scholarly journals State-Switching Probability Reveals Sleep-Related Biological Drives inDrosophila

2018 ◽  
Author(s):  
Timothy D. Wiggin ◽  
Patricia R. Goodwin ◽  
Nathan C. Donelson ◽  
Chang Liu ◽  
Kien Trinh ◽  
...  

ABSTRACTSleep pressure and sleep depth are key regulators of wake and sleep. Current methods of measuring these parameters inDrosophila melanogasterhave low temporal resolution and/or require disrupting sleep. Here we report a novel analysis tool for high-resolution, non-invasive measurement of sleep pressure and depth from movement data. Probability of transitioning to an active state, P(Wake), measures sleep depth while probability of transitioning to an inactive state, P(Doze), measures sleep pressure.In vivoand computational analyses show that P(Wake) and P(Doze) are independent and control the amount of total sleep. Importantly, we demonstrate that these probabilities are tied to specific biological processes. Genetic and environmental perturbations demonstrate that a given amount of sleep can be produced by many combinations of underlying P(Wake) and P(Doze). We show that measuring sleep pressure and depth continuously, without disturbing on-going behavior, provides greater mechanistic insight into behavior than measuring the amount of sleep alone.

2020 ◽  
Vol 117 (18) ◽  
pp. 10024-10034 ◽  
Author(s):  
Timothy D. Wiggin ◽  
Patricia R. Goodwin ◽  
Nathan C. Donelson ◽  
Chang Liu ◽  
Kien Trinh ◽  
...  

Sleep pressure and sleep depth are key regulators of wake and sleep. Current methods of measuring these parameters in Drosophila melanogaster have low temporal resolution and/or require disrupting sleep. Here we report analysis tools for high-resolution, noninvasive measurement of sleep pressure and depth from movement data. Probability of initiating activity, P(Wake), measures sleep depth while probability of ceasing activity, P(Doze), measures sleep pressure. In vivo and computational analyses show that P(Wake) and P(Doze) are largely independent and control the amount of total sleep. We also develop a Hidden Markov Model that allows visualization of distinct sleep/wake substates. These hidden states have a predictable relationship with P(Doze) and P(Wake), suggesting that the methods capture the same behaviors. Importantly, we demonstrate that both the Doze/Wake probabilities and the sleep/wake substates are tied to specific biological processes. These metrics provide greater mechanistic insight into behavior than measuring the amount of sleep alone.


2007 ◽  
Vol 342-343 ◽  
pp. 901-904
Author(s):  
Yu Bong Kang ◽  
T. Oida ◽  
Duk Young Jung ◽  
A. Fukuma ◽  
T. Azuma ◽  
...  

In order to evaluate the mechanical properties of the human skeletal muscles, the elasticity and viscosity of the human calf muscles were measured with Magnetic Resonance Elastography (MRE). MRE is a novel method to measure the mechanical properties of living soft tissues in vivo quantitatively by observing the strain waves propagated in the object. In this study, the shear modulus and viscosity coefficient were measured with MRE. The shear modulus was 3.7 kPa in relaxed state, and increased with increasing the muscle forces. Interestingly, the viscosity was changed with the vibration frequency applied to the muscles, that was 4.5 Pa·s at 100Hz vibration and 2.4 Pa·s at 200Hz vibration. This shows clearly the visco-elastic property.


2021 ◽  
Vol 6 ◽  
pp. 109
Author(s):  
Tobias C Wood ◽  
Diana Cash ◽  
Eilidh MacNicol ◽  
Camilla Simmons ◽  
Eugene Kim ◽  
...  

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.


1980 ◽  
Vol 59 (3) ◽  
pp. 211-214 ◽  
Author(s):  
I. B. Holbrook ◽  
E. Gross ◽  
P. J. Milewski ◽  
K. Shipley ◽  
M. H. Irving

1. Nτ-Methylhistidine, nitrogen and creatinine were measured in the urine of 10 volunteers on normal and meat-free diets and in 10 vegetarians, and compared with the results from the urine of eight patients with intestinal fistulae on intravenous or enteral nutrition containing no meat. The values obtained were used to calculate fractional breakdown rate of myofibrillar protein. 2. There was a significant fall in the excretion of Nτ-methylhistidine and creatinine and in apparent fractional breakdown rates after 2 days on a meat-free diet. 3. One of the patients had lower, and two of the patients had higher, fractional breakdown rates compared with the vegetarians. 4. Nτ-Methylhistidine and creatinine excretion-5-be a useful and non-invasive measurement of myofibrillar protein degradation in patients on meat-free diets. Firm conclusions cannot, however, be drawn without confirmatory, direct measurement of the breakdown rates of muscle protein in vivo.


2019 ◽  
Vol 54 (S1) ◽  
pp. 18-18
Author(s):  
D. Grevent ◽  
M. Taso ◽  
A. Millischer ◽  
J. Poujol ◽  
H. Mahallati ◽  
...  

2011 ◽  
Author(s):  
Dachao Li ◽  
Wenshuai Liang ◽  
Tongkun Liu ◽  
Haixia Yu ◽  
Kexin Xu

2021 ◽  
Vol 12 ◽  
Author(s):  
Jonathan S. Baillie ◽  
Matthew R. Stoyek ◽  
T. Alexander Quinn

Optogenetics, involving the optical measurement and manipulation of cellular activity with genetically encoded light-sensitive proteins (“reporters” and “actuators”), is a powerful experimental technique for probing (patho-)physiological function. Originally developed as a tool for neuroscience, it has now been utilized in cardiac research for over a decade, providing novel insight into the electrophysiology of the healthy and diseased heart. Among the pioneering cardiac applications of optogenetic actuators were studies in zebrafish, which first demonstrated their use for precise spatiotemporal control of cardiac activity. Zebrafish were also adopted early as an experimental model for the use of optogenetic reporters, including genetically encoded voltage- and calcium-sensitive indicators. Beyond optogenetic studies, zebrafish are becoming an increasingly important tool for cardiac research, as they combine many of the advantages of integrative and reduced experimental models. The zebrafish has striking genetic and functional cardiac similarities to that of mammals, its genome is fully sequenced and can be modified using standard techniques, it has been used to recapitulate a variety of cardiac diseases, and it allows for high-throughput investigations. For optogenetic studies, zebrafish provide additional advantages, as the whole zebrafish heart can be visualized and interrogated in vivo in the transparent, externally developing embryo, and the relatively small adult heart allows for in situ cell-specific observation and control not possible in mammals. With the advent of increasingly sophisticated fluorescence imaging approaches and methods for spatially-resolved light stimulation in the heart, the zebrafish represents an experimental model with unrealized potential for cardiac optogenetic studies. In this review we summarize the use of zebrafish for optogenetic investigations in the heart, highlighting their specific advantages and limitations, and their potential for future cardiac research.


2019 ◽  
Vol 48 (3) ◽  
pp. 464-486
Author(s):  
Radosław Wajman

Nowadays, the application of advanced technologies in modern production systems is the main trend of development and technological progress in many industrial sectors. It is due to the still growing trends of energy-saving and production quality enhancement. Wherever in the production process the phase mixture is transported and it is not optimal or not economic, there is a need to develop a system which would be able to prevent any construction disaster, unexpected production line stopping or situation where for reasons of bad flow parameters, the final product is defective. This paper studies various sensors, measurement techniques and computer methods for signal processing and analysis to diagnose and control two-phase flows. Due to the possibility that the invasive measurement disturbs the process and changes it parameters and behavior especially in the location just after the measurement point and simultaneously does not provide any information about these changes it is unreliable for the diagnosis or control. Therefore, the non-invasive techniques commonly used for measurement of flows parameters are described. Depending on the industrial demands many of applications examples for non-invasive two-phase flows measurement and monitoring are given. This description for identifying the flow parameters is divided into features categories of this phenomena as void fraction distribution, velocity profile and flow regime. However, from these methods the high accuracy and short processing time is expected. The continued observation and monitoring of the process abnormalities can provide valuable information about its dynamic state and allow for real-time and automatic monitoring and control. Therefore, the development of advanced process control is one of the most important challenges to keep the flow regime on the given level and for instant and long-term energy saving, quality improvement.


2021 ◽  
Vol 6 ◽  
pp. 109
Author(s):  
Tobias C Wood ◽  
Diana Cash ◽  
Eilidh MacNicol ◽  
Camilla Simmons ◽  
Eugene Kim ◽  
...  

Malfunctions of oxygen metabolism are suspected to play a key role in a number of neurological and psychiatric disorders, but this hypothesis cannot be properly investigated without an in-vivo non-invasive measurement of brain oxygen consumption. We present a new way to measure the Cerebral Metabolic Rate of Oxygen (CMRO2) by combining two existing magnetic resonance imaging techniques, namely arterial spin-labelling and oxygen extraction fraction mapping. This method was validated by imaging rats under different anaesthetic regimes and was strongly correlated to glucose consumption measured by autoradiography.


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