scholarly journals Putative rapid-acting antidepressant nitrous oxide (“laughing gas”) evokes rebound emergence of slow EEG oscillations during which TrkB signaling is induced

2018 ◽  
Author(s):  
Samuel Kohtala ◽  
Wiebke Theilmann ◽  
Marko Rosenholm ◽  
Paula Kiuru ◽  
Salla Uusitalo ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Cortical Excitability ◽  
Glycogen Synthase ◽  
Neurotrophin Receptor ◽  
Brain State ◽  
Onset Of Action ◽  
Slow Oscillations ◽  
Laughing Gas ◽  
Antidepressant Effects ◽  
Underlying Mechanisms

AbstractElectroconvulsive therapy (ECT) remains among the most efficient antidepressants but it seldom brings immediate remedy. However, a subanesthetic dose of NMDA-R (N-methyl-D-aspartate receptor) blocker ketamine ameliorates symptoms of depression already within hours. Glutamatergic excitability and regulation of TrkB neurotrophin receptor and GSK3β (glycogen synthase kinase 3β) signaling are considered as molecular-level determinants for ketamine’s antidepressant effects. Recent clinical observations suggests that nitrous oxide (N2O, “laughing gas”), another NMDA-R blocking dissociative anesthestic, also produces rapid antidepressant effects but the underlying mechanisms remain essentially unstudied. In this animal study we show that N2O, with a clinically relevant dosing regimen, evokes an emergence of rebound slow EEG (electroencephalogram) oscillations, a phenomenon considered to predict the efficacy and onset-of-action ECT. Very similar rebound slow oscillations are induced by subanesthetic ketamine and flurothyl (a treatment analogous to ECT). These responses become best evident upon drug withdrawal, i.e. after the peak of acute pharmacological actions, when their most prominent effects on cortical excitability have subsided. Most importantly, TrkB and GSK3β signaling remain unchanged during N2O administration (ongoing NMDA-R blockade) but emerge gradually upon gas withdrawal along with increased slow EEG oscillations. Collectively these findings reveal that rapid-acting antidepressants produce cortical excitability that triggers “a brain state” dominated by ongoing slow oscillations, sedation and drowsiness during which TrkB and GSK3β signaling alterations are induced.

Nitrous oxide as a diazo transfer reagent: the synthesis of triazolopyridines

2021 ◽  
Author(s):  
Iris R. Landman ◽  
Farzaneh Fadaei-Tirani ◽  
Kay Severin
Keyword(s):  
Nitrous Oxide ◽  
Laughing Gas

Nitrous oxide (N2O, ‘laughing gas’) can be used as diazo transfer reagent for the synthesis of triazolopyridines.

scholarly journals Chronic pain relief after the exposure of nitrous oxide during dental treatment: longitudinal retrospective study

2015 ◽  
Vol 73 (7) ◽  
pp. 578-581 ◽  
Author(s):  
Francisco Moreira Mattos Júnior ◽  
Rafael Villanova Mattos ◽  
Manoel Jacobsen Teixeira ◽  
Silvia Regina Dowgan Tesseroli de Siqueira ◽  
Jose Tadeu Tesseroli de Siqueira
Keyword(s):  
Chronic Pain ◽  
Nitrous Oxide ◽  
Dental Treatment ◽  
Chronic Pain Patients ◽  
Before And After ◽  
Nitrous Oxide Oxygen ◽  
Oxygen Nitrous Oxide ◽  
Prevalence Of Pain ◽  
Underlying Mechanisms ◽  
Pain Patients

The objective was to investigate the effect of nitrous/oxygen in chronic pain. Seventy-seven chronic pain patients referred to dental treatment with conscious sedation with nitrous oxide/oxygen had their records included in this research. Data were collected regarding the location and intensity of pain by the visual analogue scale before and after the treatment. Statistical analysis was performed comparing pre- and post-treatment findings. It was observed a remarkable decrease in the prevalence of pain in this sample (only 18 patients still had chronic pain, p < 0.001) and in its intensity (p < 0.001). Patients that needed fewer sessions received higher proportions of nitrous oxide/oxygen. Nitrous oxide may be a tool to be used in the treatment of chronic pain, and future prospective studies are necessary to understand the underlying mechanisms and the effect of nitrous oxide/oxygen in patients according to the pain diagnosis and other characteristics.

scholarly journals Asparagus cochinchinensis extract ameliorates menopausal depression in ovariectomized rats under chronic unpredictable mild stress

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hye Ryeong Kim ◽  
Young-Ju Lee ◽  
Tae-Wan Kim ◽  
Ri-Na Lim ◽  
Dae Youn Hwang ◽  
...  
Keyword(s):  
Tricyclic Antidepressant ◽  
Ovariectomized Rats ◽  
Mild Stress ◽  
Chronic Unpredictable Mild Stress ◽  
Ovx Rats ◽  
Antidepressant Effects ◽  
Antidepressant Imipramine ◽  
Asparagus Cochinchinensis ◽  
Underlying Mechanisms ◽  
Menopausal Depression

Abstract Background Depression is a serious and common psychiatric disorder generally affecting more women than men. A woman’s risk of developing depression increases steadily with age, and higher incidence is associated with the onset of menopause. Here we evaluated the antidepressant properties of Asparagus cochinchinensis (AC) extract and investigated its underlying mechanisms in a rat menopausal depression model. Methods To model this menopausal depression, we induced a menopause-like state in rats via ovariectomy and exposed them to chronic unpredictable mild stress (CUMS) for 6 weeks, which promotes the development of depression-like symptoms. During the final 4 weeks of CUMS, rats were treated with either AC extract (1000 or 2000 mg/kg, PO), which has been reported to provide antidepressant effects, or with the tricyclic antidepressant imipramine (10 mg/kg, IP). Results We report that CUMS promotes depression-like behavior and significantly increases serum corticosterone and inflammatory cytokine levels in the serum of ovariectomized (OVX) rats. We also found that CUMS decreases the expression of brain-derived neurotrophic factor (BDNF) and its primary receptor, tropomyosin receptor kinase B (TrkB), in OVX rats, and treatment with AC extract rescues both BDNF and TrkB expression levels. Conclusion These results suggest that AC extract exerts antidepressant effects, possibly via modulation of the BDNF-TrkB pathway, in a rat model of menopausal depression.

scholarly journals Neural activity related to volitional regulation of cortical excitability

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Kathy Ruddy ◽  
Joshua Balsters ◽  
Dante Mantini ◽  
Quanying Liu ◽  
Pegah Kassraian-Fard ◽  
...  
Keyword(s):  
Magnetic Stimulation ◽  
Dynamic Range ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Recovery Of Function ◽  
Brain State ◽  
Large Dynamic Range ◽  
Conditioning Paradigm ◽  
Alpha Oscillations ◽  
Human Motor

To date there exists no reliable method to non-invasively upregulate or downregulate the state of the resting human motor system over a large dynamic range. Here we show that an operant conditioning paradigm which provides neurofeedback of the size of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS), enables participants to self-modulate their own brain state. Following training, participants were able to robustly increase (by 83.8%) and decrease (by 30.6%) their MEP amplitudes. This volitional up-versus down-regulation of corticomotor excitability caused an increase of late-cortical disinhibition (LCD), a TMS derived read-out of presynaptic GABAB disinhibition, which was accompanied by an increase of gamma and a decrease of alpha oscillations in the trained hemisphere. This approach paves the way for future investigations into how altered brain state influences motor neurophysiology and recovery of function in a neurorehabilitation context.

scholarly journals Synthetic chemistry with nitrous oxide

2015 ◽  
Vol 44 (17) ◽  
pp. 6375-6386 ◽  
Author(s):  
Kay Severin
Keyword(s):  
Inorganic Chemistry ◽  
Nitrous Oxide ◽  
Synthetic Chemistry ◽  
Laughing Gas ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Nitrous oxide (N2O, ‘laughing gas’) is a very inert molecule. Still, it can be used as a reagent in synthetic organic and inorganic chemistry, serving as O-atom donor, as N-atom donor, or as a oxidant in metal-catalyzed reactions.

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