response to the administration of hypertonic saline was prompt and dramatic. The hyponatremia appears to be due to acute expansion of the extracellular fluid volume in association with antidiuresis. Frequent determinations of the concentrations of electrolytes in the serum and prophylactic limitation of water intake are recommended as possible means of reducing mortality in disease of the central nervous system.

The Metabolism of Acetylcholine in the Intact Central Nervous System of An Insect (Periplaneta Americana L.)

1965 ◽  
Vol 43 (3) ◽  
pp. 441-454
Author(s):  
J. E. TREHERNE ◽  
D. S. SMITH
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Cholinergic System ◽  
Periplaneta Americana ◽  
Extracellular Fluid ◽  
Fibrous Layer ◽  
Nerve Sheath ◽  
The Central Nervous System ◽  
Hydrolysis Of

1. A very rapid metabolism of 3H-labelled acetylcholine has been demonstrated in the intact abdominal nerve cord. It has been shown that the cholinesterase system is effective in drastically reducing the concentration of acetylcholine in the extracellular fluid of the terminal abdominal ganglion with bathing solutions of up to IO-2M acetylcholine. 2. Evidence has been obtained which indicates that an appreciable hydrolysis of acetylcholine occurs at the periphery of the nerve cord. This effect is correlated with the electronmicroscopic demonstration of regions of eserine-sensitive cholinesterase located on glial membranes in the periphery of ganglia and connectives. It is suggested that some hydrolysis of extraneous acetylcholine may occur in the fibrous layer of the nerve sheath as a result of an accumulation of diffusible acetylcholinesterase in this region. 3. The results are discussed in relation to the possible involvement of the conventional cholinergic system in synaptic transmission in the central nervous system of this insect.

scholarly journals NextGen Brain Microdialysis: Applying Modern Metabolomics Technology to the Analysis of Extracellular Fluid in the Central Nervous System

2015 ◽  
Vol 1 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Chi-Ya Kao ◽  
Elmira Anderzhanova ◽  
John M. Asara ◽  
Carsten T. Wotjak ◽  
Christoph W. Turck
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Extracellular Fluid ◽  
Brain Microdialysis ◽  
The Central Nervous System

scholarly journals Tight Junction Modulating Bioprobes for Drug Delivery System to the Brain: A Review

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1236
Author(s):  
Keisuke Tachibana ◽  
Yumi Iwashita ◽  
Erika Wakayama ◽  
Itsuki Nishino ◽  
Taiki Nishikaji ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Central Nervous System ◽  
Endothelial Cells ◽  
Nervous System ◽  
Extracellular Fluid ◽  
Transport Systems ◽  
Brain Extracellular Fluid ◽  
The Central Nervous System ◽  
Polarized Transport ◽  
The Brain

The blood-brain barrier (BBB), which is composed of endothelial cells, pericytes, astrocytes, and neurons, separates the brain extracellular fluid from the circulating blood, and maintains the homeostasis of the central nervous system (CNS). The BBB endothelial cells have well-developed tight junctions (TJs) and express specific polarized transport systems to tightly control the paracellular movements of solutes, ions, and water. There are two types of TJs: bicellular TJs (bTJs), which is a structure at the contact of two cells, and tricellular TJs (tTJs), which is a structure at the contact of three cells. Claudin-5 and angulin-1 are important components of bTJs and tTJs in the brain, respectively. Here, we review TJ-modulating bioprobes that enable drug delivery to the brain across the BBB, focusing on claudin-5 and angulin-1.

HYPERTONIC DEHYDRATION IN INFANCY

PEDIATRICS ◽  
1956 ◽  
Vol 17 (2) ◽  
pp. 171-183 ◽  
Author(s):  
William B. Weil ◽  
William M. Wallace
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Water Deficit ◽  
Water Retention ◽  
Clinical Signs ◽  
Extracellular Fluid ◽  
Body Water ◽  
Dilute Solutions ◽  
The Central Nervous System ◽  
Rapid Adjustment

Dehydration, biochemically characterized by increased concentrations of sodium and chloride in the extracellular fluid, is a frequent result of diarrhea in infants. The genesis of the hypernatremia and hyperchloremia lies in the relatively greater expenditure of water than electrolyte via skin, lungs, stool and urine. The significance of these events in terms of distribution of body water and cation are discussed. The water deficit in these infants is primarily intracellular. Cation deficits are minimal. The majority of infants with this type of dehydration present certain clinical signs that should serve to make the clinician aware of the abnormality of concentration. These infants show varying degrees of depression of central nervous system varying from lethargy to coma. Convulsions are frequently observed during the course of the disturbance. While dehydration, as measured by water retention during recovery, is invariably present, the traditional signs of water deficit are deceptively absent. Dilute solutions of electrolyte are indicated in repair. Rapid adjustment, however, of the concentration abnormality appears to accentuate the central nervous system disturbance. Repair is best carried out in a leisurely manner over a 2- to 3-day period.

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