scholarly journals A microfluidic-induced C. elegans sleep state

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel L. Gonzales ◽  
Jasmine Zhou ◽  
Bo Fan ◽  
Jacob T. Robinson
Keyword(s):  
Animal Behavior ◽  
Animal Movement ◽  
Quiescent State ◽  
Sleep State ◽  
C Elegans ◽  
Sensory Pathways ◽  
Simultaneous Control ◽  
Behavioral Requirements ◽  
Microfluidic Chambers ◽  
The Brain

Abstract An important feature of animal behavior is the ability to switch rapidly between activity states, however, how the brain regulates these spontaneous transitions based on the animal’s perceived environment is not well understood. Here we show a C. elegans sleep-like state on a scalable platform that enables simultaneous control of multiple environmental factors including temperature, mechanical stress, and food availability. This brief quiescent state, which we refer to as microfluidic-induced sleep, occurs spontaneously in microfluidic chambers, which allows us to track animal movement and perform whole-brain imaging. With these capabilities, we establish that microfluidic-induced sleep meets the behavioral requirements of C. elegans sleep and depends on multiple factors, such as satiety and temperature. Additionally, we show that C. elegans sleep can be induced through mechanosensory pathways. Together, these results establish a model system for studying how animals process multiple sensory pathways to regulate behavioral states.

scholarly journals A quiescent state following mild sensory arousal in Caenorhabditis elegans is potentiated by stress

2019 ◽  
Author(s):  
Patrick D. McClanahan ◽  
Jessica M. Dubuque ◽  
Daphne Kontogiorgos-Heintz ◽  
Ben F. Habermeyer ◽  
Joyce H. Xu ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Light Exposure ◽  
Light Stimulus ◽  
Low Frequency ◽  
Behavioral Responses ◽  
Quiescent State ◽  
Sleep State ◽  
C Elegans ◽  
Epidermal Growth ◽  
Cellular Stressors

AbstractAn animal’s behavioral and physiological response to stressors includes changes to its responses to stimuli. How such changes occur is not well understood. Here we describe a Caenorhabditis elegans quiescent behavior, post-response quiescence (PRQ), which is modulated by the C. elegans response to cellular stressors. Following an aversive mechanical or blue light stimulus, worms respond first by briefly moving, and then become more quiescent for a period lasting tens of seconds. PRQ occurs at low frequency in unstressed animals, but is more frequent in animals that have experienced cellular stress due to ultraviolet light exposure as well as in animals following overexpression of epidermal growth factor (EGF). PRQ requires the function of the carboxypeptidase EGL-21 and the calcium-activated protein for secretion (CAPS) UNC-31, suggesting it has a neuropeptidergic mechanism. Although PRQ requires the sleep-promoting neurons RIS and ALA, it is not accompanied by decreased arousability, and does not appear to be homeostatically regulated, suggesting that it is not a sleep state. PRQ represents a simple, tractable model for studying how neuromodulatory states like stress alter behavioral responses to stimuli.

Insulin signaling and osmotic stress response regulate arousal and developmental progression of C. elegans at hatching

Genetics ◽  
2021 ◽  
Author(s):  
Emily A Bayer ◽  
Katarina M Liberatore ◽  
Jordan R Schneider ◽  
Evan Schlesinger ◽  
Zhengying He ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Insulin Signaling ◽  
Sensory Response ◽  
Quiescent State ◽  
Larval Life ◽  
Sleep State ◽  
Animal Development ◽  
C Elegans ◽  
Developmental Progression ◽  
Osmotic Stress Response

Abstract The progression of animal development from embryonic to juvenile life depends on the coordination of organism-wide responses with environmental conditions. We found that two transcription factors that function in interneuron differentiation in Caenorhabditis elegans, fax-1 and unc-42, are required for arousal and progression from embryogenesis to larval life by potentiating insulin signaling. The combination of mutations in either transcription factor and a mutation in daf-2 insulin receptor results in a novel peri-hatching arrest phenotype; embryos are fully-developed but inactive, often remaining trapped within the eggshell, and fail to initiate pharyngeal pumping. This pathway is opposed by an osmotic sensory response pathway that promotes developmental arrest and a sleep state at the end of embryogenesis in response to elevated salt concentration. The quiescent state induced by loss of insulin signaling or by osmotic stress can be reversed by mutations in genes that are required for sleep. Therefore, countervailing signals regulate late embryonic arousal and developmental progression to larval life, mechanistically linking the two responses. Our findings demonstrate a role for insulin signaling in an arousal circuit, consistent with evidence that insulin-related regulation may function in control of sleep states in many animals. The opposing quiescent arrest state may serve as an adaptive response to the osmotic threat from high salinity environments.

Glia-Neuron Interactions in Caenorhabditis elegans

2019 ◽  
Vol 42 (1) ◽  
pp. 149-168 ◽  
Author(s):  
Aakanksha Singhvi ◽  
Shai Shaham
Keyword(s):  
Caenorhabditis Elegans ◽  
Animal Behavior ◽  
Neuron Development ◽  
Nematode Caenorhabditis Elegans ◽  
C Elegans ◽  
Neuronal Interactions ◽  
Glial Function ◽  
Nervous System Function ◽  
Neuron Interactions ◽  
The Brain

Glia are abundant components of animal nervous systems. Recognized 170 years ago, concerted attempts to understand these cells began only recently. From these investigations glia, once considered passive filler material in the brain, have emerged as active players in neuron development and activity. Glia are essential for nervous system function, and their disruption leads to disease. The nematode Caenorhabditis elegans possesses glial types similar to vertebrate glia, based on molecular, morphological, and functional criteria, and has become a powerful model in which to study glia and their neuronal interactions. Facile genetic and transgenic methods in this animal allow the discovery of genes required for glial functions, and effects of glia at single synapses can be monitored by tracking neuron shape, physiology, or animal behavior. Here, we review recent progress in understanding glia-neuron interactions in C. elegans. We highlight similarities with glia in other animals, and suggest conserved emerging principles of glial function.

scholarly journals Synergistic Effect of Several Neurotransmitters in PFC-NAc-VTA Neural Circuit for the Anti-Depression Effect of Shuganheweitang in a Chronic Unpredictable Mild Stress Model

2021 ◽  
Vol 16 (3) ◽  
pp. 1934578X2110024
Author(s):  
Xin Chen ◽  
Yuanchun Ma ◽  
Xiongjun Mou ◽  
Hao Liu ◽  
Hao Ming ◽  
...  
Keyword(s):  
Animal Behavior ◽  
Neural Circuit ◽  
Concentration Level ◽  
Brain Regions ◽  
Mild Stress ◽  
Depression Effect ◽  
Monoamine Neurotransmitters ◽  
Reward Circuitry ◽  
High Doses ◽  
The Brain

Depression, a major worldwide mental disorder, leads to massive disability and can result in death. The PFC-NAc-VTA neuro circuit is related to emotional, neurovegetative, and cognitive functions, which emerge as a circuit-level framework for understanding reward deficits in depression. Neurotransmitters, which are widely distributed in different brain regions, are important detected targets for the evaluation of depression. Shuganheweitang (SGHWT) is a popular prescription in clinical therapy for depression. In order to investigate its possible pharmacodynamics and anti-depressive mechanism, the complex plant material was separated into different fractions. These in low and high doses, along with low and high doses of SGHWT were tested in animal behavior tests. The low and high doses of SGHWT were more effective than the various fractions, which indicate the importance of synergistic function in traditional Chinese medicine. Furthermore, amino acid (GABA, Glu) and monoamine neurotransmitters (DA, 5-HT, NA, 5-HIAA) in the PFC-NAc-VTA neuro circuit were investigated by UPLC-MS/MS. The level trend of DA and 5-HT were consistent in the PFC-NAc-VTA neuro circuit, whereas 5-HIAA was decreased in the PFC, Glu was decreased in the PFC and VTA, and NA and GABA were decreased in the NAc. The results indicate that the pathogenesis of depression is associated with dysfunction of the PFC-NAc-VTA neural circuit, mainly through the neural projection effects of neurotransmitters associated with various brain regions in the neural circuit. PCA and OPLS-DA score plots demonstrated the similarities of individuals within each group and the differences among the groups. In this study, SGHWT could regulate the concentration level of different neurotransmitters in the PFC-NAc-VTA neuro circuit to improve the depression, which benefitted from the recognition of the brain reward circuitry in mood disorders.

Minds and brains: angels, humans, and brutes

1982 ◽  
Vol 57 (3) ◽  
pp. 309-315
Author(s):  
Mortimer J. Adler
Keyword(s):  
Nervous System ◽  
Animal Behavior ◽  
Personal Experience ◽  
Human Beings ◽  
Content Type ◽  
The Past ◽  
Wide Range ◽  
Conceptual Thought ◽  
The Brain ◽  
Fine Print

✓ In his 1982 Cushing oration, a distinguished philosopher, author, and discerning critic presents a distillate of his phenomenally wide range of personal experience and his familiarity with the great books and teachers of the present and the past. He explores the differences and relationships between human beings, brute animals, and machines. Knowledge of the brain and nervous system contribute to the explanation of all aspects of animal behavior, intelligence, and mentality, but cannot completely explain human conceptual thought.

scholarly journals How Intelligence is Understood Today

2021 ◽  
Vol 16 (3) ◽  
pp. 0
Author(s):  
Rustam Khasanov
Keyword(s):  
Animal Behavior ◽  
Learning Algorithms ◽  
Cognitive Activity ◽  
Reward System ◽  
Assessment System ◽  
New Developments ◽  
Intellectual Abilities ◽  
Complex Adaptive ◽  
The Brain ◽  
Adaptive Abilities

The article is devoted to understanding the ways of explaining intellectual abilities in the light of new developments in the field of artificial intelligence and discoveries related to the study of complex adaptive animal behavior based on the reward system. The paper reviews the latest advances in the development of biologically plausible learning algorithms, the purpose of which is to explain the large amount of accumulated data from the field of neuroscience. Within the framework of this approach, reinforcement learning algorithms are proposed as the basis for any kind of cognitive activity. Understanding intelligence as a set of flexible adaptive abilities to achieve a goal provides a new conceptual framework for explaining how the brain works at a functional level. The formation of forecasts for the future, the construction of time steps and the existence of an internal assessment system in such systems is psychologically and biologically plausible and can potentially become a new milestone in the study of intelligence.

Creativity of the Dream and Sleep State

2019 ◽  
pp. 124-149 ◽  
Author(s):  
Robert Stickgold
Keyword(s):  
Rem Sleep ◽  
Creative Process ◽  
Anterior Cingulate ◽  
Sleep State ◽  
Creative Processes ◽  
Dorsolateral Prefrontal ◽  
Full Speed ◽  
Stored Information ◽  
The Individual ◽  
The Brain

Rapid eye movement (REM) sleep is a stage of sleep that evolved in part to provide a privileged time in each day when the brain is disconnected from sensory input and freed of intentional, directed thought. The neurochemistry and neurophysiology of the brain during REM sleep is optimized for the exploration of normally ignored connections and associations within the brain’s vast repertoire of stored information. This includes changes in the activity of dorsolateral prefrontal, anterior cingulate, and medial orbital frontal cortices and the hippocampus, and reductions in norepinephrine and increases in acetylcholine in the cortex. This exploration of normally weak associations is critical to the creative process, and REM sleep can thus be considered a period of unbridled creativity. Much of this creative process is reflected in the content of dreams. Even without waking dream recall, changes within associative networks produced by the brain mechanisms of dream construction can leave these brain networks—and the individual—primed for reactivation at a later time, leading to the “discovery” of creative insights. Some, but not all, of these brain changes are also seen during periods of quiet rest with activation of the default mode network (DMN). When active, this network can likewise provide a state of enhanced creativity. Nevertheless, REM sleep and dreaming provide a protected two hours every day when creative processes run at full speed.

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