‘Weightless’ Micro-electrodes for recording Extracellular Unit Action Potentials from the Central Nervous System

Nature ◽  
1960 ◽  
Vol 186 (4720) ◽  
pp. 246-247 ◽  
Author(s):  
B. DELISLE BURNS ◽  
J. G. ROBSON
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Action Potentials ◽  
The Central Nervous System ◽  
Unit Action

scholarly journals Reduced motoneuron excitability in a rat model of sepsis

2013 ◽  
Vol 109 (7) ◽  
pp. 1775-1781 ◽  
Author(s):  
Paul Nardelli ◽  
Jaffar Khan ◽  
Randall Powers ◽  
Tim C. Cope ◽  
Mark M. Rich
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Intensive Care ◽  
Motor Unit ◽  
Action Potentials ◽  
Cecal Ligation ◽  
Membrane Properties ◽  
Whole Body ◽  
Repetitive Firing ◽  
The Central Nervous System

Many critically ill patients in intensive care units suffer from an infection-induced whole body inflammatory state known as sepsis, which causes severe weakness in patients who survive. The mechanisms by which sepsis triggers intensive care unit-acquired weakness (ICUAW) remain unclear. Currently, research into ICUAW is focused on dysfunction of the peripheral nervous system. During electromyographic studies of patients with ICUAW, we noticed that recruitment was limited to few motor units, which fired at low rates. The reduction in motor unit rate modulation suggested that functional impairment within the central nervous system contributes to ICUAW. To understand better the mechanism underlying reduced firing motor unit firing rates, we moved to the rat cecal ligation and puncture model of sepsis. In isoflurane-anesthetized rats, we studied the response of spinal motoneurons to injected current to determine their capacity for initiating and firing action potentials repetitively. Properties of single action potentials and passive membrane properties of motoneurons from septic rats were normal, suggesting excitability was normal. However, motoneurons exhibited striking dysfunction during repetitive firing. The sustained firing that underlies normal motor unit activity and smooth force generation was slower, more erratic, and often intermittent in septic rats. Our data are the first to suggest that reduced excitability of neurons within the central nervous system may contribute to ICUAW.

An electrophysiological analysis of extra-axonal sodium and potassium concentrations in the central nervous system of the cockroach (Periplaneta americana L.)

1975 ◽  
Vol 63 (3) ◽  
pp. 801-811
Author(s):  
M. V. Thomas ◽  
J. E. Treherne
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Action Potentials ◽  
Periplaneta Americana ◽  
Sodium Concentration ◽  
Blood Potassium ◽  
The Central Nervous System ◽  
Sucrose Gap ◽  
Sodium And Potassium

Simultaneous intracellular and sucrose-gap recordings showed, in contrast to previous findings, that the electrical parameters of giant axons were similar to intact and desheathed connectives bathed with the ‘extracellular Ringer’ of Yamasaki & Narahashi. This implies that the extra-axonal sodium concentration, in situ, is likely to be lower than had been previously supposed. Axonal responses showed that, despite the high blood concentration of 24–2 mM-K+ measured by flame photometry, the effective concentration in the blood was 10–15 mM-K+ which corresponds to the measurements made with potassium-selective electrodes. The activity of the blood potassium ions caused a marked reduction in the amplitude of the action potentials following surgical desheathing or disruption of the blood-brain barrier with hypertonic urea. It is suggested that a regulatory mechanism exists in the central nervous system which counteracts the effects of the high blood potassium level.

scholarly journals Slack, Slick, and Sodium-Activated Potassium Channels

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Leonard K. Kaczmarek
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Potassium Channels ◽  
Ampa Receptors ◽  
Neuronal Plasticity ◽  
Action Potentials ◽  
Neurotransmitter Receptors ◽  
Learning And Development ◽  
Intellectual Function ◽  
The Central Nervous System

The Slack and Slick genes encode potassium channels that are very widely expressed in the central nervous system. These channels are activated by elevations in intracellular sodium, such as those that occur during trains of one or more action potentials, or following activation of nonselective cationic neurotransmitter receptors such as AMPA receptors. This review covers the cellular and molecular properties of Slack and Slick channels and compares them with findings on the properties of sodium-activated potassium currents (termed KNa currents) in native neurons. Human mutations in Slack channels produce extremely severe defects in learning and development, suggesting that KNa channels play a central role in neuronal plasticity and intellectual function.

Voltage-gated sodium channels and pain

e-Neuroforum ◽  
2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Carla Nau ◽  
Enrico Leipold
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sodium Channels ◽  
Action Potentials ◽  
Afferent Pathways ◽  
Voltage Gated ◽  
Voltage Gated Sodium Channels ◽  
The Central Nervous System

AbstractPainful stimuli are detected by specialized neurons, nociceptors, and are translated into action potentials, that are conducted along afferent pathways into the central nervous system, where they are conceived as pain. Voltage-gated sodium channels (Na

scholarly journals The neuropeptide SMYamide, a SIFamide paralog, is expressed by salivary gland innervating neurons in the American cockroach and likely functions as a hormone

2020 ◽  
Author(s):  
Jan A. Veenstra
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Salivary Gland ◽  
Salivary Glands ◽  
Action Potentials ◽  
American Cockroach ◽  
Endocrine Function ◽  
Peripheral Tissues ◽  
The Central Nervous System

AbstractThe SMYamide genes are paralogs of the SIFamide genes and code for neuropeptides that are structurally similar to SIFamide. In the American cockroach, Periplanea americana, the SMYamide gene is specifically expressed in the SN2 neurons that innervate the salivary glands and are known to produce action potentials during feeding. The innervation of the salivary glands by the SN2 neurons is such that one has to expect that on activation of these neurons significant amounts of SMYamide will be released into the hemolymph, thus suggesting that SMYamide also functions as a hormone. In the Periplaneta genome there are two putative SIFamide receptors and these are both expressed not only in the central nervous system and the salivary gland, but also in the gonads and other peripheral tissues. This reinforces the hypothesis that SMYamide also has an endocrine function in this species.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Emigration of neutrophils in the central nervous system

1983 ◽  
Vol 41 ◽  
pp. 788-789
Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
White Blood Cells ◽  
Arterial Perfusion ◽  
E Coli ◽  
Intracisternal Injection ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

Mammalian Bone Marrow Acetylcholinesterase

1982 ◽  
Vol 40 ◽  
pp. 44-45
Author(s):  
Ezzatollah Keyhani
Keyword(s):  
Central Nervous System ◽  
Bone Marrow ◽  
Nervous System ◽  
Common Property ◽  
Extracellular Medium ◽  
The Central Nervous System ◽  
The Common ◽  
Mammalian Bone

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.

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