scholarly journals The effect of hydrophobic gases on the nervous system of Daphnia magna

2021 ◽  
Author(s):  
K. Carlo Martín Robledo-Sánchez ◽  
J. C. Ruiz-Suárez
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Nitrous Oxide ◽  
Primary Site ◽  
Inert Gases ◽  
Hydrophobic Substances ◽  
Site Of Action ◽  
Invertebrate Animals ◽  
Intense Light

AbstractHundreds of hydrophobic substances: alkanes, alcohols, benzodiacepines, barbiturates, ethers and even gases, can induce General Anaesthesia (GA) in mammal animals. Moreover, it has been suggested that the primary site of action of such agents is on the spinal cord. Here, we investigate a scenario that is in double measure important to understand the mechanisms behind GA: its induction under water in invertebrate animals. We evaluate the capacity of xenon, nitrous oxide and krypton to suppress harmful sensations, provoked by intense light, in the crustacean D. magna. Due to the hydrophobic characteristics of those gases, we designed a special chamber to force them to dissolve in water at pressures up to to 50 atmospheres, whereas at the same time measure in real time the motility of the animals. Surprisingly, the aquatic animals are immobilized with xenon and nitrous oxide. Under this condition, they don’t respond to a noxious stimulus. Our results are crucial to understand the action of inert gases in GA and the role of the spinal cord.

scholarly journals The Role of Mcl-1 in Embryonic Neural Precursor Cell Apoptosis

2021 ◽  
Vol 9 ◽  
Author(s):  
Robert T. Flemmer ◽  
Sarah P. Connolly ◽  
Brittany A. Geizer ◽  
Joseph T. Opferman ◽  
Jacqueline L. Vanderluit
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Precursor Cell ◽  
Embryonic Lethality ◽  
Conditional Knockout ◽  
Neural Precursor ◽  
Null Mouse ◽  
Neural Precursor Cell ◽  
Thoracic Spinal Cord

Myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 protein, regulates neural precursor cell (NPC) survival in both the developing and adult mammalian nervous system. It is unclear when during the neurogenic period Mcl-1 becomes necessary for NPC survival and whether Bax is the sole pro-apoptotic target of Mcl-1. To address these questions, we used the nervous system-specific Nestin-Cre Mcl-1 conditional knockout mouse line (Mcl-1 CKO) to assess the anti-apoptotic role of Mcl-1 in developmental neurogenesis. Loss of Mcl-1 resulted in a wave of apoptosis beginning in the brainstem and cervical spinal cord at embryonic day 9.5 (E9.5) and in the forebrain at E10.5. Apoptosis was first observed ventrally in each region and spread dorsally over time. Within the spinal cord, apoptosis also spread in a rostral to caudal direction following the path of differentiation. Breeding the Mcl-1 CKO mouse with the Bax null mouse rescued the majority of NPC from apoptosis except in the dorsomedial brainstem and ventral thoracic spinal cord where only 50% were rescued. This demonstrates that Mcl-1 promotes NPC survival primarily by inhibiting the activation of Bax, but that Bax is not the sole pro-apoptotic target of Mcl-1 during embryonic neurogenesis. Interestingly, although co-deletion of Bax rescued the majority of NPC apoptosis, it resulted in embryonic lethality at E13, whereas conditional deletion of both Mcl-1 and Bax rescued embryonic lethality. In summary, this study demonstrates the widespread dependency on Mcl-1 during nervous system development.

Role of the sympathetic nervous system in CCl4 hepatotoxicity

1960 ◽  
Vol 198 (3) ◽  
pp. 669-676 ◽  
Author(s):  
Deane N. Calvert ◽  
Theodore M. Brody
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Sympathetic Nervous System ◽  
Liver Mitochondria ◽  
Central Vein ◽  
Fat Depots ◽  
Sympathetic Nervous ◽  
Adrenergic Blocking ◽  
Stimulation Of

An hypothesis is proposed which states that the characteristic hepatic changes seen after the administration of carbon tetrachloride are the result of stimulation of central sympathetic areas which produce a massive discharge of the peripheral sympathetic nervous system. Stimulation of the sympathetic supply to the blood vessels of the liver results in restriction of blood flow in the liver, leading to anoxia and the characteristic necrosis around the central vein of the hepatic lobule. Similarly the discharge causes the release of unesterified fatty acids from the peripheral fat depots and the consequent deposition of lipid in the liver. This hypothesis is based upon experimental evidence using the following physiologic and pharmacologic maneuvers: adrenergic blocking agents, pretreatment with reserpine, adrenalectomy and section of the spinal cord—all are effective to a greater or lesser extent in preventing the changes characteristically seen in oxidative phosphorylation of the liver mitochondria, activation of a Mg-dependent ATPase and deposition of lipid in the liver. Transection of the spinal cord is the most effective treatment and prevents entirely the characteristic changes seen in the above-mentioned functions.

scholarly journals Nitrous Oxide Impairs Axon Regeneration after Nervous System Injury in Male Rats

2019 ◽  
Vol 131 (5) ◽  
pp. 1063-1076
Author(s):  
Krista J. Stewart ◽  
Bermans J. Iskandar ◽  
Brenton M. Meier ◽  
Elias B. Rizk ◽  
Nithya Hariharan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Nitrous Oxide ◽  
Folic Acid ◽  
Functional Recovery ◽  
Axon Regeneration ◽  
Retinal Ganglion ◽  
Cord Injury

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Nitrous oxide can induce neurotoxicity. The authors hypothesized that exposure to nitrous oxide impairs axonal regeneration and functional recovery after central nervous system injury. Methods The consequences of single and serial in vivo nitrous oxide exposures on axon regeneration in four experimental male rat models of nervous system injury were measured: in vitro axon regeneration in cell culture after in vivo nitrous oxide administration, in vivo axon regeneration after sharp spinal cord injury, in vivo axon regeneration after sharp optic nerve injury, and in vivo functional recovery after blunt contusion spinal cord injury. Results In vitro axon regeneration 48 h after a single in vivo 70% N2O exposure is less than half that in the absence of nitrous oxide (mean ± SD, 478 ± 275 um; n = 48) versus 210 ± 152 um (n = 48; P < 0.0001). A single exposure to 80% N2O inhibits the beneficial effects of folic acid on in vivo axonal regeneration after sharp spinal cord injury (13.4 ± 7.1% regenerating neurons [n = 12] vs. 0.6 ± 0.7% regenerating neurons [n = 4], P = 0.004). Serial 80% N2O administration reverses the benefit of folic acid on in vivo retinal ganglion cell axon regeneration after sharp optic nerve injury (1277 ± 180 regenerating retinal ganglion cells [n = 7] vs. 895 ± 164 regenerating retinal ganglion cells [n = 7], P = 0.005). Serial 80% N2O exposures reverses the benefit of folic acid on in vivo functional recovery after blunt spinal cord contusion (estimate for fixed effects ± standard error of the estimate: folic acid 5.60 ± 0.54 [n = 9] vs. folic acid + 80% N2O 5.19 ± 0.62 [n = 7], P < 0.0001). Conclusions These data indicate that nitrous oxide can impair the ability of central nervous system neurons to regenerate axons after sharp and blunt trauma.

Leptin response to short-term fasting in sympathectomized men: role of the SNS

2003 ◽  
Vol 284 (3) ◽  
pp. E634-E640 ◽  
Author(s):  
Justin Y. Jeon ◽  
Vicki J. Harber ◽  
Robert D. Steadward
Keyword(s):  
Body Mass Index ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Short Term ◽  
Cord Injury ◽  
Before And After ◽  
Sympathetic Nervous ◽  
Plasma Leptin

We studied plasma leptin levels in six people with high-lesion spinal cord injury [SCI; body mass index (BMI) 25.9 ± 1.5 kg/m2, age 37 ± 3.0 yr] and six able-bodied (AB) controls (BMI 29.1 ± 1.9 kg/m2, age 35 ± 3.5 yr) before and after 12, 24, and 36 h of fasting. The plasma leptin levels significantly decreased during 36 h fasting by 48.8 ± 4.5% (pre: 11.3 ± 2.3, post: 6.2 ± 1.5 ng/ml) and 38.6 ± 7.9% (pre: 7.6 ± 5.0, post: 4.2 ± 1.0 ng/ml) in SCI and AB, respectively. Plasma leptin started to decrease at 24 h of fasting in the SCI group, whereas plasma leptin started to decrease at 12 h of fasting in the AB group. The current study demonstrated that plasma leptin decreased with fasting in both SCI and AB groups, with the leptin decrease being delayed in the SCI group. The delayed leptin response to fasting in the SCI group may be because of increased fat mass (%body fat, SCI: 33.8 ± 3.0, AB: 24.1 ± 2.9) and sympathetic nervous system dysfunction.

scholarly journals Heterotopic ossification after central nervous system injuries: understanding of pathogenesis

2018 ◽  
Vol 25 (3-4) ◽  
pp. 119-124
Author(s):  
I. F Gareev ◽  
O. A Beylerli ◽  
A. K Vakhitov
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Heterotopic Ossification ◽  
Genetic Factors ◽  
Cellular Interactions ◽  
Heterotopic Ossifications ◽  
The Brain

Available data on the pathogenesis, cellular interactions, role of inflammation, humoral and genetic factors in the formation of heterotopic ossifications resulting from injuries of the brain or spinal cord are presented.

scholarly journals Emerging Role of Spinal Cord TRPV1 in Pain Exacerbation

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Seung-In Choi ◽  
Ji Yeon Lim ◽  
Sungjae Yoo ◽  
Hyun Kim ◽  
Sun Wook Hwang
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Pain Mechanisms ◽  
Historical Perspectives ◽  
Pain Pathway ◽  
Central Regions ◽  
The Central Nervous System ◽  
Pathological Pain ◽  
Synaptic Mechanisms

TRPV1 is well known as a sensor ion channel that transduces a potentially harmful environment into electrical depolarization of the peripheral terminal of the nociceptive primary afferents. Although TRPV1 is also expressed in central regions of the nervous system, its roles in the area remain unclear. A series of recent reports on the spinal cord synapses have provided evidence that TRPV1 plays an important role in synaptic transmission in the pain pathway. Particularly, in pathologic pain states, TRPV1 in the central terminal of sensory neurons and interneurons is suggested to commonly contribute to pain exacerbation. These observations may lead to insights regarding novel synaptic mechanisms revealing veiled roles of spinal cord TRPV1 and may offer another opportunity to modulate pathological pain by controlling TRPV1. In this review, we introduce historical perspectives of this view and details of the recent promising results. We also focus on extended issues and unsolved problems to fully understand the role of TRPV1 in pathological pain. Together with recent findings, further efforts for fine analysis of TRPV1’s plastic roles in pain synapses at different levels in the central nervous system will promote a better understanding of pathologic pain mechanisms and assist in developing novel analgesic strategies.

scholarly journals The role of connexin43 in neuropathic pain induced by spinal cord injury

2019 ◽  
Vol 51 (6) ◽  
pp. 555-561 ◽  
Author(s):  
Anhui Wang ◽  
Changshui Xu
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Neuropathic Pain ◽  
Cell Metabolism ◽  
Pain Models ◽  
Cord Injury ◽  
The Central Nervous System ◽  
And Function

Abstract Neuropathic pain is caused by the damage or dysfunction of the nervous system. In many neuropathic pain models, there is an increase in the number of gap junction (GJ) channels, especially the upregulation of the expression of connexin43 (Cx43), leading to the secretion of various types of cytokines and involvement in the formation of neuropathic pain. GJs are widely distributed in mammalian organs and tissues, and Cx43 is the most abundant connexin (Cx) in mammals. Astrocytes are the most abundant glial cell type in the central nervous system (CNS), which mainly express Cx43. More importantly, GJs play an important role in regulating cell metabolism, signaling, and function. Many existing literatures showed that Cx43 plays an important role in the nervous system, especially in the CNS under normal and pathological conditions. However, many internal mechanisms have not yet been thoroughly explored. In this review, we summarized the current understanding of the role and association of Cx and pannexin channels in neuropathic pain, especially after spinal cord injury, as well as some of our own insights and thoughts which suggest that Cx43 may become an emerging therapeutic target for future neuropathic pain, bringing new hope to patients.

scholarly journals Notch1 control of oligodendrocyte differentiation in the spinal cord

2002 ◽  
Vol 158 (4) ◽  
pp. 709-718 ◽  
Author(s):  
Stéphane Genoud ◽  
Corinna Lappe-Siefke ◽  
Sandra Goebbels ◽  
Freddy Radtke ◽  
Michel Aguet ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Transgenic Mice ◽  
Oligodendrocyte Differentiation ◽  
Temporal Regulation ◽  
Development And Differentiation ◽  
The Central Nervous System

We have selectively inhibited Notch1 signaling in oligodendrocyte precursors (OPCs) using the Cre/loxP system in transgenic mice to investigate the role of Notch1 in oligodendrocyte (OL) development and differentiation. Early development of OPCs appeared normal in the spinal cord. However, at embryonic day 17.5, premature OL differentiation was observed and ectopic immature OLs were present in the gray matter. At birth, OL apoptosis was strongly increased in Notch1 mutant animals. Premature OL differentiation was also observed in the cerebrum, indicating that Notch1 is required for the correct spatial and temporal regulation of OL differentiation in various regions of the central nervous system. These findings establish a widespread function of Notch1 in the late steps of mammalian OPC development in vivo.

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