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Badal KK, Sadhu A, Raveendra BL, McCracken C, Lozano-Villada S, Shetty AC, Gillette P, Zhao Y, Stommes D, Fieber LA, Schmale MC, Mahurkar A, Hawkins RD, Puthanveettil SV. Single-neuron analysis of aging-associated changes in learning reveals impairments in transcriptional plasticity. Aging Cell 2024:e14228. [PMID: 38924663 DOI: 10.1111/acel.14228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 05/02/2024] [Indexed: 06/28/2024] Open
Abstract
The molecular mechanisms underlying age-related declines in learning and long-term memory are still not fully understood. To address this gap, our study focused on investigating the transcriptional landscape of a singularly identified motor neuron L7 in Aplysia, which is pivotal in a specific type of nonassociative learning known as sensitization of the siphon-withdraw reflex. Employing total RNAseq analysis on a single isolated L7 motor neuron after short-term or long-term sensitization (LTS) training of Aplysia at 8, 10, and 12 months (representing mature, late mature, and senescent stages), we uncovered aberrant changes in transcriptional plasticity during the aging process. Our findings specifically highlight changes in the expression of messenger RNAs (mRNAs) that encode transcription factors, translation regulators, RNA methylation participants, and contributors to cytoskeletal rearrangements during learning and long noncoding RNAs (lncRNAs). Furthermore, our comparative gene expression analysis identified distinct transcriptional alterations in two other neurons, namely the motor neuron L11 and the giant cholinergic neuron R2, whose roles in LTS are not yet fully elucidated. Taken together, our analyses underscore cell type-specific impairments in the expression of key components related to learning and memory within the transcriptome as organisms age, shedding light on the complex molecular mechanisms driving cognitive decline during aging.
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Affiliation(s)
- Kerriann K Badal
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
- Integrated Biology Graduate Program, Florida Atlantic University, Jupiter, Florida, USA
| | - Abhishek Sadhu
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Bindu L Raveendra
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Carrie McCracken
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sebastian Lozano-Villada
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
- Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, Florida, USA
| | - Amol C Shetty
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Phillip Gillette
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Yibo Zhao
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
| | - Dustin Stommes
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Lynne A Fieber
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Michael C Schmale
- National Resource for Aplysia, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Sciences, Miami, Florida, USA
| | - Anup Mahurkar
- The Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Robert D Hawkins
- Department of Neuroscience, Columbia University, New York, New York, USA
- New York State Psychiatric Institute, New York, New York, USA
| | - Sathyanarayanan V Puthanveettil
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, Florida, USA
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Hurwitz I, Tam S, Jing J, Chiel HJ, Gill J, Susswein AJ. Multiple changes in connectivity between buccal ganglia mechanoafferents and motor neurons with different functions after learning that food is inedible in Aplysia. Learn Mem 2024; 31:a053882. [PMID: 38950977 PMCID: PMC11261210 DOI: 10.1101/lm.053882.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 04/19/2024] [Indexed: 07/03/2024]
Abstract
Changes caused by learning that a food is inedible in Aplysia were examined for fast and slow synaptic connections from the buccal ganglia S1 cluster of mechanoafferents to five followers, in response to repeated stimulus trains. Learning affected only fast connections. For these, unique patterns of change were present in each follower, indicating that learning differentially affects the different branches of the mechanoafferents to their followers. In some followers, there were increases in either excitatory or inhibitory connections, and in others, there were decreases. Changes in connectivity resulted from changes in the amplitude of excitation or inhibition, or as a result of the number of connections, or of both. Some followers also exhibited changes in either within or between stimulus train plasticity as a result of learning. In one follower, changes differed from the different areas of the S1 cluster. The patterns of changes in connectivity were consistent with the behavioral changes produced by learning, in that they would produce an increase in the bias to reject or to release food, and a decrease in the likelihood to respond to food.
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Affiliation(s)
- Itay Hurwitz
- Gonda (Goldschmied) Brain Res Center and Goodman Faculty of Life Science, Bar Ilan University, Ramat Gan 52900, Israel
| | - Shlomit Tam
- Gonda (Goldschmied) Brain Res Center and Goodman Faculty of Life Science, Bar Ilan University, Ramat Gan 52900, Israel
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Institute for Brain Sciences, School Life Sciences, Nanjing University, Jiangsu 210023, China
| | - Hillel J Chiel
- Departments of Biology, Case Western Reserve University, Cleveland, Ohio 44106-7080, USA
- Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106-7080, USA
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7080, USA
| | - Jeffrey Gill
- Departments of Biology, Case Western Reserve University, Cleveland, Ohio 44106-7080, USA
| | - Abraham J Susswein
- Gonda (Goldschmied) Brain Res Center and Goodman Faculty of Life Science, Bar Ilan University, Ramat Gan 52900, Israel
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Brown JW, Berg OH, Boutko A, Stoerck C, Boersma MA, Frost WN. Division of labor for defensive retaliation and preemption by the peripheral and central nervous systems in the nudibranch Berghia. Curr Biol 2024; 34:2175-2185.e4. [PMID: 38718797 DOI: 10.1016/j.cub.2024.04.038] [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: 07/26/2023] [Revised: 01/02/2024] [Accepted: 04/15/2024] [Indexed: 05/23/2024]
Abstract
Relatively little is known about how peripheral nervous systems (PNSs) contribute to the patterning of behavior in which their role transcends the simple execution of central motor commands or mediation of reflexes. We sought to draw inferences to this end in the aeolid nudibranch Berghia stephanieae, which generates a rapid, dramatic defense behavior, "bristling." This behavior involves the coordinated movement of cerata, dozens of venomous appendages emerging from the animal's mantle. Our investigations revealed that bristling constitutes a stereotyped but non-reflexive two-stage behavior: an initial adduction of proximate cerata to sting the offending stimulus (stage 1) followed by a coordinated radial extension of remaining cerata to create a pincushion-like defensive screen around the animal (stage 2). In decerebrated specimens, stage 1 bristling was preserved, while stage 2 bristling was replaced by slower, uncoordinated ceratal movements. We conclude from these observations that, first, the animal's PNS and central nervous system (CNS) mediate stages 1 and 2 of bristling, respectively; second, the behavior propagates through the body utilizing both peripheral- and central-origin nerve networks that support different signaling kinetics; and third, the former network inhibits the latter in the body region being stimulated. These findings extend our understanding of the PNS' computational capacity and provide insight into a neuroethological scheme in which the CNS and PNS both independently and interactively pattern different aspects of non-reflexive behavior.
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Affiliation(s)
- Jeffrey W Brown
- Stanson Toshok Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Ondine H Berg
- Neuroscience Program, Lake Forest College, Lake Forest, IL 60045, USA
| | - Anastasiya Boutko
- The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Cody Stoerck
- Department of Psychology, California State University at Fullerton, Fullerton, CA 92831, USA
| | | | - William N Frost
- Stanson Toshok Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
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Rahmani A, McMillen A, Allen E, Minervini C, Chew YL. Behavioral Tests for Associative Learning in Caenorhabditis elegans. Methods Mol Biol 2024; 2746:21-46. [PMID: 38070077 DOI: 10.1007/978-1-0716-3585-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Learning is critical for survival as it provides the capacity to adapt to a changing environment. At the molecular and cellular level, learning leads to alterations within neural circuits that include synaptic rewiring, synaptic plasticity, and protein level/gene expression changes. There has been substantial progress in recent years on dissecting how learning and memory is regulated at the molecular and cellular level, including the use of compact invertebrate nervous systems as experimental models. This progress has been facilitated by the establishment of robust behavioral assays that generate a quantifiable readout of the extent to which animals learn and remember. This chapter will focus on protocols of behavioral tests for associative learning using the nematode Caenorhabditis elegans, with its unparalleled genetic tractability, compact nervous system of ~300 neurons, high level of conservation with mammalian systems, and amenability to a suite of behavioral tools and analyses. Specifically, we will provide a detailed description of the methods for two behavioral assays that model associative learning, one measuring appetitive olfactory learning and the other assaying aversive gustatory learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Anna McMillen
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Ericka Allen
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Caitlin Minervini
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.
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Zhang XO, Zhang Y, Cho CE, Engelke DS, Smolen P, Byrne JH, Do-Monte FH. Enhancing Associative Learning in Rats With a Computationally Designed Training Protocol. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:165-181. [PMID: 38298784 PMCID: PMC10829654 DOI: 10.1016/j.bpsgos.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/30/2023] [Accepted: 07/20/2023] [Indexed: 02/02/2024] Open
Abstract
Background Learning requires the activation of protein kinases with distinct temporal dynamics. In Aplysia, nonassociative learning can be enhanced by a computationally designed learning protocol with intertrial intervals (ITIs) that maximize the interaction between fast-activated PKA (protein kinase A) and slow-activated ERK (extracellular signal-regulated kinase). Whether a similar strategy can enhance associative learning in mammals is unknown. Methods We simulated 1000 training protocols with varying ITIs to predict an optimal protocol based on empirical data for PKA and ERK dynamics in rat hippocampus. Adult male rats received the optimal protocol or control protocols in auditory fear conditioning and fear extinction experiments. Immunohistochemistry was performed to evaluate pCREB (phosphorylated cAMP response element binding)\protein levels in brain regions that have been implicated in fear acquisition. Results Rats exposed to the optimal conditioning protocol with irregular ITIs exhibited impaired extinction memory acquisition within the session using a standard footshock intensity, and stronger fear memory retrieval and spontaneous recovery with a weaker footshock intensity, compared with rats that received massed or spaced conditioning protocols with fixed ITIs. Rats exposed to the optimal extinction protocol displayed improved extinction of contextual fear memory and reduced spontaneous recovery compared with rats that received standard extinction protocols. Moreover, the optimal conditioning protocol increased pCREB levels in the dentate gyrus of the dorsal hippocampus, suggesting enhanced induction of long-term potentiation. Conclusions These findings demonstrate that a computational model-driven behavioral intervention can enhance associative learning in mammals and may provide insight into strategies to improve cognition in humans.
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Affiliation(s)
- Xu O. Zhang
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Yili Zhang
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Claire E. Cho
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Douglas S. Engelke
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Paul Smolen
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - John H. Byrne
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Fabricio H. Do-Monte
- Department of Neurobiology and Anatomy, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
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Lang B, Kahnau P, Hohlbaum K, Mieske P, Andresen NP, Boon MN, Thöne-Reineke C, Lewejohann L, Diederich K. Challenges and advanced concepts for the assessment of learning and memory function in mice. Front Behav Neurosci 2023; 17:1230082. [PMID: 37809039 PMCID: PMC10551171 DOI: 10.3389/fnbeh.2023.1230082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
The mechanisms underlying the formation and retrieval of memories are still an active area of research and discussion. Manifold models have been proposed and refined over the years, with most assuming a dichotomy between memory processes involving non-conscious and conscious mechanisms. Despite our incomplete understanding of the underlying mechanisms, tests of memory and learning count among the most performed behavioral experiments. Here, we will discuss available protocols for testing learning and memory using the example of the most prevalent animal species in research, the laboratory mouse. A wide range of protocols has been developed in mice to test, e.g., object recognition, spatial learning, procedural memory, sequential problem solving, operant- and fear conditioning, and social recognition. Those assays are carried out with individual subjects in apparatuses such as arenas and mazes, which allow for a high degree of standardization across laboratories and straightforward data interpretation but are not without caveats and limitations. In animal research, there is growing concern about the translatability of study results and animal welfare, leading to novel approaches beyond established protocols. Here, we present some of the more recent developments and more advanced concepts in learning and memory testing, such as multi-step sequential lockboxes, assays involving groups of animals, as well as home cage-based assays supported by automated tracking solutions; and weight their potential and limitations against those of established paradigms. Shifting the focus of learning tests from the classical experimental chamber to settings which are more natural for rodents comes with a new set of challenges for behavioral researchers, but also offers the opportunity to understand memory formation and retrieval in a more conclusive way than has been attainable with conventional test protocols. We predict and embrace an increase in studies relying on methods involving a higher degree of automatization, more naturalistic- and home cage-based experimental setting as well as more integrated learning tasks in the future. We are confident these trends are suited to alleviate the burden on animal subjects and improve study designs in memory research.
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Affiliation(s)
- Benjamin Lang
- Animal Behavior and Laboratory Animal Science, Department of Veterinary Medicine, Institute for Animal Welfare, Free University of Berlin, Berlin, Germany
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
| | - Pia Kahnau
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Katharina Hohlbaum
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Paul Mieske
- Animal Behavior and Laboratory Animal Science, Department of Veterinary Medicine, Institute for Animal Welfare, Free University of Berlin, Berlin, Germany
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Niek P. Andresen
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
- Computer Vision and Remote Sensing, Technical University Berlin, Berlin, Germany
| | - Marcus N. Boon
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
- Modeling of Cognitive Processes, Technical University of Berlin, Berlin, Germany
| | - Christa Thöne-Reineke
- Animal Behavior and Laboratory Animal Science, Department of Veterinary Medicine, Institute for Animal Welfare, Free University of Berlin, Berlin, Germany
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
| | - Lars Lewejohann
- Animal Behavior and Laboratory Animal Science, Department of Veterinary Medicine, Institute for Animal Welfare, Free University of Berlin, Berlin, Germany
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Kai Diederich
- Federal Institute for Risk Assessment (BfR), Berlin, Germany
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7
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Brown JW, Berg OH, Boutko A, Stoerck C, Boersma MA, Frost WN. Neural division of labor: the gastropod Berghia defends against attack using its PNS to retaliate and its CNS to erect a defensive screen. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.29.551068. [PMID: 37577477 PMCID: PMC10418079 DOI: 10.1101/2023.07.29.551068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Relatively little is known about how the peripheral nervous system (PNS) contributes to the patterning of behavior, in which its role transcends the simple execution of central motor commands or mediation of reflexes. We sought to draw inferences to this end in the aeolid nudibranch Berghia stephanieae, which generates a rapid, dramatic defense behavior, "bristling." This behavior involves the coordinated movement of cerata, dozens of venomous appendages emerging from the animal's mantle. Our investigations revealed that bristling constitutes a stereotyped but non-reflexive two-stage behavior: an initial adduction of proximate cerata to sting the offending stimulus (Stage 1), followed by a coordinated radial extension of remaining cerata to create a pincushion-like defensive screen around the animal (Stage 2). In decerebrated specimens, Stage 1 bristling was preserved, while Stage 2 bristling was replaced by slower, uncoordinated, and ultimately maladaptive ceratal movements. We conclude from these observations that 1) the PNS and central nervous system (CNS) mediate Stages 1 and 2 of bristling, respectively; 2) the behavior propagates through the body utilizing both peripheral- and central-origin nerve networks that support different signaling kinetics; and 3) the former network inhibits the latter in the body region being stimulated. These findings extend our understanding of the PNS's computational capacity and provide insight into a neuroethological scheme that may generalize across cephalized animals, in which the CNS and PNS both independently and interactively pattern different aspects of non-reflexive behavior.
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Affiliation(s)
- Jeffrey W. Brown
- Stanson Toshok Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
| | - Ondine H. Berg
- Neuroscience Program, Lake Forest College, Lake Forest, IL 60045
| | - Anastasiya Boutko
- The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
| | - Cody Stoerck
- Department of Psychology, California State University at Fullerton, Fullerton, CA 92831
| | | | - William N. Frost
- Stanson Toshok Center for Brain Function and Repair, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
- The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064
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Fu P, Mei YS, Liu WJ, Chen P, Jin QC, Guo SQ, Wang HY, Xu JP, Zhang YCF, Ding XY, Liu CP, Liu CY, Mao RT, Zhang G, Jing J. Identification of three elevenin receptors and roles of elevenin disulfide bond and residues in receptor activation in Aplysia californica. Sci Rep 2023; 13:7662. [PMID: 37169790 PMCID: PMC10175484 DOI: 10.1038/s41598-023-34596-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/04/2023] [Indexed: 05/13/2023] Open
Abstract
Neuropeptides are ubiquitous intercellular signaling molecules in the CNS and play diverse roles in modulating physiological functions by acting on specific G-protein coupled receptors (GPCRs). Among them, the elevenin signaling system is now believed to be present primarily in protostomes. Although elevenin was first identified from the L11 neuron of the abdominal ganglion in mollusc Aplysia californica, no receptors have been described in Aplysia, nor in any other molluscs. Here, using two elevenin receptors in annelid Platynereis dumerilii, we found three putative elevenin GPCRs in Aplysia. We cloned the three receptors and tentatively named them apElevR1, apElevR2, and apElevR3. Using an inositol monophosphate (IP1) accumulation assay, we demonstrated that Aplysia elevenin with the disulfide bond activated the three putative receptors with low EC50 values (ranging from 1.2 to 25 nM), supporting that they are true receptors for elevenin. In contrast, elevenin without the disulfide bond could not activate the receptors, indicating that the disulfide bond is required for receptor activity. Using alanine substitution of individual conserved residues other than the two cysteines, we showed that these residues appear to be critical to receptor activity, and the three different receptors had different sensitivities to the single residue substitution. Finally, we examined the roles of those residues outside the disulfide bond ring by removing these residues and found that they also appeared to be important to receptor activity. Thus, our study provides an important basis for further study of the functions of elevenin and its receptors in Aplysia and other molluscs.
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Affiliation(s)
- Ping Fu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Yu-Shuo Mei
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Wei-Jia Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Ping Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Qing-Chun Jin
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Shi-Qi Guo
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Hui-Ying Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Ju-Ping Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Yan-Chu-Fei Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Xue-Ying Ding
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Cui-Ping Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Cheng-Yi Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Rui-Ting Mao
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Guo Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China.
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medical Psychology and Neurology, Nanjing Drum Tower Hospital, Institute for Brain Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing, 210023, Jiangsu, China.
- Peng Cheng Laboratory, Shenzhen, 518000, China.
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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9
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Xu JP, Ding XY, Guo SQ, Wang HY, Liu WJ, Jiang HM, Li YD, Fu P, Chen P, Mei YS, Zhang G, Zhou HB, Jing J. Characterization of an Aplysia vasotocin signaling system and actions of posttranslational modifications and individual residues of the ligand on receptor activity. Front Pharmacol 2023; 14:1132066. [PMID: 37021048 PMCID: PMC10067623 DOI: 10.3389/fphar.2023.1132066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 03/06/2023] [Indexed: 04/07/2023] Open
Abstract
The vasopressin/oxytocin signaling system is present in both protostomes and deuterostomes and plays various physiological roles. Although there were reports for both vasopressin-like peptides and receptors in mollusc Lymnaea and Octopus, no precursor or receptors have been described in mollusc Aplysia. Here, through bioinformatics, molecular and cellular biology, we identified both the precursor and two receptors for Aplysia vasopressin-like peptide, which we named Aplysia vasotocin (apVT). The precursor provides evidence for the exact sequence of apVT, which is identical to conopressin G from cone snail venom, and contains 9 amino acids, with two cysteines at position 1 and 6, similar to nearly all vasopressin-like peptides. Through inositol monophosphate (IP1) accumulation assay, we demonstrated that two of the three putative receptors we cloned from Aplysia cDNA are true receptors for apVT. We named the two receptors as apVTR1 and apVTR2. We then determined the roles of post-translational modifications (PTMs) of apVT, i.e., the disulfide bond between two cysteines and the C-terminal amidation on receptor activity. Both the disulfide bond and amidation were critical for the activation of the two receptors. Cross-activity with conopressin S, annetocin from an annelid, and vertebrate oxytocin showed that although all three ligands can activate both receptors, the potency of these peptides differed depending on their residue variations from apVT. We, therefore, tested the roles of each residue through alanine substitution and found that each substitution could reduce the potency of the peptide analog, and substitution of the residues within the disulfide bond tended to have a larger impact on receptor activity than the substitution of those outside the bond. Moreover, the two receptors had different sensitivities to the PTMs and single residue substitutions. Thus, we have characterized the Aplysia vasotocin signaling system and showed how the PTMs and individual residues in the ligand contributed to receptor activity.
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Affiliation(s)
- Ju-Ping Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Xue-Ying Ding
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Shi-Qi Guo
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Hui-Ying Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Wei-Jia Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Hui-Min Jiang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Ya-Dong Li
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Ping Fu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Ping Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Yu-Shuo Mei
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Guo Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
| | - Hai-Bo Zhou
- School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Jian Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Chemistry and Biomedicine Innovation Center, Institute for Brain Sciences, Advanced Institute for Life Sciences, School of Life Sciences, Chinese Academy of Medical Sciences Research Unit of Extracellular RNA, Nanjing University, Nanjing, Jiangsu, China
- Peng Cheng Laboratory, Shenzhen, China
- Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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10
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Sadhu A, Badal KK, Zhao Y, Ali AA, Swarnkar S, Tsaprailis G, Crynen GC, Puthanveettil SV. Short-Term and Long-Term Sensitization Differentially Alters the Composition of an Anterograde Transport Complex in Aplysia. eNeuro 2023; 10:ENEURO.0266-22.2022. [PMID: 36549915 PMCID: PMC9829102 DOI: 10.1523/eneuro.0266-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 11/09/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022] Open
Abstract
Long-term memory formation requires anterograde transport of proteins from the soma of a neuron to its distal synaptic terminals. This allows new synaptic connections to be grown and existing ones remodeled. However, we do not yet know which proteins are transported to synapses in response to activity and temporal regulation. Here, using quantitative mass spectrometry, we have profiled anterograde protein cargos of a learning-regulated molecular motor protein kinesin [Aplysia kinesin heavy chain 1 (ApKHC1)] following short-term sensitization (STS) and long-term sensitization (LTS) in Aplysia californica Our results reveal enrichment of specific proteins associated with ApKHC1 following both STS and LTS, as well as temporal changes within 1 and 3 h of LTS training. A significant number of proteins enriched in the ApKHC1 complex participate in synaptic function, and, while some are ubiquitously enriched across training conditions, a few are enriched in response to specific training. For instance, factors aiding new synapse formation, such as synaptotagmin-1, dynamin-1, and calmodulin, are differentially enriched in anterograde complexes 1 h after LTS but are depleted 3 h after LTS. Proteins including gelsolin-like protein 2 and sec23A/sec24A, which function in actin filament stabilization and vesicle transport, respectively, are enriched in cargos 3 h after LTS. These results establish that the composition of anterograde transport complexes undergo experience-dependent specific changes and illuminate dynamic changes in the communication between soma and synapse during learning.
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Affiliation(s)
- Abhishek Sadhu
- Department of Neuroscience, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
| | - Kerriann K Badal
- Department of Neuroscience, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
- Integrated Biology Graduate Program, Florida Atlantic University, Jupiter, Florida 33458
| | - Yibo Zhao
- Department of Neuroscience, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
| | - Adia A Ali
- Department of Neuroscience, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
| | - Supriya Swarnkar
- Department of Neuroscience, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
| | - George Tsaprailis
- Proteomics Core, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
| | - Gogce C Crynen
- Bioinformatics Core, UF Scripps Biomedical Research, University of Florida, Jupiter, Florida 33458
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11
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Shomali A, Vafaei Sadi MS, Bakhtiarizadeh MR, Aliniaeifard S, Trewavas A, Calvo P. Identification of intelligence-related proteins through a robust two-layer predictor. Commun Integr Biol 2022; 15:253-264. [DOI: 10.1080/19420889.2022.2143101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Aida Shomali
- Department of Horticulture, College of Aburaihan, University of Tehran, Tehran, Iran
| | | | | | - Sasan Aliniaeifard
- Department of Horticulture, College of Aburaihan, University of Tehran, Tehran, Iran
| | - Anthony Trewavas
- School of Biological Sciences, Institute of Molecular Plant Science, University of Edinburgh, UK
| | - Paco Calvo
- Minimal Intelligence Lab, University of Murcia, Spain
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12
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Liu RY, Zhang Y, Smolen P, Cleary LJ, Byrne JH. Defective synaptic plasticity in a model of Coffin-Lowry syndrome is rescued by simultaneously targeting PKA and MAPK pathways. Learn Mem 2022; 29:435-446. [PMID: 36446603 PMCID: PMC9749851 DOI: 10.1101/lm.053625.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/24/2022] [Indexed: 12/02/2022]
Abstract
Empirical and computational methods were combined to examine whether individual or dual-drug treatments can restore the deficit in long-term synaptic facilitation (LTF) of the Aplysia sensorimotor synapse observed in a cellular model of Coffin-Lowry syndrome (CLS). The model was produced by pharmacological inhibition of p90 ribosomal S6 kinase (RSK) activity. In this model, coapplication of an activator of the mitogen-activated protein kinase (MAPK) isoform ERK and an activator of protein kinase A (PKA) resulted in enhanced phosphorylation of RSK and enhanced LTF to a greater extent than either drug alone and also greater than their additive effects, which is termed synergism. The extent of synergism appeared to depend on another MAPK isoform, p38 MAPK. Inhibition of p38 MAPK facilitated serotonin (5-HT)-induced RSK phosphorylation, indicating that p38 MAPK inhibits activation of RSK. Inhibition of p38 MAPK combined with activation of PKA synergistically activated both ERK and RSK. Our results suggest that cellular models of disorders that affect synaptic plasticity and learning, such as CLS, may constitute a useful strategy to identify candidate drug combinations, and that combining computational models with empirical tests of model predictions can help explain synergism of drug combinations.
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Affiliation(s)
- Rong-Yu Liu
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Yili Zhang
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Paul Smolen
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Leonard J Cleary
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - John H Byrne
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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13
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Zhang Y, Liu RY, Smolen P, Cleary LJ, Byrne JH. Dynamics and Mechanisms of ERK Activation after Different Protocols that Induce Long-Term Synaptic Facilitation in Aplysia. OXFORD OPEN NEUROSCIENCE 2022; 2:kvac014. [PMID: 37649778 PMCID: PMC10464504 DOI: 10.1093/oons/kvac014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/05/2022] [Indexed: 09/01/2023]
Abstract
Phosphorylation of the MAPK family member extracellular signal-regulated kinase (ERK) is required to induce long-term synaptic plasticity, but little is known about its persistence. We examined ERK activation by three protocols that induce long-term synaptic facilitation (LTF) of the Aplysia sensorimotor synapse - the standard protocol (five 5-min pulses of 5-HT with interstimulus intervals (ISIs) of 20 min), the enhanced protocol (five pulses with irregular ISIs, which induces greater and longer-lasting LTF) and the two-pulse protocol (two pulses with ISI 45 min). Immunofluorescence revealed complex ERK activation. The standard and two-pulse protocols immediately increased active, phosphorylated ERK (pERK), which decayed within 5 h. A second wave of increased pERK was detected 18 h post-treatment for all protocols. This late phase was blocked by inhibitors of protein kinase A, TrkB and TGF-β. These results suggest that complex interactions among kinase pathways and growth factors contribute to the late increase of pERK. ERK activity returned to basal 24 h after the standard or two-pulse protocols, but remained elevated 24 h for the enhanced protocol. This 24-h elevation was also dependent on PKA and TGF-β, and partly on TrkB. These results begin to characterize long-lasting ERK activation, plausibly maintained by positive feedback involving growth factors and PKA, that appears essential to maintain LTF and LTM. Because many processes involved in LTF and late LTP are conserved among Aplysia and mammals, these findings highlight the importance of examining the dynamics of kinase cascades involved in vertebrate long-term memory.
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Affiliation(s)
- Yili Zhang
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Suite MSB 7.046, Houston, TX 77030, United States
| | - Rong-Yu Liu
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Suite MSB 7.046, Houston, TX 77030, United States
| | - Paul Smolen
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Suite MSB 7.046, Houston, TX 77030, United States
| | - Leonard J Cleary
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Suite MSB 7.046, Houston, TX 77030, United States
| | - John H Byrne
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Suite MSB 7.046, Houston, TX 77030, United States
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14
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Wang C, Xu X, Pi X, Butala MD, Huang W, Yin L, Peng W, Ali M, Bodepudi SC, Qiao X, Xu Y, Sun W, Yang D. Neuromorphic device based on silicon nanosheets. Nat Commun 2022; 13:5216. [PMID: 36064545 PMCID: PMC9445003 DOI: 10.1038/s41467-022-32884-y] [Citation(s) in RCA: 2] [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: 01/05/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
Silicon is vital for its high abundance, vast production, and perfect compatibility with the well-established CMOS processing industry. Recently, artificially stacked layered 2D structures have gained tremendous attention via fine-tuning properties for electronic devices. This article presents neuromorphic devices based on silicon nanosheets that are chemically exfoliated and surface-modified, enabling self-assembly into hierarchical stacking structures. The device functionality can be switched between a unipolar memristor and a feasibly reset-able synaptic device. The memory function of the device is based on the charge storage in the partially oxidized SiNS stacks followed by the discharge activated by the electric field at the Au-Si Schottky interface, as verified in both experimental and theoretical means. This work further inspired elegant neuromorphic computation models for digit recognition and noise filtration. Ultimately, it brings silicon - the most established semiconductor - back to the forefront for next-generation computations.
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Affiliation(s)
- Chenhao Wang
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Xinyi Xu
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
- College of Information Science and Electronics Engineering, Zhejiang University, 310027, Hangzhou, PR China
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China
| | - Xiaodong Pi
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
| | - Mark D Butala
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China
| | - Wen Huang
- New Energy Technology Engineering Laboratory of Jiangsu Provence & School of Science, Nanjing University of Posts and Telecommunications, 210023, Nanjing, PR China
| | - Lei Yin
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Wenbing Peng
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Munir Ali
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
| | - Srikrishna Chanakya Bodepudi
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
| | - Xvsheng Qiao
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Yang Xu
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China.
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China.
- College of Information Science and Electronics Engineering, Zhejiang University, 310027, Hangzhou, PR China.
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China.
| | - Wei Sun
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China.
| | - Deren Yang
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China.
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15
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The evolution of synaptic and cognitive capacity: Insights from the nervous system transcriptome of Aplysia. Proc Natl Acad Sci U S A 2022; 119:e2122301119. [PMID: 35867761 PMCID: PMC9282427 DOI: 10.1073/pnas.2122301119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The gastropod mollusk Aplysia is an important model for cellular and molecular neurobiological studies, particularly for investigations of molecular mechanisms of learning and memory. We developed an optimized assembly pipeline to generate an improved Aplysia nervous system transcriptome. This improved transcriptome enabled us to explore the evolution of cognitive capacity at the molecular level. Were there evolutionary expansions of neuronal genes between this relatively simple gastropod Aplysia (20,000 neurons) and Octopus (500 million neurons), the invertebrate with the most elaborate neuronal circuitry and greatest behavioral complexity? Are the tremendous advances in cognitive power in vertebrates explained by expansion of the synaptic proteome that resulted from multiple rounds of whole genome duplication in this clade? Overall, the complement of genes linked to neuronal function is similar between Octopus and Aplysia. As expected, a number of synaptic scaffold proteins have more isoforms in humans than in Aplysia or Octopus. However, several scaffold families present in mollusks and other protostomes are absent in vertebrates, including the Fifes, Lev10s, SOLs, and a NETO family. Thus, whereas vertebrates have more scaffold isoforms from select families, invertebrates have additional scaffold protein families not found in vertebrates. This analysis provides insights into the evolution of the synaptic proteome. Both synaptic proteins and synaptic plasticity evolved gradually, yet the last deuterostome-protostome common ancestor already possessed an elaborate suite of genes associated with synaptic function, and critical for synaptic plasticity.
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16
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Rivi V, Benatti C, Lukowiak K, Colliva C, Alboni S, Tascedda F, Blom JM. What can we teach Lymnaea and what can Lymnaea teach us? Biol Rev Camb Philos Soc 2021; 96:1590-1602. [PMID: 33821539 PMCID: PMC9545797 DOI: 10.1111/brv.12716] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 01/20/2023]
Abstract
This review describes the advantages of adopting a molluscan complementary model, the freshwater snail Lymnaea stagnalis, to study the neural basis of learning and memory in appetitive and avoidance classical conditioning; as well as operant conditioning of its aerial respiratory and escape behaviour. We firstly explored 'what we can teach Lymnaea' by discussing a variety of sensitive, solid, easily reproducible and simple behavioural tests that have been used to uncover the memory abilities of this model system. Answering this question will allow us to open new frontiers in neuroscience and behavioural research to enhance our understanding of how the nervous system mediates learning and memory. In fact, from a translational perspective, Lymnaea and its nervous system can help to understand the neural transformation pathways from behavioural output to sensory coding in more complex systems like the mammalian brain. Moving on to the second question: 'what can Lymnaea teach us?', it is now known that Lymnaea shares important associative learning characteristics with vertebrates, including stimulus generalization, generalization of extinction and discriminative learning, opening the possibility to use snails as animal models for neuroscience translational research.
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Affiliation(s)
- Veronica Rivi
- Department of Biomedical, Metabolic and Neural SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
| | - Cristina Benatti
- Department of Life SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- Centre of Neuroscience and NeurotechnologyUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of MedicineUniversity of Calgary3330 Hospital Dr NWCalgaryABT2N 4N1Canada
| | - Chiara Colliva
- Department of Life SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- Centre of Neuroscience and NeurotechnologyUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
| | - Silvia Alboni
- Department of Life SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- Centre of Neuroscience and NeurotechnologyUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
| | - Fabio Tascedda
- Department of Life SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- Centre of Neuroscience and NeurotechnologyUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- CIB, Consorzio Interuniversitario BiotecnologieTriesteItaly
| | - Johanna M.C. Blom
- Department of Biomedical, Metabolic and Neural SciencesUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
- Centre of Neuroscience and NeurotechnologyUniversity of Modena and Reggio EmiliaVia CampiModena287‐41125Italy
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17
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Quantitative description of the interactions among kinase cascades underlying long-term plasticity of Aplysia sensory neurons. Sci Rep 2021; 11:14931. [PMID: 34294802 PMCID: PMC8298407 DOI: 10.1038/s41598-021-94393-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/01/2021] [Indexed: 11/09/2022] Open
Abstract
Kinases play critical roles in synaptic and neuronal changes involved in the formation of memory. However, significant gaps exist in the understanding of how interactions among kinase pathways contribute to the mechanistically distinct temporal domains of memory ranging from short-term memory to long-term memory (LTM). Activation of protein kinase A (PKA) and mitogen-activated protein kinase (MAPK)-ribosomal S6 kinase (RSK) pathways are critical for long-term enhancement of neuronal excitability (LTEE) and long-term synaptic facilitation (LTF), essential processes in memory formation. This study provides new insights into how these pathways contribute to the temporal domains of memory, using empirical and computational approaches. Empirical studies of Aplysia sensory neurons identified a positive feedforward loop in which the PKA and ERK pathways converge to regulate RSK, and a negative feedback loop in which p38 MAPK inhibits the activation of ERK and RSK. A computational model incorporated these findings to simulate the dynamics of kinase activity produced by different stimulus protocols and predict the critical roles of kinase interactions in the dynamics of these pathways. These findings may provide insights into the mechanisms underlying aberrant synaptic plasticity observed in genetic disorders such as RASopathies and Coffin-Lowry syndrome.
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Xu J, Casanave R, Guo S. Larval zebrafish display dynamic learning of aversive stimuli in a constant visual surrounding. ACTA ACUST UNITED AC 2021; 28:228-238. [PMID: 34131054 PMCID: PMC8212779 DOI: 10.1101/lm.053425.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/03/2021] [Indexed: 11/24/2022]
Abstract
Balancing exploration and anti-predation are fundamental to the fitness and survival of all animal species from early life stages. How these basic survival instincts drive learning remains poorly understood. Here, using a light/dark preference paradigm with well-controlled luminance history and constant visual surrounding in larval zebrafish, we analyzed intra- and intertrial dynamics for two behavioral components, dark avoidance and center avoidance. We uncover that larval zebrafish display short-term learning of dark avoidance with initial sensitization followed by habituation; they also exhibit long-term learning that is sensitive to trial interval length. We further show that such stereotyped learning patterns is stimulus-specific, as they are not observed for center avoidance. Finally, we demonstrate at individual levels that long-term learning is under homeostatic control. Together, our work has established a novel paradigm to understand learning, uncovered sequential sensitization and habituation, and demonstrated stimulus specificity, individuality, as well as dynamicity in learning.
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Affiliation(s)
- Jiale Xu
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisico, San Francisco, California 94158, USA
| | - Romelo Casanave
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisico, San Francisco, California 94158, USA
| | - Su Guo
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisico, San Francisco, California 94158, USA.,Program in Human Genetics, University of California at San Francisco, San Francisco, California 94158, USA.,Program in Biological Sciences, University of California at San Francisco, San Francisco, California 94158, USA
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19
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Gold AR, Glanzman DL. The central importance of nuclear mechanisms in the storage of memory. Biochem Biophys Res Commun 2021; 564:103-113. [PMID: 34020774 DOI: 10.1016/j.bbrc.2021.04.125] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/14/2022]
Abstract
The neurobiological nature of the memory trace (engram) remains controversial. The most widely accepted hypothesis at present is that long-term memory is stored as stable, learning-induced changes in synaptic connections. This hypothesis, the synaptic plasticity hypothesis of memory, is supported by extensive experimental data gathered from over 50 years of research. Nonetheless, there are important mnemonic phenomena that the synaptic plasticity hypothesis cannot, or cannot readily, account for. Furthermore, recent work indicates that epigenetic and genomic mechanisms play heretofore underappreciated roles in memory. Here, we critically assess the evidence that supports the synaptic plasticity hypothesis and discuss alternative non-synaptic, nuclear mechanisms of memory storage, including DNA methylation and retrotransposition. We argue that long-term encoding of memory is mediated by nuclear processes; synaptic plasticity, by contrast, represents a means of relatively temporary memory storage. In addition, we propose that memories are evaluated for their mnemonic significance during an initial period of synaptic storage; if assessed as sufficiently important, the memories then undergo nuclear encoding.
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Affiliation(s)
- Adam R Gold
- Behavioral Neuroscience Program, Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - David L Glanzman
- Department of Integrative Biology & Physiology, UCLA College, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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20
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Pang DKF, Elntib S. Strongly masked content retained in memory made accessible through repetition. Sci Rep 2021; 11:10284. [PMID: 33986370 PMCID: PMC8119432 DOI: 10.1038/s41598-021-89512-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/21/2021] [Indexed: 02/03/2023] Open
Abstract
A growing body of evidence indicates that information can be stored even in the absence of conscious awareness. Despite these findings, unconscious memory is still poorly understood with limited evidence for unconscious iconic memory storage. Here we show that strongly masked visual data can be stored and accumulate to elicit clear perception. We used a repetition method across a wide range of conditions (Experiment 1) and a more focused follow-up experiment with enhanced masking conditions (Experiment 2). Information was stored despite being masked, demonstrating that masking did not erase or overwrite memory traces but limited perception. We examined the temporal properties and found that stored information followed a gradual but rapid decay. Extraction of meaningful information was severely impaired after 300 ms, and most data was lost after 700 ms. Our findings are congruent with theories of consciousness that are based on an integration of subliminal information and support theoretical predictions based on the global workspace theory of consciousness, especially the existence of an implicit iconic memory buffer store.
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Affiliation(s)
- Damian K. F. Pang
- grid.10025.360000 0004 1936 8470Department of Psychological Sciences, Institute of Psychology, Health and Society, University of Liverpool, Liverpool, L69 3BX UK ,grid.25879.310000 0004 1936 8972School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Stamatis Elntib
- grid.10025.360000 0004 1936 8470Department of Psychological Sciences, Institute of Psychology, Health and Society, University of Liverpool, Liverpool, L69 3BX UK
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21
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Abstract
Invertebrate animals comprise more than 95% of the animal kingdom's species and approximately 40 separate phyla. Yet, invertebrates are an artificial taxon, in which all members simply possess a single negative trait: they lack a vertebral column (backbone). In fact, some invertebrates are more closely related to vertebrates than to their "fellow" invertebrates. For the purpose of this veterinary article, we have elected to review a handful of important groups: Coelenterates, Gastropods, Cephalopods, Chelicerates, Crustaceans, Insects, and Echinoderms. We have primarily included behaviors that may have an impact on clinical case outcome, or be of interest to the veterinary clinician.
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Affiliation(s)
- Gregory A Lewbart
- Department of Clinical Sciences, NC State University College of Veterinary Medicine, 1060 William Moore Drive, Raleigh, NC 27607, USA.
| | - Laurie Bergmann
- NorthStar VETS, 315 Robbinsville-Allentown Road, Robbinsville, NJ 08691, USA
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22
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Induction of Short-Term Sensitization by an Aversive Chemical Stimulus in Zebrafish Larvae. eNeuro 2020; 7:ENEURO.0336-19.2020. [PMID: 33004417 PMCID: PMC7729299 DOI: 10.1523/eneuro.0336-19.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 12/26/2022] Open
Abstract
Larval zebrafish possess a number of molecular and genetic advantages for rigorous biological analyses of learning and memory. These advantages have motivated the search for novel forms of memory in these animals that can be exploited for understanding the cellular and molecular bases of vertebrate memory formation and consolidation. Here, we report a new form of behavioral sensitization in zebrafish larvae that is elicited by an aversive chemical stimulus [allyl isothiocyanate (AITC)] and that persists for ≥30 min. This form of sensitization is expressed as enhanced locomotion and thigmotaxis, as well as elevated heart rate. To characterize the neural basis of this nonassociative memory, we used transgenic zebrafish expressing the fluorescent calcium indicator GCaMP6 (Chen et al., 2013); because of the transparency of larval zebrafish, we could optically monitor neural activity in the brain of intact transgenic zebrafish before and after the induction of sensitization. We found a distinct brain area, previously linked to locomotion, that exhibited persistently enhanced neural activity following washout of AITC; this enhanced neural activity correlated with the behavioral sensitization. These results establish a novel form of memory in larval zebrafish and begin to unravel the neural basis of this memory.
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23
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Multiple Local Synaptic Modifications at Specific Sensorimotor Connections after Learning Are Associated with Behavioral Adaptations That Are Components of a Global Response Change. J Neurosci 2020; 40:4363-4371. [PMID: 32366723 DOI: 10.1523/jneurosci.2647-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/21/2022] Open
Abstract
Learning causes local changes in synaptic connectivity and coordinated, global changes affecting many aspects of behavior. How do local synaptic changes produce global behavioral changes? In the hermaphroditic mollusc Aplysia, after learning that food is inedible, memory is expressed as bias to reject a food and to reduce responses to that food. We now show that memory is also expressed as an increased bias to reject even a nonfood object. The increased bias to rejection is partially explained by changes in synaptic connections from primary mechanoafferents to five follower neurons with well defined roles in producing different feeding behaviors. Previously, these mechanoafferents had been shown to play a role in memory consolidation. Connectivity changes differed for each follower neuron: the probability that cells were connected changed; excitation changed to inhibition and vice versa; and connection amplitude changed. Thus, multiple neural changes at different sites underlie specific aspects of a coordinated behavioral change. Changes in the connectivity between mechanoafferents and their followers cannot account for all of the behavioral changes expressed after learning, indicating that additional synaptic sites are also changed. Access to the circuit controlling feeding can help determine the logic and cellular mechanisms by which multiple local synaptic changes produce an integrated, global change in behavior.SIGNIFICANCE STATEMENT How do local changes in synapses affect global behavior? Studies on invertebrate preparations usually examine synaptic changes at specific neural sites, producing a specific behavioral change. However, memory may be expressed by multiple behavioral changes. We report that a change in behavior after learning in Aplysia is accomplished, in part, by regulating connections between mechanoafferents and their synaptic followers. For some followers, the connection probabilities change; for others, the connection signs are reversed; in others, the connection strength is modified. Thus, learning produces changes in connectivity at multiple sites, via multiple synaptic mechanisms that are consistent with the observed behavioral change.
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24
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Specificity of synapse formation in Aplysia: paracrine and autocrine signaling regulates bidirectional molecular interactions between sensory and non-target motor neurons. Sci Rep 2020; 10:5222. [PMID: 32251363 PMCID: PMC7089980 DOI: 10.1038/s41598-020-62099-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/02/2020] [Indexed: 12/01/2022] Open
Abstract
The formation of appropriate neural connections during development is critical for the proper wiring and functioning of the brain. Although considerable research suggests that the specificity of synapse formation is supported by complex intercellular signaling between potential presynaptic and postsynaptic partners, the extracellular factors and the intracellular signal transduction pathways engaged in this process remain largely unknown. Using the sensory-motor neural circuit that contributes to learning in defensive withdrawal reflexes in Aplysia californica, we investigated the molecular processes governing the interactions between sensory neurons and both target and non-target motor neurons during synapse formation in culture. We found that evolutionarily-conserved intercellular and intracellular signaling mechanisms critical for learning-related plasticity are also engaged during synaptogenesis in this in vitro model system. Our results reveal a surprising bidirectional regulation of molecular signaling between sensory neurons and non-target motor neurons. This regulation is mediated by signaling via both paracrine and autocrine diffusible factors that induce differential effects on transcription and on protein expression/activation in sensory neurons and in target and non-target motor neurons. Collectively, our data reveal novel molecular mechanisms that could underlie the repression of inappropriate synapse formation, and suggest mechanistic similarities between developmental and learning-related plasticity.
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25
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Zhao B, Xiao M, Shen D, Zhou YN. Heterogeneous stimuli induced nonassociative learning behavior in ZnO nanowire memristor. NANOTECHNOLOGY 2020; 31:125201. [PMID: 31801120 DOI: 10.1088/1361-6528/ab5ead] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nonassociative learning is a biologically essential and evolutionarily adaptive behavior in organisms. The bionic simulation of nonassociative learning based on electronic devices is essential to the neuromorphic computing. In this work, nonassociative learning is mimicked by a ZnO nanowire memristor without any other peripheral control circuit. The memristor demonstrates habituation and sensitization behaviors at the electrical and optical stimuli. Typical network-level parametric characteristics of habituation in neuroscience are realized in the memristor. When the heterogeneous stimuli are applied coincidentally, sensitization pulse could be identified by the exceptional response current. The results show that the natural selection rules could be simulated by the current single memristor. A possible mechanism based on the trapping states and adsorption of oxygen at the interface of Au/ZnO is proposed. The implementation of nonassociative learning in a single memristor device paves the way for building neuromorphic systems by simple electronic devices.
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Affiliation(s)
- Bo Zhao
- Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, People's Republic of China. Centre for Advanced Materials Joining, Department of Mechanics and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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26
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Alexandrescu A, Carew TJ. Postsynaptic effects of Aplysia cysteine-rich neurotrophic factor in the induction of activity-dependent long-term facilitation in Aplysia californica. ACTA ACUST UNITED AC 2020; 27:124-129. [PMID: 32179654 PMCID: PMC7079570 DOI: 10.1101/lm.051011.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/18/2019] [Indexed: 12/23/2022]
Abstract
The spatial and temporal coordination of growth factor signaling is critical for both presynaptic and postsynaptic plasticity underlying long-term memory formation. We investigated the spatiotemporal dynamics of Aplysia cysteine-rich neurotrophic factor (ApCRNF) signaling during the induction of activity-dependent long-term facilitation (AD-LTF) at sensory-to-motor neuron synapses that mediate defensive reflexes in Aplysia We found that ApCRNF signaling is required for the induction of AD-LTF, and for training-induced early protein kinase activation and late forms of gene expression, exclusively in postsynaptic neurons. These results support the view that ApCRNF is critically involved in AD-LTF at least in part through postsynaptic mechanisms.
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Affiliation(s)
- Anamaria Alexandrescu
- Neuroscience Institute, New York University School of Medicine, New York, New York 10016, USA
| | - Thomas J Carew
- Center for Neural Science, New York University, New York, New York 10003, USA
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27
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Chatterji R, Khoury S, Salas E, Wainwright ML, Mozzachiodi R. Critical role of protein kinase G in the long-term balance between defensive and appetitive behaviors induced by aversive stimuli in Aplysia. Behav Brain Res 2020; 383:112504. [PMID: 31981653 DOI: 10.1016/j.bbr.2020.112504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 11/25/2022]
Abstract
This study investigated the signaling cascades involved in the long-term storage of the balance between defensive and appetitive behaviors observed when the mollusk Aplysia is exposed to aversive experience. In Aplysia, repeated trials of aversive stimuli induce concurrent sensitization of defensive withdrawal reflexes and suppression of feeding for at least 24 h. This long-term storage of the balance between withdrawal reflexes and feeding is sustained, at least in part, by increased excitability of the tail sensory neurons (SNs) controlling the withdrawal reflexes, and by decreased excitability of feeding decision-making neuron B51. Nitric oxide (NO) is required for the induction of both long-term sensitization and feeding suppression. At the cellular level, NO is also required for long-term decreased B51 excitability but not for long-term increased SN excitability. Here, we characterized the signaling cascade downstream of NO contributing to the long-term storage of the balance between withdrawal reflexes and feeding. We found protein kinase G (PKG) necessary for both long-term sensitization and feeding suppression, indicating that a NO-PKG cascade governs the long-term storage of the balance between defensive and appetitive responses in Aplysia. The role of PKG on feeding suppression was paralleled at the cellular level where a cGMP-PKG pathway was required for long-term decreased B51 excitability. In the defensive circuit, the cGMP-PKG pathway was not necessary for long-term increased SN excitability, suggesting that other cellular correlates of long-term sensitization might depend on the GMP-PKG cascade to sustain the behavioral change.
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Affiliation(s)
- Ruma Chatterji
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA; Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio 45221, USA
| | - Sarah Khoury
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA; Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
| | - Emanuel Salas
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA.
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28
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Lewis V, Laberge F, Heyland A. Temporal Profile of Brain Gene Expression After Prey Catching Conditioning in an Anuran Amphibian. Front Neurosci 2020; 13:1407. [PMID: 31992968 PMCID: PMC6971186 DOI: 10.3389/fnins.2019.01407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/12/2019] [Indexed: 12/19/2022] Open
Abstract
A key goal in modern neurobiology is to understand the mechanisms underlying learning and memory. To that end, it is essential to identify the patterns of gene expression and the temporal sequence of molecular events associated with learning and memory processes. It is also important to ascertain if and how these molecular events vary between organisms. In vertebrates, learning and memory processes are characterized by distinct phases of molecular activity involving gene transcription, structural change, and long-term maintenance of such structural change in the nervous system. Utilizing next generation sequencing techniques, we profiled the temporal expression patterns of genes in the brain of the fire-bellied toad Bombina orientalis after prey catching conditioning. The fire-bellied toad is a basal tetrapod whose neural architecture and molecular pathways may help us understand the ancestral state of learning and memory mechanisms in tetrapods. Differential gene expression following conditioning revealed activity in molecular pathways related to immediate early genes (IEG), cytoskeletal modification, axon guidance activity, and apoptotic processes. Conditioning induced early IEG activity coinciding with transcriptional activity and neuron structural modification, followed by axon guidance and cell adhesion activity, and late neuronal pruning. While some of these gene expression patterns are similar to those found in mammals submitted to conditioning, some interesting divergent expression profiles were seen, and differential expression of some well-known learning-related mammalian genes is missing altogether. These results highlight the importance of using a comparative approach in the study of the mechanisms of leaning and memory and provide molecular resources for a novel vertebrate model in the relatively poorly studied Amphibia.
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Affiliation(s)
- Vern Lewis
- Integrative Biology, University of Guelph, Guelph, ON, Canada
| | | | - Andreas Heyland
- Integrative Biology, University of Guelph, Guelph, ON, Canada
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29
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Farruggella J, Acebo J, Lloyd L, Wainwright ML, Mozzachiodi R. Role of nitric oxide in the induction of the behavioral and cellular changes produced by a common aversive stimulus in Aplysia. Behav Brain Res 2018; 360:341-353. [PMID: 30528940 DOI: 10.1016/j.bbr.2018.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 10/27/2022]
Abstract
Although it is well documented that exposure to aversive stimuli induces modulation of neural circuits and subsequent behavioral changes, the means by which an aversive stimulus concomitantly alters behaviors of different natures (e.g., defensive and appetitive) remains unclear. Here, we addressed this issue by using the learning-induced concurrent modulation of defensive and appetitive behaviors that occurs when the mollusk Aplysia is exposed to aversive stimuli. In Aplysia, aversive stimuli concomitantly enhance withdrawal reflexes (i.e., sensitization) and suppress feeding. Sensitization and feeding suppression, which are expressed in the short term and long term, depending on the training protocol, are accompanied by increased excitability of the tail sensory neurons (TSNs) controlling the withdrawal reflexes, and by decreased excitability of feeding decision-making neuron B51, respectively. Serotonin (5-HT) has been shown to mediate sensitization, but not feeding suppression. In this study, we examined which other neurotransmitter might be responsible for feeding suppression and its underlying cellular changes. Our results indicate that nitric oxide (NO) contributes to both short-term and long-term feeding suppression, as well as to the underlying decreased B51 excitability. NO was also necessary for the induction of long-term sensitization and for the expression of short-term increased TSN excitability in vitro, revealing a previously undocumented interaction between 5-HT and NO signaling cascades in sensitization. Overall, these results revealed a scenario in which multiple modulators contribute to the widespread changes induced by sensitizing stimuli in Aplysia.
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Affiliation(s)
- Jesse Farruggella
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX, 78412, USA
| | - Jonathan Acebo
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX, 78412, USA
| | - Leah Lloyd
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX, 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX, 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX, 78412, USA.
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30
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Autocrine signaling by an Aplysia neurotrophin forms a presynaptic positive feedback loop. Proc Natl Acad Sci U S A 2018; 115:E11168-E11177. [PMID: 30397154 DOI: 10.1073/pnas.1810649115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Whereas short-term plasticity is often initiated on one side of the synapse, long-term plasticity involves coordinated changes on both sides, implying extracellular signaling. We have investigated the possible signaling role of an Aplysia neurotrophin (ApNT) in facilitation induced by serotonin (5HT) at sensory-to-motor neuron synapses in culture. ApNT is an ortholog of mammalian BDNF, which has been reported to act as either an anterograde, retrograde, or autocrine signal, so that its pre- and postsynaptic sources and targets remain unclear. We now report that ApNT acts as a presynaptic autocrine signal that forms part of a positive feedback loop with ApTrk and PKA. That loop stimulates spontaneous transmitter release, which recruits postsynaptic mechanisms, and presynaptic protein synthesis during the transition from short- to intermediate-term facilitation and may also initiate gene regulation to trigger the transition to long-term facilitation. These results suggest that a presynaptic ApNT feedback loop plays several key roles during consolidation of learning-related synaptic plasticity.
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31
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Walters ET. Nociceptive Biology of Molluscs and Arthropods: Evolutionary Clues About Functions and Mechanisms Potentially Related to Pain. Front Physiol 2018; 9:1049. [PMID: 30123137 PMCID: PMC6085516 DOI: 10.3389/fphys.2018.01049] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/16/2018] [Indexed: 01/15/2023] Open
Abstract
Important insights into the selection pressures and core molecular modules contributing to the evolution of pain-related processes have come from studies of nociceptive systems in several molluscan and arthropod species. These phyla, and the chordates that include humans, last shared a common ancestor approximately 550 million years ago. Since then, animals in these phyla have continued to be subject to traumatic injury, often from predators, which has led to similar adaptive behaviors (e.g., withdrawal, escape, recuperative behavior) and physiological responses to injury in each group. Comparisons across these taxa provide clues about the contributions of convergent evolution and of conservation of ancient adaptive mechanisms to general nociceptive and pain-related functions. Primary nociceptors have been investigated extensively in a few molluscan and arthropod species, with studies of long-lasting nociceptive sensitization in the gastropod, Aplysia, and the insect, Drosophila, being especially fruitful. In Aplysia, nociceptive sensitization has been investigated as a model for aversive memory and for hyperalgesia. Neuromodulator-induced, activity-dependent, and axotomy-induced plasticity mechanisms have been defined in synapses, cell bodies, and axons of Aplysia primary nociceptors. Studies of nociceptive sensitization in Drosophila larvae have revealed numerous molecular contributors in primary nociceptors and interacting cells. Interestingly, molecular contributors examined thus far in Aplysia and Drosophila are largely different, but both sets overlap extensively with those in mammalian pain-related pathways. In contrast to results from Aplysia and Drosophila, nociceptive sensitization examined in moth larvae (Manduca) disclosed central hyperactivity but no obvious peripheral sensitization of nociceptive responses. Squid (Doryteuthis) show injury-induced sensitization manifested as behavioral hypersensitivity to tactile and especially visual stimuli, and as hypersensitivity and spontaneous activity in nociceptor terminals. Temporary blockade of nociceptor activity during injury subsequently increased mortality when injured squid were exposed to fish predators, providing the first demonstration in any animal of the adaptiveness of nociceptive sensitization. Immediate responses to noxious stimulation and nociceptive sensitization have also been examined behaviorally and physiologically in a snail (Helix), octopus (Adopus), crayfish (Astacus), hermit crab (Pagurus), and shore crab (Hemigrapsus). Molluscs and arthropods have systems that suppress nociceptive responses, but whether opioid systems play antinociceptive roles in these phyla is uncertain.
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Affiliation(s)
- Edgar T Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
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32
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Goldner A, Farruggella J, Wainwright ML, Mozzachiodi R. cGMP mediates short- and long-term modulation of excitability in a decision-making neuron in Aplysia. Neurosci Lett 2018; 683:111-118. [PMID: 29960055 DOI: 10.1016/j.neulet.2018.06.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/17/2018] [Accepted: 06/22/2018] [Indexed: 01/11/2023]
Abstract
In elementary neural circuits, changes in excitability can have a strong impact in the expression of a given behavior. One example is provided by B51, a neuron with decision-making properties in the feeding neural circuit of the mollusk Aplysia. The excitability of B51 is bidirectionally modulated by external and internal stimuli in a manner that is consistent with the corresponding induced changes in feeding behavior. For example, in operant reward learning, which up-regulates feeding, B51 excitability is increased via a cAMP-dependent mechanism. Conversely, following training protocols with aversive stimuli, which down-regulate feeding, B51 excitability is decreased. In this study, we tested the hypothesis that B51 decreased excitability may be mediated by another cyclic nucleotide, cGMP. Our results revealed that iontophoretic injection of cGMP was capable of inducing both short-term (45 min) and long-term (24 h) reduction of B51 excitability. We next investigated which biochemical trigger could increase cGMP cytosolic levels. The neurotransmitter nitric oxide was found to decrease B51 excitability through the activation of the soluble guanylyl cyclase. These findings indicate that a cGMP-dependent pathway modulates B51 excitability in a manner opposite of cAMP, indicating that distinct cyclic-nucleotide pathways bidirectionally regulate the excitability of a decision-making neuron.
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Affiliation(s)
- Amanda Goldner
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Jesse Farruggella
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA.
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33
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RNA from Trained Aplysia Can Induce an Epigenetic Engram for Long-Term Sensitization in Untrained Aplysia. eNeuro 2018; 5:eN-NWR-0038-18. [PMID: 29789810 PMCID: PMC5962046 DOI: 10.1523/eneuro.0038-18.2018] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/25/2018] [Accepted: 04/27/2018] [Indexed: 02/07/2023] Open
Abstract
The precise nature of the engram, the physical substrate of memory, remains uncertain. Here, it is reported that RNA extracted from the central nervous system of Aplysia given long-term sensitization (LTS) training induced sensitization when injected into untrained animals; furthermore, the RNA-induced sensitization, like training-induced sensitization, required DNA methylation. In cellular experiments, treatment with RNA extracted from trained animals was found to increase excitability in sensory neurons, but not in motor neurons, dissociated from naïve animals. Thus, the behavioral, and a subset of the cellular, modifications characteristic of a form of nonassociative long-term memory (LTM) in Aplysia can be transferred by RNA. These results indicate that RNA is sufficient to generate an engram for LTS in Aplysia and are consistent with the hypothesis that RNA-induced epigenetic changes underlie memory storage in Aplysia.
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34
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Leod KAM, Seas A, Wainwright ML, Mozzachiodi R. Effects of internal and external factors on the budgeting between defensive and non-defensive responses in Aplysia. Behav Brain Res 2018; 349:177-185. [PMID: 29704600 DOI: 10.1016/j.bbr.2018.04.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/23/2018] [Accepted: 04/13/2018] [Indexed: 10/17/2022]
Abstract
Following exposure to aversive stimuli, organisms budget their behaviors by augmenting defensive responses and reducing/suppressing non-defensive behaviors. This budgeting process must be flexible to accommodate modifications in the animal's internal and/or external state that require the normal balance between defensive and non-defensive behaviors to be adjusted. When exposed to aversive stimuli, the mollusk Aplysia budgets its behaviors by concurrently enhancing defensive withdrawal reflexes (an elementary form of learning known as sensitization) and suppressing feeding. Sensitization and feeding suppression are consistently co-expressed following different training protocols and share common temporal domains, suggesting that they are interlocked. In this study, we attempted to uncouple the co-expression of sensitization and feeding suppression using: 1) manipulation of the animal's motivational state through prolonged food deprivation and 2) extended training with aversive stimuli that induces sensitization lasting for weeks. Both manipulations uncoupled the co-expression of the above behavioral changes. Prolonged food deprivation prevented the expression of sensitization, but not of feeding suppression. Following the extended training, sensitization and feeding suppression were co-expressed only for a limited time (i.e., 24 h), after which feeding returned to baseline levels as sensitization persisted for up to seven days. These findings indicate that sensitization and feeding suppression are not interlocked and that their co-expression can be uncoupled by internal (prolonged food deprivation) and external (extended aversive training) factors. The different strategies, by which the co-expression of sensitization and feeding suppression was altered, provide an example of how budgeting strategies triggered by an identical aversive experience can vary depending on the state of the organism.
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Affiliation(s)
- Kaitlyn A Mac Leod
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Alexandra Seas
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA.
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Seehafer K, Brophy S, Tom SR, Crook RJ. Ontogenetic and Experience-Dependent Changes in Defensive Behavior in Captive-Bred Hawaiian Bobtail Squid, Euprymna scolopes. Front Physiol 2018; 9:299. [PMID: 29651249 PMCID: PMC5884957 DOI: 10.3389/fphys.2018.00299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 03/13/2018] [Indexed: 11/25/2022] Open
Abstract
Cephalopod molluscs are known for their extensive behavioral repertoire and their impressive learning abilities. Their primary defensive behaviors, such as camouflage, have received detailed study, but knowledge is limited to intensive study of relatively few species. A considerable challenge facing cephalopod research is the need to establish new models that can be captive bred, are tractable for range of different experimental procedures, and that will address broad questions in biological research. The Hawaiian Bobtail Squid (Euprymna scolopes) is a small, tropical cephalopod that has a long history of research in the field of microbial symbiosis, but offers great promise as a novel behavioral and neurobiological model. It can be bred in the laboratory through multiple generations, one of the few species of cephalopod that can meet this requirement (which is incorporated in regulations such as EU directive 2010/63/EU). Additionally, laboratory culture makes E. scolopes an ideal model for studying ontogeny- and experience-dependent behaviors. In this study, we show that captive bred juvenile and adult E. scolopes produce robust, repeatable defensive behaviors when placed in an exposed environment and presented with a visual threat. Further, adult and juvenile squid employ different innate defensive behaviors when presented with a size-matched model predator. When a 10-min training procedure was repeated over three consecutive days, defensive behaviors habituated in juvenile squid for at least 5 days after training, but memory did not appear to persist for 14 days. In contrast, adult squid did not show any evidence of long-term habituation memory. Thus we conclude that this species produces a range of quantifiable, modifiable behaviors even in a laboratory environment where ecologically-relevant, complex behavioral sequences may not reliably occur. We suggest that the lack of long-term memory in adult squid may be related to their less escalated initial response to the mimic, and thus indicates less motivation to retain memory and not necessary inability to form memory. This is the first demonstration of age-related differences in defensive behaviors in Euprymna, and the first record of habituation in this experimentally tractable genus of squid.
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Affiliation(s)
- Kia Seehafer
- Department of Biology, Sacramento State University, Sacramento, CA, United States
| | - Samantha Brophy
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Sara R Tom
- Department of Biology, San Francisco State University, San Francisco, CA, United States
| | - Robyn J Crook
- Department of Biology, San Francisco State University, San Francisco, CA, United States
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Abstract
Members of the phylum Mollusca demonstrate the animal kingdom's tremendous diversity of body morphology, size and complexity of the nervous system, as well as diversity of behavioral repertoires, ranging from very simple to highly flexible. Molluscs include Solenogastres, with their worm-like bodies and behavior (see phylogenetic tree; Figure 1); Bivalvia (mussels and clams), protected by shells and practically immobile; and the cephalopods, such as the octopus, cuttlefish and squid. The latter are strange-looking animals with nervous systems comprising up to half a billion neurons, which mediate the complex behaviors that characterize these freely moving, highly visual predators. Molluscs are undoubtedly special - their extraordinary evolutionary advance somehow managed to sidestep the acquisition of the rigid skeleton that appears essential to the evolution of other 'successful' phyla: the exoskeleton in ecdysozoan invertebrates and the internal skeleton in Deuterostomia, including vertebrates.
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Affiliation(s)
- Binyamin Hochner
- Department of Neurobiology, Silberman Institute of Life Sciences, Hebrew University, Jerusalem, Israel.
| | - David L Glanzman
- Department of Integrative Biology and Physiology, University of California Los Angeles, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, USA.
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Weisz HA, Wainwright ML, Mozzachiodi R. A novel in vitro analog expressing learning-induced cellular correlates in distinct neural circuits. ACTA ACUST UNITED AC 2017; 24:331-340. [PMID: 28716953 PMCID: PMC5516688 DOI: 10.1101/lm.045229.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 05/12/2017] [Indexed: 01/29/2023]
Abstract
When presented with noxious stimuli, Aplysia exhibits concurrent sensitization of defensive responses, such as the tail-induced siphon withdrawal reflex (TSWR) and suppression of feeding. At the cellular level, sensitization of the TSWR is accompanied by an increase in the excitability of the tail sensory neurons (TSNs) that elicit the reflex, whereas feeding suppression is accompanied by decreased excitability of B51, a decision-making neuron in the feeding neural circuit. The goal of this study was to develop an in vitro analog coexpressing the above cellular correlates. We used a reduced preparation consisting of buccal, cerebral, and pleural-pedal ganglia, which contain the neural circuits controlling feeding and the TSWR, respectively. Sensitizing stimuli were delivered in vitro by electrical stimulation of afferent nerves. When trained with sensitizing stimuli, the in vitro analog expressed concomitant increased excitability in TSNs and decreased excitability in B51, which are consistent with the occurrence of sensitization and feeding suppression induced by in vivo training. This in vitro analog expressed both short-term (15 min) and long-term (24 h) excitability changes in TSNs and B51, depending on the amount of training administered. Finally, in vitro application of serotonin increased TSN excitability without altering B51 excitability, mirroring the in vivo application of the monoamine that induces sensitization, but not feeding suppression.
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Affiliation(s)
- Harris A Weisz
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
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Hernandez JS, Wainwright ML, Mozzachiodi R. Long-term sensitization training in Aplysia decreases the excitability of a decision-making neuron through a sodium-dependent mechanism. ACTA ACUST UNITED AC 2017; 24:257-261. [PMID: 28507035 PMCID: PMC5435880 DOI: 10.1101/lm.044883.116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 03/31/2017] [Indexed: 11/24/2022]
Abstract
In Aplysia, long-term sensitization (LTS) occurs concurrently with a suppression of feeding. At the cellular level, the suppression of feeding is accompanied by decreased excitability of decision-making neuron B51. We examined the contribution of voltage-gated Na+ and K+ channels to B51 decreased excitability. In a pharmacologically isolated Na+ channels environment, LTS training significantly increased B51 firing threshold, compared with untrained controls. Conversely, in a pharmacologically isolated K+ channels environment, no differences were observed between trained and untrained animals in either amplitude or area of B51 K+-dependent depolarizations. These findings suggest that Na+ channels contribute to the decrease in B51 excitability induced by LTS training.
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Affiliation(s)
- John S Hernandez
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
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Lyons LC, Gardner JS, Gandour CE, Krishnan HC. Role of proteasome-dependent protein degradation in long-term operant memory in Aplysia. ACTA ACUST UNITED AC 2016; 24:59-64. [PMID: 27980077 PMCID: PMC5159658 DOI: 10.1101/lm.043794.116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 10/24/2016] [Indexed: 01/26/2023]
Abstract
We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in Aplysia using an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through inhibition of protein synthesis using either anisomycin or rapamycin in conjunction with proteasome inhibition permitted the formation of robust 24 h LTM. Our studies suggest a primary role for proteasomal activity in facilitation of gene transcription for LTM and raise the possibility that synaptic mechanisms are sufficient to sustain 24 h memory.
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Affiliation(s)
- Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4295, USA
| | - Jacob S Gardner
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4295, USA
| | - Catherine E Gandour
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4295, USA
| | - Harini C Krishnan
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4295, USA
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Yang X, Fang Y, Yu Z, Wang Z, Zhang T, Yin M, Lin M, Yang Y, Cai Y, Huang R. Nonassociative learning implementation by a single memristor-based multi-terminal synaptic device. NANOSCALE 2016; 8:18897-18904. [PMID: 27714050 DOI: 10.1039/c6nr04142f] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Animals' survival is dependent on their abilities to adapt to the changing environment by adjusting their behaviours, which is related to the ubiquitous learning behaviour, nonassociative learning. Thus mimicking the indispensable learning behaviour in organisms based on electronic devices is vital to better achieve artificial neural networks and neuromorphic computing. Here a three terminal device consisting of an oxide-based memristor and a NMOS transistor is proposed. The memristor with gradual conductance tuning inherently functions as the synapse between sensor neurons and motor neurons and presents adjustable synaptic plasticity, while the NMOS transistor attached to the memristor is utilized to mimic the modulatory effect of the neuromodulator released by inter neurons. Such a memristor-based multi-terminal device allows the practical implementation of significant nonassociative learning based on a single electronic device. In this study, the experience-induced modification behaviour, both habituation and sensitization, was successfully achieved. The dependence of the nonassociative behavioural response on the strength and interval of presented stimuli was also discussed. The implementation of nonassociative learning offers feasible and experimental advantages for further study on neuromorphic systems based on electronic devices.
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Affiliation(s)
- Xue Yang
- Institute of Microelectronics, Peking University, 100871, Beijing, China
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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: 3.0] [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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Wolfe KD, Wainwright ML, Smee DL, Mozzachiodi R. Eat or be eaten? Modifications of Aplysia californica feeding behaviour in response to natural aversive stimuli. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.07.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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43
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Persistent Associative Plasticity at an Identified Synapse Underlying Classical Conditioning Becomes Labile with Short-Term Homosynaptic Activation. J Neurosci 2016; 35:16159-70. [PMID: 26658867 DOI: 10.1523/jneurosci.2034-15.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Synapses express different forms of plasticity that contribute to different forms of memory, and both memory and plasticity can become labile after reactivation. We previously reported that a persistent form of nonassociative long-term facilitation (PNA-LTF) of the sensorimotor synapses in Aplysia californica, a cellular analog of long-term sensitization, became labile with short-term heterosynaptic reactivation and reversed when the reactivation was followed by incubation with the protein synthesis inhibitor rapamycin. Here we examined the reciprocal impact of different forms of short-term plasticity (reactivations) on a persistent form of associative long-term facilitation (PA-LTF), a cellular analog of classical conditioning, which was expressed at Aplysia sensorimotor synapses when a tetanic stimulation of the sensory neurons was paired with a brief application of serotonin on 2 consecutive days. The expression of short-term homosynaptic plasticity [post-tetanic potentiation or homosynaptic depression (HSD)], or short-term heterosynaptic plasticity [serotonin-induced facilitation or neuropeptide Phe-Met-Arg-Phe-NH2 (FMRFa)-induced depression], at synapses expressing PA-LTF did not affect the maintenance of PA-LTF. The kinetics of HSD was attenuated at synapses expressing PA-LTF, which required activation of protein kinase C (PKC). Both PA-LTF and the attenuated kinetics of HSD were reversed by either a transient blockade of PKC activity or a homosynaptic, but not heterosynaptic, reactivation when paired with rapamycin. These results indicate that two different forms of persistent synaptic plasticity, PA-LTF and PNA-LTF, expressed at the same synapse become labile when reactivated by different stimuli. SIGNIFICANCE STATEMENT Activity-dependent changes in neural circuits mediate long-term memories. Some forms of long-term memories become labile and can be reversed with specific types of reactivations, but the mechanism is complex. At the cellular level, reactivations that induce a reversal of memory must evoke changes in neural circuits underlying the memory. What types of reactivations induce a labile state at neural connections that lead to reversal of different types of memory? We find that a critical neural connection in Aplysia, which is modified with different stimuli that mediate different types of memory, becomes labile with different types of reactivations. These results provide insights for developing strategies in alleviating maladaptive memories accompanying anxiety disorders.
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Mayford M, Reijmers L. Exploring Memory Representations with Activity-Based Genetics. Cold Spring Harb Perspect Biol 2015; 8:a021832. [PMID: 26684182 DOI: 10.1101/cshperspect.a021832] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The brain is thought to represent specific memories through the activity of sparse and distributed neural ensembles. In this review, we examine the use of immediate early genes (IEGs), genes that are induced by neural activity, to specifically identify and genetically modify neurons activated naturally by environmental experience. Recent studies using this approach have identified cellular and molecular changes specific to neurons activated during learning relative to their inactive neighbors. By using opto- and chemogenetic regulators of neural activity, the neurons naturally recruited during learning can be artificially reactivated to directly test their role in coding external information. In contextual fear conditioning, artificial reactivation of learning-induced neural ensembles in the hippocampus or neocortex can substitute for the context itself. That is, artificial stimulation of these neurons can apparently cause the animals to "think" they are in the context. This represents a powerful approach to testing the principles by which the brain codes for the external world and how these circuits are modified with learning.
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Affiliation(s)
- Mark Mayford
- Molecular and Cellular Neurosciences Department, The Scripps Research Institute, La Jolla, California 92037
| | - Leon Reijmers
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts 02111
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Ben-Yakov A, Dudai Y, Mayford MR. Memory Retrieval in Mice and Men. Cold Spring Harb Perspect Biol 2015; 7:cshperspect.a021790. [PMID: 26438596 DOI: 10.1101/cshperspect.a021790] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Retrieval, the use of learned information, was until recently mostly terra incognita in the neurobiology of memory, owing to shortage of research methods with the spatiotemporal resolution required to identify and dissect fast reactivation or reconstruction of complex memories in the mammalian brain. The development of novel paradigms, model systems, and new tools in molecular genetics, electrophysiology, optogenetics, in situ microscopy, and functional imaging, have contributed markedly in recent years to our ability to investigate brain mechanisms of retrieval. We review selected developments in the study of explicit retrieval in the rodent and human brain. The picture that emerges is that retrieval involves coordinated fast interplay of sparse and distributed corticohippocampal and neocortical networks that may permit permutational binding of representational elements to yield specific representations. These representations are driven largely by the activity patterns shaped during encoding, but are malleable, subject to the influence of time and interaction of the existing memory with novel information.
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Affiliation(s)
- Aya Ben-Yakov
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yadin Dudai
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel Center for Neural Science, New York University, New York, New York 10003
| | - Mark R Mayford
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, California 92037
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46
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Burhans LB, Smith-Bell CA, Schreurs BG. Effects of extinction treatments on the reduction of conditioned responding and conditioned hyperarousal in a rabbit model of posttraumatic stress disorder (PTSD). Behav Neurosci 2015; 129:611-20. [PMID: 26348715 PMCID: PMC4667790 DOI: 10.1037/bne0000092] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have previously characterized a model of posttraumatic stress disorder (PTSD), based on classical conditioning of the rabbit nictitating membrane response (NMR), that focuses on 2 key PTSD-like features: conditioned responses to trauma-associated cues and hyperarousal. In addition to the development of conditioned NMRs (CRs) to a tone conditioned stimulus (CS) associated with a periorbital shock unconditioned stimulus (US), we have observed that rabbits also exhibit a conditioning-specific reflex modification (CRM) of the NMR that manifests as an exaggerated and more complex reflexive NMR to presentations of the US by itself, particularly to intensities that elicited little response prior to conditioning. Previous work has demonstrated that unpaired presentations of the CS and US are successful at extinguishing CRs and CRM simultaneously, even when a significantly weakened version of the US is utilized. In the current study, additional extinction treatments were tested, including continued pairings of the CS with a weakened US and exposure to the training context alone, and these treatments were contrasted with the effects of unpaired extinction with a weakened US and remaining in home cages with no further treatment. Results showed that continued pairings only slightly decreased CRs and CRM, while context exposure had no effect on CRs and marginal effects on reducing CRM. Unpaired extinction was still the most effective treatment for reducing both. Findings are discussed in terms of applications to cognitive-behavioral therapies for treatment of PTSD, such as incorporating mild, innately stressful stimuli into virtual reality therapy.
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Affiliation(s)
- Lauren B Burhans
- Blanchette Rockefeller Neurosciences Institute, West Virginia University
| | | | - Bernard G Schreurs
- Blanchette Rockefeller Neurosciences Institute, West Virginia University
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47
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Hawkins RD, Byrne JH. Associative learning in invertebrates. Cold Spring Harb Perspect Biol 2015; 7:cshperspect.a021709. [PMID: 25877219 DOI: 10.1101/cshperspect.a021709] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This work reviews research on neural mechanisms of two types of associative learning in the marine mollusk Aplysia, classical conditioning of the gill- and siphon-withdrawal reflex and operant conditioning of feeding behavior. Basic classical conditioning is caused in part by activity-dependent facilitation at sensory neuron-motor neuron (SN-MN) synapses and involves a hybrid combination of activity-dependent presynaptic facilitation and Hebbian potentiation, which are coordinated by trans-synaptic signaling. Classical conditioning also shows several higher-order features, which might be explained by the known circuit connections in Aplysia. Operant conditioning is caused in part by a different type of mechanism, an intrinsic increase in excitability of an identified neuron in the central pattern generator (CPG) for feeding. However, for both classical and operant conditioning, adenylyl cyclase is a molecular site of convergence of the two signals that are associated. Learning in other invertebrate preparations also involves many of the same mechanisms, which may contribute to learning in vertebrates as well.
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Affiliation(s)
- Robert D Hawkins
- Department of Neuroscience, Columbia University, New York, New York 10032 New York State Psychiatric Institute, New York, New York 10032
| | - John H Byrne
- Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, Houston, Texas 77030
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