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Pandi-Perumal SR, Saravanan KM, Paul S, Chidambaram SB. Harnessing Simple Animal Models to Decode Sleep Mysteries. Mol Biotechnol 2024:10.1007/s12033-024-01318-z. [PMID: 39579174 DOI: 10.1007/s12033-024-01318-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Accepted: 10/28/2024] [Indexed: 11/25/2024]
Abstract
Whether it involves human subjects or non-human animals, basic, translational, or clinical sleep research poses significant ethical challenges for researchers and ethical committees alike. Sleep research greatly benefits from using diverse animal models, each offering unique insights into sleep control mechanisms. The fruit fly (Drosophila melanogaster) is a superior genetic model due to its quick generation period, large progenies, and rich genetic tools. Its well-characterized genome and ability to respond to hypnotics and stimulants make it an effective tool for studying sleep genetics and physiological foundations. The nematode (Caenorhabditis elegans) has a simpler neural organization and transparent body, allowing researchers to explore molecular underpinnings of sleep control. Vertebrate models, like zebrafish (Danio rerio), provide insights into circadian rhythm regulation, memory consolidation, and drug effects on sleep. Invertebrate models, like California sea hare (Aplysia californica) and Upside-down jellyfish (Cassiopea xamachana), have simpler nervous systems and behave similarly to humans, allowing for the examination of sleep principles without logistical and ethical challenges. Combining vertebrate and invertebrate animal models offers a comprehensive approach to studying sleep, improving our understanding of sleep regulation and potentially leading to new drug discovery processes for sleep disorders and related illnesses.
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Affiliation(s)
- Seithikurippu R Pandi-Perumal
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, 570015, Karnataka, India
- Centre for Research and Development, Chandigarh University, Mohali, 140413, Punjab, India
- Division of Research and Development, Lovely Professional University, Phagwara, 144411, Punjab, India
| | | | - Sayan Paul
- Department of Biochemistry & Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77555, USA
| | - Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, Mysuru, 570015, Karnataka, India.
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, Mysuru, 570015, Karnataka, India.
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2
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Bauhus MB, Mews S, Kurtz J, Brinker A, Peuß R, Anaya-Rojas JM. Tapeworm infection affects sleep-like behavior in three-spined sticklebacks. Sci Rep 2024; 14:23395. [PMID: 39379533 PMCID: PMC11461891 DOI: 10.1038/s41598-024-73992-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 09/23/2024] [Indexed: 10/10/2024] Open
Abstract
Sleep is a complex and conserved biological process that affects several body functions and behaviors. Evidence suggests that there is a reciprocal interaction between sleep and immunity. For instance, fragmented sleep can increase the probability of parasitic infections and reduce the ability to fight infections. Moreover, viral and bacterial infections alter the sleep patterns of infected individuals. However, the effects of macro-parasitic infections on sleep remain largely unknown, and measuring sleep in non-model organisms remains challenging. In this study, we investigated whether macro-parasite infections could alter sleep-like behavior of their hosts. We experimentally infected three-spined sticklebacks (Gasterosteus aculeatus), a freshwater fish, with the tapeworm Schistocephalus solidus and used a hidden Markov model to characterize sleep-like behavior in sticklebacks. One to four days after parasite exposure, infected fish showed no difference in sleep-like behavior compared with non-exposed fish, and fish that were exposed-but-not-infected only showed a slight reduction in sleep-like behavior during daytime. Twenty-nine to 32 days after exposure, infected fish showed more sleep-like behavior than control fish, while exposed-but-not-infected fish showed overall less sleep-like behavior. Using brain transcriptomics, we identified immune- and sleep-associated genes that potentially underlie the observed behavioral changes. These results provide insights into the complex association between macro-parasite infection, immunity, and sleep in fish and may thus contribute to a better understanding of reciprocal interactions between sleep and immunity.
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Affiliation(s)
- Marc B Bauhus
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstraße 1, 48149, Münster, Germany
| | - Sina Mews
- Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33614, Bielefeld, Germany
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstraße 1, 48149, Münster, Germany
- Joint Institute for Individualisation in a Changing Environment, University of Münster and Bielefeld University, Münster, Bielefeld, Germany
| | - Alexander Brinker
- Fisheries Research Station Baden-Württemberg, Argenweg 50/1, 88085, Langenargen, Germany
- Institute for Limnology, University of Constance, Mainaustraße 252, 78464, Constance, Germany
| | - Robert Peuß
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstraße 1, 48149, Münster, Germany.
- Joint Institute for Individualisation in a Changing Environment, University of Münster and Bielefeld University, Münster, Bielefeld, Germany.
| | - Jaime M Anaya-Rojas
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstraße 1, 48149, Münster, Germany
- Joint Institute for Individualisation in a Changing Environment, University of Münster and Bielefeld University, Münster, Bielefeld, Germany
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3
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Beetz MJ. A perspective on neuroethology: what the past teaches us about the future of neuroethology. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2024; 210:325-346. [PMID: 38411712 PMCID: PMC10995053 DOI: 10.1007/s00359-024-01695-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/28/2024]
Abstract
For 100 years, the Journal of Comparative Physiology-A has significantly supported research in the field of neuroethology. The celebration of the journal's centennial is a great time point to appreciate the recent progress in neuroethology and to discuss possible avenues of the field. Animal behavior is the main source of inspiration for neuroethologists. This is illustrated by the huge diversity of investigated behaviors and species. To explain behavior at a mechanistic level, neuroethologists combine neuroscientific approaches with sophisticated behavioral analysis. The rapid technological progress in neuroscience makes neuroethology a highly dynamic and exciting field of research. To summarize the recent scientific progress in neuroethology, I went through all abstracts of the last six International Congresses for Neuroethology (ICNs 2010-2022) and categorized them based on the sensory modalities, experimental model species, and research topics. This highlights the diversity of neuroethology and gives us a perspective on the field's scientific future. At the end, I highlight three research topics that may, among others, influence the future of neuroethology. I hope that sharing my roots may inspire other scientists to follow neuroethological approaches.
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Affiliation(s)
- M Jerome Beetz
- Zoology II, Biocenter, University of Würzburg, 97074, Würzburg, Germany.
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4
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Thiede KI, Born J, Vorster APA. Sleep and conditioning of the siphon withdrawal reflex in Aplysia. J Exp Biol 2021; 224:271187. [PMID: 34346500 DOI: 10.1242/jeb.242431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 07/30/2021] [Indexed: 11/20/2022]
Abstract
Sleep is essential for memory consolidation after learning as shown in mammals and invertebrates such as bees and flies. Aplysia californica displays sleep, and sleep in this mollusk was also found to support memory for an operant conditioning task. Here, we investigated whether sleep in Aplysia is also required for memory consolidation in a simpler type of learning, i.e. the conditioning of the siphon withdrawal reflex. Two groups of animals (Wake, Sleep, each n=11) were conditioned on the siphon withdrawal reflex, with the training following a classical conditioning procedure where an electrical tail shock served as the unconditioned stimulus (US) and a tactile stimulus to the siphon as the conditioned stimulus (CS). Responses to the CS were tested before (pre-test), and 24 and 48 h after training. While Wake animals remained awake for 6 h after training, Sleep animals had undisturbed sleep. The 24 h test in both groups was combined with extinction training, i.e. the extended presentation of the CS alone over two blocks. At the 24 h test, siphon withdrawal duration in response to the CS was distinctly enhanced in both Sleep and Wake groups with no significant difference between groups, consistent with the view that consolidation of a simple conditioned reflex response does not require post-training sleep. Surprisingly, extinction training did not reverse the enhancement of responses to the CS. On the contrary, at the 48 h test, withdrawal duration in response to the CS was even further enhanced across both groups. This suggests that processes of sensitization, an even simpler non-associative type of learning, contributed to the withdrawal responses. Our study provides evidence for the hypothesis that sleep preferentially benefits consolidation of more complex learning paradigms than conditioning of simple reflexes.
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Affiliation(s)
- Kathrin I Thiede
- Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience CIN, University of Tübingen, Tübingen 72076, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience CIN, University of Tübingen, Tübingen 72076, Germany.,German Center for Diabetes Research (DZD), Institute for Diabetes Research & Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen (IDM), Tübingen 72076, Germany
| | - Albrecht P A Vorster
- Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience CIN, University of Tübingen, Tübingen 72076, Germany.,Training Centre of Neuroscience (GTC)/International Max Planck Research School (IMPRS) at the University of Tübingen, Tübingen 72076, Germany
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5
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Melnattur K, Morgan E, Duong V, Kalra A, Shaw PJ. The Sleep Nullifying Apparatus: A Highly Efficient Method of Sleep Depriving Drosophila. J Vis Exp 2020. [PMID: 33369606 DOI: 10.3791/62105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Sleep homeostasis, the increase in sleep observed following sleep loss, is one of the defining criteria used to identify sleep throughout the animal kingdom. As a consequence, sleep deprivation and sleep restriction are powerful tools that are commonly used to provide insight into sleep function. Nonetheless, sleep deprivation experiments are inherently problematic in that the deprivation stimulus itself may be the cause of observed changes in physiology and behavior. Accordingly, successful sleep deprivation techniques should keep animals awake and, ideally, result in a robust sleep rebound without also inducing a large number of unintended consequences. Here, we describe a sleep deprivation technique for Drosophila melanogaster. The Sleep Nullifying Apparatus (SNAP) administers a stimulus every 10s to induce negative geotaxis. Although the stimulus is predictable, the SNAP effectively prevents >95% of nighttime sleep even in flies with high sleep drive. Importantly, the subsequent homeostatic response is very similar to that achieved using hand-deprivation. The timing and spacing of the stimuli can be modified to minimize sleep loss and thus examine non-specific effects of the stimulus on physiology and behavior. The SNAP can also be used for sleep restriction and to assess arousal thresholds. The SNAP is a powerful sleep disruption technique that can be used to better understand sleep function.
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Affiliation(s)
- Krishna Melnattur
- Department of Neuroscience, Washington University School of Medicine
| | - Ellen Morgan
- Department of Neuroscience, Washington University School of Medicine
| | - Vincent Duong
- Department of Neuroscience, Washington University School of Medicine
| | - Arjan Kalra
- Department of Neuroscience, Washington University School of Medicine
| | - Paul J Shaw
- Department of Neuroscience, Washington University School of Medicine;
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Abstract
General anesthesia serves a critically important function in the clinical care of human patients. However, the anesthetized state has foundational implications for biology because anesthetic drugs are effective in organisms ranging from paramecia, to plants, to primates. Although unconsciousness is typically considered the cardinal feature of general anesthesia, this endpoint is only strictly applicable to a select subset of organisms that are susceptible to being anesthetized. We review the behavioral endpoints of general anesthetics across species and propose the isolation of an organism from its environment - both in terms of the afferent arm of sensation and the efferent arm of action - as a generalizable definition. We also consider the various targets and putative mechanisms of general anesthetics across biology and identify key substrates that are conserved, including cytoskeletal elements, ion channels, mitochondria, and functionally coupled electrical or neural activity. We conclude with a unifying framework related to network function and suggest that general anesthetics - from single cells to complex brains - create inefficiency and enhance modularity, leading to the dissociation of functions both within an organism and between the organism and its surroundings. Collectively, we demonstrate that general anesthesia is not restricted to the domain of modern medicine but has broad biological relevance with wide-ranging implications for a diverse array of species.
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Affiliation(s)
- Max B Kelz
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Perelman School of Medicine, 3620 Hamilton Walk, 334 John Morgan Building, Philadelphia, PA 19104, USA; Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Translational Research Laboratories, 125 S. 31st St., Philadelphia, PA 19104-3403, USA; Mahoney Institute for Neuroscience, University of Pennsylvania, Clinical Research Building, 415 Curie Blvd, Philadelphia, PA 19104, USA.
| | - George A Mashour
- Department of Anesthesiology, University of Michigan, 7433 Medical Science Building 1, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA; Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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Abstract
For many decades, sleep researchers have sought to determine which species 'have' rapid eye movement (REM) sleep. In doing so, they relied predominantly on a template derived from the expression of REM sleep in the adults of a small number of mammalian species. Here, we argue for a different approach that focuses less on a binary decision about haves and have nots, and more on the diverse expression of REM sleep components over development and across species. By focusing on the components of REM sleep and discouraging continued reliance on a restricted template, we aim to promote a richer and more biologically grounded developmental-comparative approach that spans behavioral, physiological, neural, and ecological domains.
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Affiliation(s)
- Mark S Blumberg
- Department of Psychological and Brain Sciences, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA.
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
| | - Paul-Antoine Libourel
- Neurosciences Research Center of Lyon, CNRS UMR5292, INSERM U1028, University Claude Bernard Lyon 1 Neurocampus, 95 Boulevard Pinel, 69675 BRON, France
| | - Markus H Schmidt
- Department of Neurology, Bern University Hospital (Inselspital), University of Bern, Freiburgstrasse 18, 3010 Bern, Switzerland; Ohio Sleep Medicine Institute, 4975 Bradenton Avenue, Dublin, OH 43017, USA
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany.
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Hill VM, O’Connor RM, Shirasu-Hiza M. Tired and stressed: Examining the need for sleep. Eur J Neurosci 2020; 51:494-508. [PMID: 30295966 PMCID: PMC6453762 DOI: 10.1111/ejn.14197] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 09/04/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022]
Abstract
A key feature of circadian rhythms is the sleep/wake cycle. Sleep causes reduced responsiveness to the environment, which puts animals in a particularly vulnerable state; yet sleep has been conserved throughout evolution, indicating that it fulfils a vital purpose. A core function of sleep across species has not been identified, but substantial advances in sleep research have been made in recent years using the genetically tractable model organism, Drosophila melanogaster. This review describes the universality of sleep, the regulation of sleep, and current theories on the function of sleep, highlighting a historical and often overlooked theory called the Free Radical Flux Theory of Sleep. Additionally, we summarize our recent work with short-sleeping Drosophila mutants and other genetic and pharmacological tools for manipulating sleep which supports an antioxidant theory of sleep and demonstrates a bi-directional relationship between sleep and oxidative stress.
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Affiliation(s)
- Vanessa M. Hill
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
| | - Reed M. O’Connor
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
| | - Mimi Shirasu-Hiza
- Department of Genetics and Development; Columbia University Medical Center; NY, NY, 10032; USA
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9
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Andersen ML. A brief report on early sleep studies. Sleep Sci 2020; 13:1-2. [PMID: 32670485 PMCID: PMC7347364 DOI: 10.5935/1984-0063.20190144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Monica Levy Andersen
- Departamento de Psicobiologia, Universidade Federal de São Paulo Rua Napoleão de Barros, 925, 04024- 002, São Paulo SP, Brazil,Corresponding author: Monica Levy Andersen. E-mail:
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10
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Xu G, Yang T, Shen H. Effect of Circadian Clock and Light-Dark Cycles in Onchidium reevesii: Possible Implications for Long-Term Memory. Genes (Basel) 2019; 10:E488. [PMID: 31252693 PMCID: PMC6679201 DOI: 10.3390/genes10070488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 06/13/2019] [Accepted: 06/24/2019] [Indexed: 11/28/2022] Open
Abstract
The sea slug Onchidium reevesii inhabits the intertidal zone, which is characterized by a changeable environment. Although the circadian modulation of long-term memory (LTM) is well documented, the interaction of the circadian clock with light-dark masking in LTM of intertidal animals is not well understood. We characterized the LTM of Onchidium and tested the expression levels of related genes under a light-dark (LD) cycle and constant darkness (i.e., dark-dark, or DD) cycle. Results indicated that both learning behavior and LTM show differences between circadian time (CT) 10 and zeitgeber time (ZT) 10. In LD, the cry1 gene expressed irregularly, and per2 expression displayed a daily pattern and a peak expression level at ZT 18. OnCREB1 (only in LD conditions) and per2 transcripts cycled in phase with each other. In DD, the cry1 gene had its peak expression at CT 10, and per2 expressed its peak level at CT 18. OnCREB1 had two peak expression levels at ZT 10 or ZT 18 which correspond to the time node of peaks in cry1 and per2, respectively. The obtained results provide an LTM pattern that is different from other model species of the intertidal zone. We conclude that the daily transcriptional oscillations of Onchidium for LTM were affected by circadian rhythms and LD cycle masking.
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Affiliation(s)
- Guolyu Xu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
- International Research Center for Marine Biosciences, Shanghai Ocean University, Ministry of Science and Technology, Shanghai 201306, China.
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China.
| | - Tiezhu Yang
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
- International Research Center for Marine Biosciences, Shanghai Ocean University, Ministry of Science and Technology, Shanghai 201306, China.
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China.
| | - Heding Shen
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
- International Research Center for Marine Biosciences, Shanghai Ocean University, Ministry of Science and Technology, Shanghai 201306, China.
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China.
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Toda H, Shi M, Williams JA, Sehgal A. Genetic Mechanisms Underlying Sleep. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2019; 83:57-61. [PMID: 30936393 DOI: 10.1101/sqb.2018.83.037705] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sleep is important for cognitive ability, and perturbations of sleep are associated with a myriad of brain disorders. However, how sleep promotes health and function during wake is poorly understood. To address the cellular and molecular mechanisms underlying sleep, we use the fruit fly Drosophila melanogaster as a genetic model. Forward genetic approaches in flies were critical for deciphering molecular mechanisms of the circadian clock. Using similar approaches, we and others are gaining insights into the pathways that control sleep amount.
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Affiliation(s)
- Hirofumi Toda
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mi Shi
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Julie A Williams
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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12
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Miladinović Đ, Muheim C, Bauer S, Spinnler A, Noain D, Bandarabadi M, Gallusser B, Krummenacher G, Baumann C, Adamantidis A, Brown SA, Buhmann JM. SPINDLE: End-to-end learning from EEG/EMG to extrapolate animal sleep scoring across experimental settings, labs and species. PLoS Comput Biol 2019; 15:e1006968. [PMID: 30998681 PMCID: PMC6490936 DOI: 10.1371/journal.pcbi.1006968] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 04/30/2019] [Accepted: 03/20/2019] [Indexed: 11/18/2022] Open
Abstract
Understanding sleep and its perturbation by environment, mutation, or medication remains a central problem in biomedical research. Its examination in animal models rests on brain state analysis via classification of electroencephalographic (EEG) signatures. Traditionally, these states are classified by trained human experts by visual inspection of raw EEG recordings, which is a laborious task prone to inter-individual variability. Recently, machine learning approaches have been developed to automate this process, but their generalization capabilities are often insufficient, especially across animals from different experimental studies. To address this challenge, we crafted a convolutional neural network-based architecture to produce domain invariant predictions, and furthermore integrated a hidden Markov model to constrain state dynamics based upon known sleep physiology. Our method, which we named SPINDLE (Sleep Phase Identification with Neural networks for Domain-invariant LEearning) was validated using data of four animal cohorts from three independent sleep labs, and achieved average agreement rates of 99%, 98%, 93%, and 97% with scorings from five human experts from different labs, essentially duplicating human capability. It generalized across different genetic mutants, surgery procedures, recording setups and even different species, far exceeding state-of-the-art solutions that we tested in parallel on this task. Moreover, we show that these scored data can be processed for downstream analyzes identical to those from human-scored data, in particular by demonstrating the ability to detect mutation-induced sleep alteration. We provide to the scientific community free usage of SPINDLE and benchmarking datasets as an online server at https://sleeplearning.ethz.ch. Our aim is to catalyze high-throughput and well-standardized experimental studies in order to improve our understanding of sleep.
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Affiliation(s)
- Đorđe Miladinović
- Department of Computer Science, ETH Zurich, Zürich, Switzerland
- Max Planck Institute for Intelligent Systems, Tübingen, Germany
| | - Christine Muheim
- Chronobiology and Sleep Research Group, University of Zurich, Zürich, Switzerland
- Department of Biomedical Sciences, Washington State University, Spokane, Washington, United States of America
| | - Stefan Bauer
- Department of Computer Science, ETH Zurich, Zürich, Switzerland
- Max Planck Institute for Intelligent Systems, Tübingen, Germany
| | - Andrea Spinnler
- Chronobiology and Sleep Research Group, University of Zurich, Zürich, Switzerland
| | - Daniela Noain
- Department of Neurology, University Hospital Zurich, Zürich, Switzerland
| | | | | | | | - Christian Baumann
- Department of Neurology, University Hospital Zurich, Zürich, Switzerland
| | | | - Steven A. Brown
- Chronobiology and Sleep Research Group, University of Zurich, Zürich, Switzerland
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Goonawardena AV, Morairty SR, Orellana GA, Willoughby AR, Wallace TL, Kilduff TS. Electrophysiological characterization of sleep/wake, activity and the response to caffeine in adult cynomolgus macaques. Neurobiol Sleep Circadian Rhythms 2019; 6:9-23. [PMID: 31236518 PMCID: PMC6586594 DOI: 10.1016/j.nbscr.2018.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 08/11/2018] [Accepted: 08/14/2018] [Indexed: 12/29/2022] Open
Abstract
Most preclinical sleep studies are conducted in nocturnal rodents that have fragmented sleep in comparison to humans who are primarily diurnal, typically with a consolidated sleep period. Consequently, we sought to define basal sleep characteristics, sleep/wake architecture and electroencephalographic (EEG) activity in a diurnal non-human primate (NHP) to evaluate the utility of this species for pharmacological manipulation of the sleep/wake cycle. Adult, 9-11 y.o. male cynomolgus macaques (n = 6) were implanted with telemetry transmitters to record EEG and electromyogram (EMG) activity and Acticals to assess locomotor activity under baseline conditions and following injections either with vehicle or the caffeine (CAF; 10 mg/kg, i.m.) prior to the 12 h dark phase. EEG/EMG recordings (12-36 h in duration) were analyzed for sleep/wake states and EEG spectral composition. Macaques exhibited a sleep state distribution and architecture similar to previous NHP and human sleep studies. Acute administration of CAF prior to light offset enhanced wakefulness nearly 4-fold during the dark phase with consequent reductions in both NREM and REM sleep, decreased slow wave activity during wakefulness, and increased higher EEG frequency activity during NREM sleep. Despite the large increase in wakefulness and profound reduction in sleep during the dark phase, no sleep rebound was observed during the 24 h light and dark phases following caffeine administration. Cynomolgus macaques show sleep characteristics, EEG spectral structure, and respond to CAF in a similar manner to humans. Consequently, monitoring EEG/EMG by telemetry in this species may be useful both for basic sleep/wake studies and for pre-clinical assessments of drug-induced effects on sleep/wake.
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Key Words
- A1, Adenosine sub-type 1 receptor
- A2a, Adenosine sub-type 2 receptor
- CAF, Caffeine
- Caffeine
- Cynomolgus macaque
- EEG
- EEG, Electroencephalogram
- EMG, Electromyogram
- LMA, Locomotor activity
- N1, NREM Stage 1
- N2, NREM Stage 2
- N3, NREM Stage 3
- NHP, Non-human primate
- NREM
- NREM, Non-rapid eye movement
- REM
- REM, Rapid eye movement
- ROL, REM onset latency
- SEM, Standard error of mean
- SOL, Sleep onset latency
- Sleep
- TST, Total sleep time
- WASO, Wake after sleep onset
- i.m., Intramuscular
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Affiliation(s)
| | | | | | | | | | - Thomas S. Kilduff
- Center for Neuroscience, Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA
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14
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Donlea JM. Roles for sleep in memory: insights from the fly. Curr Opin Neurobiol 2018; 54:120-126. [PMID: 30366270 DOI: 10.1016/j.conb.2018.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/04/2018] [Indexed: 01/10/2023]
Abstract
Sleep has been universally conserved across animal species. The basic functions of sleep remain unclear, but insufficient sleep impairs memory acquisition and retention in both vertebrates and invertebrates. Sleep is also a homeostatic process that is influenced not only by the amount of time awake, but also by neural activity and plasticity. Because of the breadth and precision of available genetic tools, the fruit fly has become a powerful model system to understand sleep regulation and function. Importantly, these tools enable the dissection of memory-encoding circuits at the level of individual neurons, and have allowed the development of genetic tools to induce sleep on-demand. This review describes recent investigations of the role for sleep in memory using Drosophila and current hypotheses of sleep's functions for supporting plasticity, learning, and memory.
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Affiliation(s)
- Jeffrey M Donlea
- Department of Neurobiology, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
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15
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Abstract
Sleep is nearly ubiquitous throughout the animal kingdom, yet little is known about how ecological factors or perturbations to the environment shape the duration and timing of sleep. In diverse animal taxa, poor sleep negatively impacts development, cognitive abilities and longevity. In addition to mammals, sleep has been characterized in genetic model organisms, ranging from the nematode worm to zebrafish, and, more recently, in emergent models with simplified nervous systems such as Aplysia and jellyfish. In addition, evolutionary models ranging from fruit flies to cavefish have leveraged natural genetic variation to investigate the relationship between ecology and sleep. Here, we describe the contributions of classical and emergent genetic model systems to investigate mechanisms underlying sleep regulation. These studies highlight fundamental interactions between sleep and sensory processing, as well as a remarkable plasticity of sleep in response to environmental changes. Understanding how sleep varies throughout the animal kingdom will provide critical insight into fundamental functions and conserved genetic mechanisms underlying sleep regulation. Furthermore, identification of naturally occurring genetic variation regulating sleep may provide novel drug targets and approaches to treat sleep-related diseases.
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Affiliation(s)
- Alex C Keene
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, FL 33458, USA
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Erik R Duboue
- Jupiter Life Science Initiative, Florida Atlantic University, Jupiter, FL 33458, USA
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
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16
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Eban-Rothschild A, Appelbaum L, de Lecea L. Neuronal Mechanisms for Sleep/Wake Regulation and Modulatory Drive. Neuropsychopharmacology 2018; 43:937-952. [PMID: 29206811 PMCID: PMC5854814 DOI: 10.1038/npp.2017.294] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/17/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
Abstract
Humans have been fascinated by sleep for millennia. After almost a century of scientific interrogation, significant progress has been made in understanding the neuronal regulation and functions of sleep. The application of new methods in neuroscience that enable the analysis of genetically defined neuronal circuits with unprecedented specificity and precision has been paramount in this endeavor. In this review, we first discuss electrophysiological and behavioral features of sleep/wake states and the principal neuronal populations involved in their regulation. Next, we describe the main modulatory drives of sleep and wakefulness, including homeostatic, circadian, and motivational processes. Finally, we describe a revised integrative model for sleep/wake regulation.
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Affiliation(s)
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
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17
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Blum ID, Bell B, Wu MN. Time for Bed: Genetic Mechanisms Mediating the Circadian Regulation of Sleep. Trends Genet 2018; 34:379-388. [PMID: 29395381 DOI: 10.1016/j.tig.2018.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 10/18/2022]
Abstract
Sleep is an evolutionarily conserved behavior that is increasingly recognized as important for human health. While its precise function remains controversial, sleep has been suggested to play a key role in a variety of biological phenomena ranging from synaptic plasticity to metabolic clearance. Although it is clear that sleep is regulated by the circadian clock, how this occurs remains enigmatic. Here we examine the genetic mechanisms by which the circadian clock regulates sleep, drawing on recent work in fruit flies, zebrafish, mice, and humans. These studies reveal that central and local clocks utilize diverse mechanisms to regulate different aspects of sleep, and a better understanding of this multilayered regulation may lead to a better understanding of the functions of sleep.
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Affiliation(s)
- Ian D Blum
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Benjamin Bell
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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18
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Abstract
Despite decades of intense study, the functions of sleep are still shrouded in mystery. The difficulty in understanding these functions can be at least partly attributed to the varied manifestations of sleep in different animals. Daily sleep duration can range from 4-20 hrs among mammals, and sleep can manifest throughout the brain, or it can alternate over time between cerebral hemispheres, depending on the species. Ecological factors are likely to have shaped these and other sleep behaviors during evolution by altering the properties of conserved arousal circuits in the brain. Nonetheless, core functions of sleep are likely to have arisen early and to have persisted to the present day in diverse organisms. This review will discuss the evolutionary forces that may be responsible for phylogenetic differences in sleep and the potential core functions that sleep fulfills.
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Affiliation(s)
- William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0636, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0636, USA; Center for Circadian Biology, University of California San Diego, La Jolla, CA 92093-0636, USA.
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19
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Jaggard J, Robinson BG, Stahl BA, Oh I, Masek P, Yoshizawa M, Keene AC. The lateral line confers evolutionarily derived sleep loss in the Mexican cavefish. ACTA ACUST UNITED AC 2017; 220:284-293. [PMID: 28100806 DOI: 10.1242/jeb.145128] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/23/2016] [Indexed: 01/19/2023]
Abstract
Sleep is an essential behavior exhibited by nearly all animals, and disruption of this process is associated with an array of physiological and behavioral deficits. Sleep is defined by changes in sensory gating that reduce sensory input to the brain, but little is known about the neural basis for interactions between sleep and sensory processing. Blind Mexican cavefish comprise an extant surface dwelling form and 29 cave morphs that have independently evolved increased numbers of mechanoreceptive lateral line neuromasts and convergent evolution of sleep loss. Ablation of the lateral line enhanced sleep in the Pachón cavefish population, suggesting that heightened sensory input underlies evolutionarily derived sleep loss. Targeted lateral line ablation and behavioral analysis localized the wake-promoting neuromasts in Pachón cavefish to superficial neuromasts of the trunk and cranial regions. Strikingly, lateral line ablation did not affect sleep in four other cavefish populations, suggesting that distinct neural mechanisms regulate the evolution of sleep loss in independently derived cavefish populations. Cavefish are subject to seasonal changes in food availability, raising the possibility that sensory modulation of sleep is influenced by metabolic state. We found that starvation promotes sleep in Pachón cavefish, and is not enhanced by lateral line ablation, suggesting that functional interactions occur between sensory and metabolic regulation of sleep. Taken together, these findings support a model where sensory processing contributes to evolutionarily derived changes in sleep that are modulated in accordance with food availability.
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Affiliation(s)
- James Jaggard
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Beatriz G Robinson
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Bethany A Stahl
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Ian Oh
- Davidson Academy of Nevada, Reno, NV 89557, USA
| | - Pavel Masek
- Department of Biology, SUNY Binghamton, Binghamton, NY 13902, USA
| | - Masato Yoshizawa
- Department of Biology, University of Hawaii, Manoa, Honolulu, HI 96822, USA
| | - Alex C Keene
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
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20
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Vorster APA, Born J. Sleep supports inhibitory operant conditioning memory in Aplysia. ACTA ACUST UNITED AC 2017; 24:252-256. [PMID: 28507034 PMCID: PMC5435883 DOI: 10.1101/lm.045054.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/19/2017] [Indexed: 12/21/2022]
Abstract
Sleep supports memory consolidation as shown in mammals and invertebrates such as bees and Drosophila. Here, we show that sleep's memory function is preserved in Aplysia californica with an even simpler nervous system. Animals performed on an inhibitory conditioning task ("learning that a food is inedible") three times, at Training, Retrieval 1, and Retrieval 2, with 17-h intervals between tests. Compared with Wake animals, remaining awake between Training and Retrieval 1, Sleep animals with undisturbed post-training sleep, performed significantly better at Retrieval 1 and 2. Control experiments testing retrieval only after ∼34 h, confirmed the consolidating effect of sleep occurring within 17 h after training.
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Affiliation(s)
- Albrecht P A Vorster
- Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany.,Graduate Training Centre of Neuroscience (GTC)/International Max Planck Research School (IMPRS) at the University of Tübingen, 72076 Tübingen, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology and Center for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany
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21
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Levy R, Levitan D, Susswein AJ. New learning while consolidating memory during sleep is actively blocked by a protein synthesis dependent process. eLife 2016; 5:e17769. [PMID: 27919318 PMCID: PMC5140267 DOI: 10.7554/elife.17769] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/14/2016] [Indexed: 12/16/2022] Open
Abstract
Brief experiences while a memory is consolidated may capture the consolidation, perhaps producing a maladaptive memory, or may interrupt the consolidation. Since consolidation occurs during sleep, even fleeting experiences when animals are awakened may produce maladaptive long-term memory, or may interrupt consolidation. In a learning paradigm affecting Aplysia feeding, when animals were trained after being awakened from sleep, interactions between new experiences and consolidation were prevented by blocking long-term memory arising from the new experiences. Inhibiting protein synthesis eliminated the block and allowed even a brief, generally ineffective training to produce long-term memory. Memory formation depended on consolidative proteins already expressed before training. After effective training, long term memory required subsequent transcription and translation. Memory formation during the sleep phase was correlated with increased CREB1 transcription, but not CREB2 transcription. Increased C/EBP transcription was a correlate of both effective and ineffective training and of treatments not producing memory.
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Affiliation(s)
- Roi Levy
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - David Levitan
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Abraham J Susswein
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
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22
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Krishnan HC, Gandour CE, Ramos JL, Wrinkle MC, Sanchez-Pacheco JJ, Lyons LC. Acute Sleep Deprivation Blocks Short- and Long-Term Operant Memory in Aplysia. Sleep 2016; 39:2161-2171. [PMID: 27748243 DOI: 10.5665/sleep.6320] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/08/2016] [Indexed: 01/11/2023] Open
Abstract
STUDY OBJECTIVES Insufficient sleep in individuals appears increasingly common due to the demands of modern work schedules and technology use. Consequently, there is a growing need to understand the interactions between sleep deprivation and memory. The current study determined the effects of acute sleep deprivation on short and long-term associative memory using the marine mollusk Aplysia californica, a relatively simple model system well known for studies of learning and memory. METHODS Aplysia were sleep deprived for 9 hours using context changes and tactile stimulation either prior to or after training for the operant learning paradigm, learning that food is inedible (LFI). The effects of sleep deprivation on short-term (STM) and long-term memory (LTM) were assessed. RESULTS Acute sleep deprivation prior to LFI training impaired the induction of STM and LTM with persistent effects lasting at least 24 h. Sleep deprivation immediately after training blocked the consolidation of LTM. However, sleep deprivation following the period of molecular consolidation did not affect memory recall. Memory impairments were independent of handling-induced stress, as daytime handled control animals demonstrated no memory deficits. Additional training immediately after sleep deprivation failed to rescue the induction of memory, but additional training alleviated the persistent impairment in memory induction when training occurred 24 h following sleep deprivation. CONCLUSIONS Acute sleep deprivation inhibited the induction and consolidation, but not the recall of memory. These behavioral studies establish Aplysia as an effective model system for studying the interactions between sleep and memory formation.
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Affiliation(s)
- Harini C Krishnan
- Department of Biological Science, Florida State University, Tallahassee, FL.,Program in Neuroscience, Florida State University, Tallahassee, FL
| | | | - Joshua L Ramos
- Department of Biological Science, Florida State University, Tallahassee, FL
| | - Mariah C Wrinkle
- Department of Biological Science, Florida State University, Tallahassee, FL
| | | | - Lisa C Lyons
- Department of Biological Science, Florida State University, Tallahassee, FL.,Program in Neuroscience, Florida State University, Tallahassee, FL
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23
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Chronic sleep deprivation differentially affects short and long-term operant memory in Aplysia. Neurobiol Learn Mem 2016; 134 Pt B:349-59. [PMID: 27555235 DOI: 10.1016/j.nlm.2016.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/12/2016] [Accepted: 08/18/2016] [Indexed: 12/31/2022]
Abstract
The induction, formation and maintenance of memory represent dynamic processes modulated by multiple factors including the circadian clock and sleep. Chronic sleep restriction has become common in modern society due to occupational and social demands. Given the impact of cognitive impairments associated with sleep deprivation, there is a vital need for a simple animal model in which to study the interactions between chronic sleep deprivation and memory. We used the marine mollusk Aplysia californica, with its simple nervous system, nocturnal sleep pattern and well-characterized learning paradigms, to assess the effects of two chronic sleep restriction paradigms on short-term (STM) and long-term (LTM) associative memory. The effects of sleep deprivation on memory were evaluated using the operant learning paradigm, learning that food is inedible, in which the animal associates a specific netted seaweed with failed swallowing attempts. We found that two nights of 6h sleep deprivation occurring during the first or last half of the night inhibited both STM and LTM. Moreover, the impairment in STM persisted for more than 24h. A milder, prolonged sleep deprivation paradigm consisting of 3 consecutive nights of 4h sleep deprivation also blocked STM, but had no effect on LTM. These experiments highlight differences in the sensitivity of STM and LTM to chronic sleep deprivation. Moreover, these results establish Aplysia as a valid model for studying the interactions between chronic sleep deprivation and associative memory paving the way for future studies delineating the mechanisms through which sleep restriction affects memory formation.
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24
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Yang CY, Yu K, Wang Y, Chen SA, Liu DD, Wang ZY, Su YN, Yang SZ, Chen TT, Livnat I, Vilim FS, Cropper EC, Weiss KR, Sweedler JV, Jing J. Aplysia Locomotion: Network and Behavioral Actions of GdFFD, a D-Amino Acid-Containing Neuropeptide. PLoS One 2016; 11:e0147335. [PMID: 26796097 PMCID: PMC4721866 DOI: 10.1371/journal.pone.0147335] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 01/01/2016] [Indexed: 12/02/2022] Open
Abstract
One emerging principle is that neuromodulators, such as neuropeptides, regulate multiple behaviors, particularly motivated behaviors, e.g., feeding and locomotion. However, how neuromodulators act on multiple neural networks to exert their actions remains poorly understood. These actions depend on the chemical form of the peptide, e.g., an alternation of L- to D- form of an amino acid can endow the peptide with bioactivity, as is the case for the Aplysia peptide GdFFD (where dF indicates D-phenylalanine). GdFFD has been shown to act as an extrinsic neuromodulator in the feeding network, while the all L-amino acid form, GFFD, was not bioactive. Given that both GdFFD/GFFD are also present in pedal neurons that mediate locomotion, we sought to determine whether they impact locomotion. We first examined effects of both peptides on isolated ganglia, and monitored fictive programs using the parapedal commissural nerve (PPCN). Indeed, GdFFD was bioactive and GFFD was not. GdFFD increased the frequency with which neural activity was observed in the PPCN. In part, there was an increase in bursting spiking activity that resembled fictive locomotion. Additionally, there was significant activity between bursts. To determine how the peptide-induced activity in the isolated CNS is translated into behavior, we recorded animal movements, and developed a computer program to automatically track the animal and calculate the path of movement and velocity of locomotion. We found that GdFFD significantly reduced locomotion and induced a foot curl. These data suggest that the increase in PPCN activity observed in the isolated CNS during GdFFD application corresponds to a reduction, rather than an increase, in locomotion. In contrast, GFFD had no effect. Thus, our study suggests that GdFFD may act as an intrinsic neuromodulator in the Aplysia locomotor network. More generally, our study indicates that physiological and behavioral analyses should be combined to evaluate peptide actions.
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Affiliation(s)
- Chao-Yu Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ke Yu
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ye Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Song-An Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Dan-Dan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Zheng-Yang Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Yan-Nan Su
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Shao-Zhong Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Ting-Ting Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Itamar Livnat
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Ferdinand S. Vilim
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Elizabeth C. Cropper
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Klaudiusz R. Weiss
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jonathan V. Sweedler
- Beckman Institute for Advanced Science and Technology and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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25
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Feld GB, Diekelmann S. Sleep smart-optimizing sleep for declarative learning and memory. Front Psychol 2015; 6:622. [PMID: 26029150 PMCID: PMC4428077 DOI: 10.3389/fpsyg.2015.00622] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 04/27/2015] [Indexed: 02/05/2023] Open
Abstract
The last decade has witnessed a spurt of new publications documenting sleep's essential contribution to the brains ability to form lasting memories. For the declarative memory domain, slow wave sleep (the deepest sleep stage) has the greatest beneficial effect on the consolidation of memories acquired during preceding wakefulness. The finding that newly encoded memories become reactivated during subsequent sleep fostered the idea that reactivation leads to the strengthening and transformation of the memory trace. According to the active system consolidation account, trace reactivation leads to the redistribution of the transient memory representations from the hippocampus to the long-lasting knowledge networks of the cortex. Apart from consolidating previously learned information, sleep also facilitates the encoding of new memories after sleep, which probably relies on the renormalization of synaptic weights during sleep as suggested by the synaptic homeostasis theory. During wakefulness overshooting potentiation causes an imbalance in synaptic weights that is countered by synaptic downscaling during subsequent sleep. This review briefly introduces the basic concepts and central findings of the research on sleep and memory, and discusses implications of this lab-based work for everyday applications to make the best possible use of sleep's beneficial effect on learning and memory.
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Affiliation(s)
- Gordon B Feld
- Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
| | - Susanne Diekelmann
- Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
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26
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Michel M, Lyons LC. Unraveling the complexities of circadian and sleep interactions with memory formation through invertebrate research. Front Syst Neurosci 2014; 8:133. [PMID: 25136297 PMCID: PMC4120776 DOI: 10.3389/fnsys.2014.00133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/07/2014] [Indexed: 12/14/2022] Open
Abstract
Across phylogeny, the endogenous biological clock has been recognized as providing adaptive advantages to organisms through coordination of physiological and behavioral processes. Recent research has emphasized the role of circadian modulation of memory in generating peaks and troughs in cognitive performance. The circadian clock along with homeostatic processes also regulates sleep, which itself impacts the formation and consolidation of memory. Thus, the circadian clock, sleep and memory form a triad with ongoing dynamic interactions. With technological advances and the development of a global 24/7 society, understanding the mechanisms underlying these connections becomes pivotal for development of therapeutic treatments for memory disorders and to address issues in cognitive performance arising from non-traditional work schedules. Invertebrate models, such as Drosophila melanogaster and the mollusks Aplysia and Lymnaea, have proven invaluable tools for identification of highly conserved molecular processes in memory. Recent research from invertebrate systems has outlined the influence of sleep and the circadian clock upon synaptic plasticity. In this review, we discuss the effects of the circadian clock and sleep on memory formation in invertebrates drawing attention to the potential of in vivo and in vitro approaches that harness the power of simple invertebrate systems to correlate individual cellular processes with complex behaviors. In conclusion, this review highlights how studies in invertebrates with relatively simple nervous systems can provide mechanistic insights into corresponding behaviors in higher organisms and can be used to outline possible therapeutic options to guide further targeted inquiry.
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Affiliation(s)
- Maximilian Michel
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine Nashville, TN, USA
| | - Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University Tallahassee, FL, USA
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