High-throughput screening in larval zebrafish identifies novel potent sedative-hypnotics

BACKGROUND: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds. METHODS: The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent. RESULTS: Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors. CONCLUSIONS: Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.This work was supported by grants from Shanghai Jiaotong University School of Medicine, Shanghai, China, and the Chinese Medical Association, Beijing, China (both to Dr. Yang). The Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts, supported this work through a Research Scholars Award and an Innovation Grant (both to Dr. Forman). Contributions to this research from the Boston University Center for Molecular Discovery, Boston, Massachusetts (to Drs. Porco, Brown, Schaus, and Xu, and to Mr. Trilles), were supported by a grant from the National Institutes of Health, Bethesda, Maryland (grant No. R24 GM111625). (Shanghai Jiaotong University School of Medicine, Shanghai, China; Chinese Medical Association, Beijing, China; Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts; R24 GM111625 - National Institutes of Health, Bethesda, Maryland)Accepted manuscript2019-09-0

Desynchronization of pathological low-frequency brain activity by the hypnotic drug zolpidem.

Reports of the beneficial effects of the hypnotic imidazopyridine, zolpidem, described in persistent vegetative state^1, 2^ have been replicated recently in brain-injured and cognitively impaired patients^3-7^. Previous single photon emission computed tomography (SPECT) studies have suggested that sub-sedative doses of zolpidem increased regional cerebral perfusion in affected areas^5, 8^, implying enhanced neuronal metabolic activity; which has led to speculation that zolpidem 'reawakens' functionally dormant cortex. However, a neuronal mechanism by which this hypnotic drug affords benefits to brain injured patients has yet to be demonstrated. Here, we report the action of sub-sedative doses of zolpidem on neuronal network oscillatory activity in human brain, measured using pharmaco-magnetoencephalography (pharmaco-MEG). Study participant JP suffered a stroke in 1996, causing major damage to the left hemisphere that impaired aspects of both motor and cognitive function. Pharmaco-MEG analyses revealed robust and persistent pathological theta (4-10Hz) and beta (15-30Hz) oscillations within the lesion penumbra and surrounding cortex. Administration of zolpidem (5mg) reduced the power of pathological theta and beta oscillations in all regions of the lesioned hemisphere. This desynchronizing effect correlated well with zolpidem uptake (occurring approximately 40 minutes after acute administration) and was coincident with marked improvements in cognitive and motor function. Control experiments revealed no effect of placebo, while a structurally unrelated hypnotic, zopiclone, administered at a comparable dose (3.5mg) elicited widespread increases in cortical oscillatory power in the beta (15-30Hz) band without functional improvement. These results suggest that in JP, specific motor and cognitive impairments are related to increased low-frequency oscillatory neuronal network activity. Zolpidem is unique amongst hypnotic drugs in its ability to desynchronize such pathological low-frequency activity, thereby restoring cognitive function

Manual control analysis of drug effects on driving performance

The effects of secobarbital, diazepam, alcohol, and marihuana on car-driver transfer functions obtained using a driving simulator were studied. The first three substances, all CNS depressants, reduced gain, crossover frequency, and coherence which resulted in poorer tracking performance. Marihuana also impaired tracking performance but the only effect on the transfer function parameters was to reduce coherence

The Association between Sleep Problems, Sleep Medication Use, and Falls in Community-Dwelling Older Adults: Results from the Health and Retirement Study 2010

Background. Very few studies have assessed the impact of poor sleep and sleep medication use on the risk of falls among community-dwelling older adults. The objective of this study was to evaluate the association between sleep problems, sleep medication use, and falls in community-dwelling older adults. Methods. The study population comprised a nationally representative sample of noninstitutionalized older adults participating in the 2010 Health and Retirement Study. Proportion of adults reporting sleep problems, sleep medication use, and fall was calculated. Multiple logistic regression models were constructed to examine the impact of sleep problems and sleep medication use on the risk of falls after controlling for covariates. Results. Among 9,843 community-dwelling older adults, 35.8% had reported a fall and 40.8% had reported sleep problems in the past two years. Sleep medication use was reported by 20.9% of the participants. Older adults who do have sleep problems and take sleep medications had a significant high risk of falls, compared to older adults who do not have sleep problems and do not take sleep medications. The other two groups also had significantly greater risk for falls. Conclusion. Sleep problems added to sleep medication use increase the risk of falls. Further prospective studies are needed to confirm these observed findings

Uji Efek Hipnotik-Sedatif Ekstrak Etanol 70 % Batang Jaka Tuwa (Scoparia Dulcis Linn) Terhadap Mencit Jantan Galur Swiss Webster

THE HYPNOTIC EFFECT OF 70% ETHANOLIC EXTRACTS OF Scoparia dulcis Linn STEM ON SWISS WEBSTER MALEMICE Dyah Ayu Purwita Sari , Safari Wahyu Jatmiko Medical Faculty, Muhammadiyah SurakartaUniversity Background :Scoparia dulcis Linn contains flavonoids, tannins and saponins which have sedatif hypnotic effect. Objective: This study aims to determine the effect of 70% ethanolic extract of Scoparia dulcis Linn stem in giving hypnotic-sedatif effects on Swiss Webster male mice. Methods : This study is a laboratory experimental research with post test only control group design. The control group was used for comparison and evaluation. The objects of the study were 30 Swiss Webster male mice, weight 20-30 grams, 2-3 months old, divided into 5 groups with simple random sampling technique. Negatif control group (aquadest), positive control group (diazepam 1 mg/kgBW mice), treatment group dose I (50 mg/kgBW), dose II (100 mg/kgBW) and dose III (200 mg/kgBW). The sleep onset was calculated from the time treatment was given until the loss of righting reflex. The research was analyzed using post test only and one way ANOVA followed by Post Hoc Test. Results :The ethanol extract of 70% stem Jaka Tuwa dose III (200mg / kgWB) had sedative hypnotic effect that accelerated the onset of mice sleep with mean of 29.3 min (p 0.005 so it is not statistically significant. In one way ANOVA statistic test showed p value = 0.000 (p <0,05), so there was significant difference of onset of sleep of mice between group Conclusion :70% ethanol extract of Jaka Tuwa (Scoparia dulcis Linn) stem dose of 200mg / kgWB has a better sedative hypnotic effect than diazepam in Swiss Webster strain mice. ________________________________________ Keywords : Extracts of Scoparia dulcis Linn Stem, Sleep Disturbance,Hypnotic-Sedatif Effect

Sedative and hypnotic effects of Iranian traditional medicinal herbs used for treatment of insomnia

For tens of centuries, plants have been highly valued and regularly used as medicine amongst the masses. Insomnia, a loss of sleep, is mostly treated by synthetic sleeping tablets these days. However, questions have been raised about the safety of prolonged use of artificial sedatives due to their deleterious side effects such as physical dependence. In recent years, there has been an increasing propensity to preclude insomnia by herbal medicines throughout the world. Many herbs have a lengthy background in terms of insomnia treatment in Iran. This paper gives an account of previously published research on sedative and hypnotic effects of medicinal herbs used for treatment of insomnia in Iranian traditional medicine

Differential Actions of Ethanol and Trichloroethanol at Sites in the M3 and M4 Domains of the NMDA Receptor GluN2A (NR2A) Subunit

Background and purpose:  Alcohol produces its behavioural effects in part due to inhibition of N-methyl-d-aspartate (NMDA) receptors in the CNS. Previous studies have identified amino acid residues in membrane-associated domains 3 (M3) and 4 (M4) of the NMDA receptor that influence ethanol sensitivity. In addition, in other alcohol-sensitive ion channels, sedative-hypnotic agents have in some cases been shown to act at sites distinct from the sites of ethanol action. In this study, we compared the influence of mutations at these sites on sensitivity to ethanol and trichloroethanol, a sedative-hypnotic agent that is a structural analogue of ethanol. Experimental approach:  We constructed panels of mutants at ethanol-sensitive positions in the GluN2A (NR2A) NMDA receptor subunit and transiently expressed these mutants in human embryonic kidney 293 cells. We used whole-cell patch-clamp recording to assess the actions of ethanol and trichloroethanol in these mutant NMDA receptors. Key results:  Ethanol sensitivity of mutants at GluN2A(Ala825) was not correlated with any physicochemical measures tested. Trichloroethanol sensitivity was altered in two of three ethanol-insensitive mutant GluN2A subunits: GluN2A(Phe637Trp) in M3 and GluN2A(Ala825Trp) in M4, but not GluN2A(Met823Trp). Trichloroethanol sensitivity decreased with increasing molecular volume at Phe637 or increasing hydrophobicity at Ala825 and was correlated with ethanol sensitivity at both sites. Conclusions and implications:  Evidence obtained to date is consistent with a role of GluN2A(Ala825) as a modulatory site for ethanol and trichloroethanol sensitivity, but not as a binding site. Trichloroethanol appears to inhibit the NMDA receptor in a manner similar, but not identical to, that of ethanol