1
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Davidson GL, Cienfuegos IA, Dalesman S. Antibiotic-altered gut microbiota explain host memory plasticity and disrupt pace-of-life covariation for an aquatic snail. THE ISME JOURNAL 2024; 18:wrae078. [PMID: 38811063 PMCID: PMC11136587 DOI: 10.1093/ismejo/wrae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/21/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024]
Abstract
There is mounting evidence that intestinal microbiota communities and their genes (the gut microbiome) influence how animals behave and interact with their environment, driving individual variation. Individual covariation in behavioural, physiological, and cognitive traits among individuals along a fast-slow continuum is thought to arise because these traits are linked as part of an adaptive pace-of-life strategy. Yet paradoxically, trait intercorrelation is absent or disrupted in some populations but not others. Here, we provide experimental evidence from aquatic pond snails (Lymnaea stagnalis) that environmental stressors and the gut microbiota explain host phenotypic plasticity and disrupted covariation among traits. Antibiotic exposure at varying levels of ecologically relevant concentrations had multiple effects starting with gut microbiota diversity, differential abundance, and inferred function. Memory declined in line with antibiotic concentrations that caused the most profound gut microbiota disruption, and although pace-of-life traits remained rigid, their covariation did not. Moreover, inferred microbial metabolic pathways with biologically relevant host functions explained individual and treatment variation in phenotypes. Together, our results point to the gut microbiome as a proximate mechanism influencing the emergence and maintenance of phenotypic variation within populations and highlights the need to decipher whether the gut microbiome's sensitivity to environmental pollution facilitates adaptive or maladaptive phenotypic plasticity.
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Affiliation(s)
- Gabrielle L Davidson
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, United Kingdom
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Ignacio A Cienfuegos
- Department of Life Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, United Kingdom
| | - Sarah Dalesman
- Department of Life Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, United Kingdom
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2
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Dyakonova VE. DNA Instability in Neurons: Lifespan Clock and Driver of Evolution. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1719-1731. [PMID: 38105193 DOI: 10.1134/s0006297923110044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 07/19/2023] [Accepted: 09/20/2023] [Indexed: 12/19/2023]
Abstract
In the last ten years, the discovery of neuronal DNA postmitotic instability has changed the theoretical landscape in neuroscience and, more broadly, biology. In 2003, A. M. Olovnikov suggested that neuronal DNA is the "initial substrate of aging". Recent experimental data have significantly increased the likelihood of this hypothesis. How does neuronal DNA accumulate damage and in what genome regions? What factors contribute to this process and how are they associated with aging and lifespan? These questions will be discussed in the review. In the course of Metazoan evolution, the instability of neuronal DNA has been accompanied by searching for the pathways to reduce the biological cost of brain activity. Various processes and activities, such as sleep, evolutionary increase in the number of neurons in the vertebrate brain, adult neurogenesis, distribution of neuronal activity, somatic polyploidy, and RNA editing in cephalopods, can be reconsidered in the light of the trade-off between neuronal plasticity and DNA instability in neurons. This topic is of considerable importance for both fundamental neuroscience and translational medicine.
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Affiliation(s)
- Varvara E Dyakonova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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3
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Rivi V, Batabyal A, Benatti C, Tascedda F, Blom JMC, Lukowiak K. Aspirin reverts lipopolysaccharide-induced learning and memory impairment: first evidence from an invertebrate model system. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:1573-1585. [PMID: 36100758 DOI: 10.1007/s00210-022-02286-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/31/2022] [Indexed: 12/01/2022]
Abstract
By employing a reductionistic (but not simplistic) approach using an established invertebrate model system, the pond snail Lymnaea stagnalis, we investigated whether (1) lipopolysaccharide (LPS)-induced inflammation would cause a sickness state and impair cognitive function, and-if so-(2) would aspirin (acetylsalicylic acid-ASA) restore the impaired cognition. To test our hypotheses, we first determined if the injection of 25 mg (6.25 μg/mL) of Escherichia coli-derived LPS serotype O127:B8 altered homeostatic behavior, aerial respiration, and then determined if LPS altered memory formation when this behavior was operantly conditioned. Next, we determined if ASA altered the LPS-induced changes in both aerial respiration and cognitive functions. LPS induced a sickness state that increased aerial respiration and altered the ability of snails to form or recall long-term memory. ASA reverted the LPS-induced sickness state and thus allowed long-term memory both to be formed and recalled. We confirmed our hypotheses and provided the first evidence in an invertebrate model system that an injection of LPS results in a sickness state that obstructs learning and memory, and this impairment can be prevented by a non-steroidal anti-inflammatory.
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Affiliation(s)
- Veronica Rivi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
| | - Anuradha Batabyal
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Cristina Benatti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - Fabio Tascedda
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
- CIB, Consorzio Interuniversitario Biotecnologie, Trieste, Italy
| | - Joan M C Blom
- CIB, Consorzio Interuniversitario Biotecnologie, Trieste, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Ken Lukowiak
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
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4
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Rivi V, Benatti C, Lukowiak K, Colliva C, Alboni S, Tascedda F, Blom JMC. 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] [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 Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy
| | - Cristina Benatti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, AB, T2N 4N1, Canada
| | - Chiara Colliva
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy
| | - Silvia Alboni
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy
| | - Fabio Tascedda
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,CIB, Consorzio Interuniversitario Biotecnologie, Trieste, Italy
| | - Johanna M C Blom
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy.,Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Via Campi, Modena, 287-41125, Italy
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5
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Fodor I, Hussein AAA, Benjamin PR, Koene JM, Pirger Z. The unlimited potential of the great pond snail, Lymnaea stagnalis. eLife 2020; 9:e56962. [PMID: 32539932 PMCID: PMC7297532 DOI: 10.7554/elife.56962] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/27/2020] [Indexed: 12/14/2022] Open
Abstract
Only a limited number of animal species lend themselves to becoming model organisms in multiple biological disciplines: one of these is the great pond snail, Lymnaea stagnalis. Extensively used since the 1970s to study fundamental mechanisms in neurobiology, the value of this freshwater snail has been also recognised in fields as diverse as host-parasite interactions, ecotoxicology, evolution, genome editing and 'omics', and human disease modelling. While there is knowledge about the natural history of this species, what is currently lacking is an integration of findings from the laboratory and the field. With this in mind, this article aims to summarise the applicability of L. stagnalis and points out that this multipurpose model organism is an excellent, contemporary choice for addressing a large range of different biological questions, problems and phenomena.
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Affiliation(s)
- István Fodor
- NAP Adaptive Neuroethology, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological ResearchTihanyHungary
| | - Ahmed AA Hussein
- Department of Ecological Sciences, Faculty of Sciences, Vrije UniversiteitAmsterdamNetherlands
| | - Paul R Benjamin
- Sussex Neuroscience, School of Life Sciences, University of SussexBrightonUnited Kingdom
| | - Joris M Koene
- Section of Animal Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, Vrije Universiteit AmsterdamAmsterdamNetherlands
| | - Zsolt Pirger
- NAP Adaptive Neuroethology, Department of Experimental Zoology, Balaton Limnological Institute, Centre for Ecological ResearchTihanyHungary
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6
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Swinton E, Swinton C, Lukowiak K. Shell damage leads to enhanced memory formation in Lymnaea. ACTA ACUST UNITED AC 2019; 222:jeb.207571. [PMID: 31431472 DOI: 10.1242/jeb.207571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/11/2019] [Indexed: 12/14/2022]
Abstract
Ecologically relevant stressors alter the ability of the pond snail, Lymnaea stagnalis, to form long-term memory (LTM). Here, we show that an environmentally relevant stressor, shell damage, has a dramatic effect on the enhancement of LTM formation. Damage in the form of a shell clip 24 h before operant conditioning training resulted in long-term memory (LTM) formation following a single 0.5 h training session (TS). Typically, in these snails, two 0.5 h TSs with a 1 h interval between the sessions are required to cause LTM formation. We show here that even with a 72 h interval between shell clip and training, memory enhancement still occurred. The stress associated with shell clip could be mitigated by an ongoing high-Ca2 + pond water environment, an injection of propranolol and a DNA methylation blocker. However, use of an anaesthetic (MgCl2) during the clip or intermittent exposure to the high-Ca2 + pond water environment did not mitigate the stress associated with the shell clip. Shell clip was also sufficient to cause juvenile snails, which neither learn nor form memory, to gain the capacity to form LTM. Together, the experiments demonstrate that shell clipping is an environmentally relevant stressor that can cause enhancement of LTM formation.
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Affiliation(s)
- Erin Swinton
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Cayley Swinton
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
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7
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Dalesman S. Habitat and social context affect memory phenotype, exploration and covariance among these traits. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170291. [PMID: 30104436 PMCID: PMC6107572 DOI: 10.1098/rstb.2017.0291] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2018] [Indexed: 12/28/2022] Open
Abstract
Individual differences in cognitive ability are predicted to covary with other behavioural traits such as exploration and boldness. Selection within different habitats may act to either enhance or break down covariance among traits; alternatively, changing the environmental context in which traits are assessed may result in plasticity that alters trait covariance. Pond snails, Lymnaea stagnalis, from two laboratory strains (more than 20 generations in captivity) and F1 laboratory reared from six wild populations were tested for long-term memory and exploration traits (speed and thigmotaxis) following maintenance in grouped and isolated conditions to determine if isolation: (i) alters memory and exploration; and (ii) alters covariance between memory and exploration. Populations that demonstrated strong memory formation (longer duration) under grouped conditions demonstrated weaker memory formation and reduced both speed and thigmotaxis following isolation. In wild populations, snails showed no relationship between memory and exploration in grouped conditions; however, following isolation, exploration behaviour was negatively correlated with memory, i.e. slow-explorers showing low levels of thigmotaxis formed stronger memories. Laboratory strains demonstrated no covariance among exploration traits and memory independent of context. Together these data demonstrate that the relationship between cognition and exploration traits can depend on both habitat and context-specific trait plasticity.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.
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Affiliation(s)
- Sarah Dalesman
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Penglais, Aberystwyth, Ceredigion SY23 3DA, UK
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8
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Aonuma H, Totani Y, Sakakibara M, Lukowiak K, Ito E. Comparison of brain monoamine content in three populations of Lymnaea that correlates with taste-aversive learning ability. Biophys Physicobiol 2018; 15:129-135. [PMID: 29955564 PMCID: PMC6018436 DOI: 10.2142/biophysico.15.0_129] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/20/2018] [Indexed: 12/01/2022] Open
Abstract
To find a causal mechanism of learning and memory is a heuristically important topic in neuroscience. In the pond snail Lymnaea stagnalis, the following experimental facts have accrued regarding a classical conditioning procedure known as conditioned taste aversion (CTA): (1) one-day food-deprived Dutch snails have superior CTA memory formation; (2) the one-day food-deprived snails have a low monoamine content (e.g., serotonin, dopamine, octopamine) in their central nervous system (CNS); (3) fed or five-day food-deprived snails have poorer CTA memory and a higher monoamine content; (4) the Dutch snails form better CTA memory than the Canadian TC1 strain; and, (5) the F1 cross snails between the Dutch and Canadian TC1 strains also form poor CTA memory. Here, in one-day food-deprived snails, we measured the monoamine content in the CNSs of the 3 populations. In most instances, the monoamine content of the Dutch strain was lower than in the other two populations. The F1 cross snails had the highest monoamine content. A lower monoamine content is correlated with the better CTA memory formation.
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Affiliation(s)
- Hitoshi Aonuma
- Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 060-0811, Japan.,CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Yuki Totani
- Department of Biology, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Manabu Sakakibara
- Research Organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Etsuro Ito
- Department of Biology, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan.,Research Organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan.,WASEDA Bioscience Research Institute in Singapore, 138667, Singapore.,Graduate Institute of Medicine and Center for Stem Cell Research, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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9
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Sunada H, Watanabe T, Hatakeyama D, Lee S, Forest J, Sakakibara M, Ito E, Lukowiak K. Pharmacological effects of cannabinoids on learning and memory in Lymnaea. ACTA ACUST UNITED AC 2018; 220:3026-3038. [PMID: 28855319 DOI: 10.1242/jeb.159038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 06/07/2017] [Indexed: 12/22/2022]
Abstract
Cannabinoids are hypothesized to play an important role in modulating learning and memory formation. Here, we identified mRNAs expressed in Lymnaeastagnalis central nervous system that encode two G-protein-coupled receptors (Lymnaea CBr-like 1 and 2) that structurally resemble mammalian cannabinoid receptors (CBrs). We found that injection of a mammalian CBr agonist WIN 55,212-2 (WIN 55) into the snail before operant conditioning obstructed learning and memory formation. This effect of WIN 55 injection persisted for at least 4 days following its injection. A similar obstruction of learning and memory occurred when a severe traumatic stimulus was delivered to L. stagnalis In contrast, injection of a mammalian CBr antagonist AM 251 enhanced long-term memory formation in snails and reduced the duration of the effects of the severe traumatic stressor on learning and memory. Neither WIN 55 nor AM 251 altered normal homeostatic aerial respiratory behaviour elicited in hypoxic conditions. Our results suggest that putative cannabinoid receptors mediate stressful stimuli that alter learning and memory formation in Lymnaea This is also the first demonstration that putative CBrs are present in Lymnaea and play a key role in learning and memory formation.
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Affiliation(s)
- Hiroshi Sunada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 4N1.,Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa 769-2193, Japan
| | - Takayuki Watanabe
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 060-0811, Japan
| | - Dai Hatakeyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa 769-2193, Japan
| | - Sangmin Lee
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 4N1
| | - Jeremy Forest
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 4N1
| | - Manabu Sakakibara
- School of High-Technology for Human Welfare, Tokai University, Numazu, Shizuoka 410-0321, Japan
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa 769-2193, Japan .,Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada T2N 4N1
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10
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Shymansky T, Hughes E, Rothwell CM, Lukowiak K. Propranolol disrupts consolidation of emotional memory in Lymnaea. Neurobiol Learn Mem 2018; 149:1-9. [DOI: 10.1016/j.nlm.2018.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/08/2018] [Accepted: 01/23/2018] [Indexed: 01/30/2023]
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11
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Sunada H, Totani Y, Nakamura R, Sakakibara M, Lukowiak K, Ito E. Two Strains of Lymnaea stagnalis and the Progeny from Their Mating Display Differential Memory-Forming Ability on Associative Learning Tasks. Front Behav Neurosci 2017; 11:161. [PMID: 28955210 PMCID: PMC5601001 DOI: 10.3389/fnbeh.2017.00161] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/16/2017] [Indexed: 01/11/2023] Open
Abstract
The pond snail Lymnaea stagnalis learns and forms long-term memory (LTM) following both operant conditioning of aerial respiratory behavior and classical conditioning of taste aversive behavior. In the present study, we examined whether there are interstrain differences in the ability to form LTM following these two types of conditioning. A strain of Lymnaea (TC1) collected in Alberta, Canada exhibits superior memory-forming ability following aerial respiratory operant conditioning compared to a laboratory-reared strain of Lymnaea from Netherlands known as the Dutch strain. We asked whether the offspring of the Canadian TC1 and Dutch snails (i.e., filial 1 (F1) cross snails) would have the superior memory ability and found, rather, that their memory ability was average like the Dutch snails. That is, the Canadian TC1 snails have superior ability for LTM formation following aerial respiratory operant conditioning, but the Dutch and the generated F1 cross have average ability for memory forming. We next examined the Canadian TC1, Dutch and F1 cross snails for their ability to learn and form memory following conditioned taste aversion (CTA). All three populations showed similar associative CTA responses. However, both LTM formation and the ratio of good-to-poor performers in the memory retention test were much better in the Dutch snails than the Canadian TC1 and F1 cross snails. The memory abilities of the Canadian TC1 and F1 cross snails were average. Our present findings, therefore, suggest that snails of different strains have different memory abilities, and the F1 cross snails do not inherit the memory ability from the smart strain. To our knowledge, there have been a limited number of studies examining differences in memory ability among invertebrate strains, with the exception of studies using mutant flies.
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Affiliation(s)
- Hiroshi Sunada
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri UniversitySanuki, Japan
| | - Yuki Totani
- Department of Biology, Waseda UniversityTokyo, Japan
| | | | - Manabu Sakakibara
- Research Organization for Nano and Life Innovation, Waseda UniversityTokyo, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of CalgaryCalgary, AB, Canada
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri UniversitySanuki, Japan.,Department of Biology, Waseda UniversityTokyo, Japan.,Research Organization for Nano and Life Innovation, Waseda UniversityTokyo, Japan.,WASEDA Bioscience Research Institute in SingaporeSingapore, Singapore.,Lipid Science and Aging Research Center and Center for Stem Cell Research, Kaohsiung Medical UniversityKaohsiung, Taiwan
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12
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Hughes E, Shymansky T, Swinton E, Lukowiak KS, Swinton C, Sunada H, Protheroe A, Phillips I, Lukowiak K. Strain-specific differences of the effects of stress on memory in Lymnaea. J Exp Biol 2017; 220:891-899. [DOI: 10.1242/jeb.149161] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022]
Abstract
ABSTRACT
Stress alters the ability to form, recall and maintain memory according to the Yerkes–Dodson/Hebb (YDH) law. The effects of environmentally relevant stressors, such as low environmental calcium and crowding, on learning and memory have previously been described in a laboratory-reared ‘average’ strain of Lymnaea stagnalis (i.e. the Dutch strain) as well as two strains of freshly collected L. stagnalis with enhanced memory formation abilities (i.e. ‘smart’ snails). Here, we use L. stagnalis to study the effects of other environmentally relevant stressors on memory formation in two other strains of freshly collected snails, one ‘smart’ and one ‘average’. The stressors we examined are thermal, resource restriction combined with food odour, predator detection and, for the first time, tissue injury (shell damage). We show that the same stressor has significantly different effects on memory formation depending on whether snails are ‘smart’ or ‘average’. Specifically, our data suggest that a stressor or a combination of stressors act to enhance memory in ‘average’ snails but obstruct memory formation in ‘smart’ snails. These results are consistent with the YDH law and our hypothesis that ‘smart’ snails are more easily stressed than ‘average’ snails.
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Affiliation(s)
- Emily Hughes
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Tamila Shymansky
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Erin Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Kai S. Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Cayley Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Hiroshi Sunada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Amy Protheroe
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Iain Phillips
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
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13
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Forest J, Sunada H, Dodd S, Lukowiak K. Training Lymnaea in the presence of a predator scent results in a long-lasting ability to form enhanced long-term memory. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2016; 202:399-409. [PMID: 27138222 DOI: 10.1007/s00359-016-1086-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 04/17/2016] [Accepted: 04/19/2016] [Indexed: 12/25/2022]
Abstract
Lymnaea exposed to crayfish effluent (CE) gain an enhanced ability to form long-term memory (LTM). We test the hypothesis that a single CE exposure and operant conditioning training leads to long lasting changes in the capability of snails to form LTM when tested in pond water four weeks later. We trained both juvenile and adult snails with a single 0.5 h training session in CE and show that LTM was present 24 h later. Snails trained in a similar manner in just pond water show no LTM. We then asked if such training in CE conferred enhanced memory forming capabilities on these snails four weeks later. That is, would LTM be formed in these snails four weeks later following a single 0.5 h training session in pond water? We found that both adult and juvenile snails previously trained in CE one month previously had enhanced LTM formation abilities. The injection of a DNA methylation blocker, 5-AZA, prior to training in adult snails blocked enhanced LTM formation four weeks later. Finally, this enhanced LTM forming ability was not passed on to the next generation of snails.
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Affiliation(s)
- Jeremy Forest
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.,University Claude Bernard, Lyon, France
| | - Hiroshi Sunada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Shawn Dodd
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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Knezevic B, Komatsuzaki Y, de Freitas E, Lukowiak K. A flavanoid component of chocolate quickly reverses an imposed memory deficit. ACTA ACUST UNITED AC 2016; 219:816-23. [PMID: 26823103 DOI: 10.1242/jeb.130765] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/30/2015] [Indexed: 01/27/2023]
Abstract
The ability to remember is influenced by environmental and lifestyle factors, such as stress and diet. A flavanol contained in chocolate, epicatechin (Epi), has been shown to enhance long-term memory (LTM) formation in Lymnaea. Combining two stressors (low-calcium pond water and crowding) blocks learning and all forms of memory; that is, this combination of environmentally relevant stressors creates a memory-unfriendly state. We tested the hypothesis that Epi will immediately reverse the memory-unfriendly state, i.e. that snails in the memory-deficit state when trained in Epi will immediately become competent to learn and form memory. We found that Epi not only reverses the memory-deficit state but also further enhances LTM formation. Thus, a naturally occurring bioactive plant compound can overcome a memory-unfriendly state. This supports the idea that bioactive substances may mitigate memory-making deficits that, for example, occur with ageing.
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Affiliation(s)
- Bogdan Knezevic
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Yoshimasa Komatsuzaki
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Emily de Freitas
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
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15
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Dodd SX, Lukowiak K. Sequential exposure to a combination of stressors blocks memory reconsolidation in Lymnaea. J Exp Biol 2015; 218:923-30. [PMID: 25617463 DOI: 10.1242/jeb.114876] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Stress alters the formation of long-term memory (LTM) in Lymnaea. When snails are exposed to more than one stressor, however, how the memory is altered becomes complicated. Here, we investigated how multiple stressors applied in a specific pattern affect an aspect of memory not often studied in regards to stress - reconsolidation. We hypothesized that the application of a sequence of stressors would block the reconsolidation process. Reconsolidation occurs following activation of a previously formed memory. Sequential crowding and handling were used as the stressors to block reconsolidation. When the two stressors were sequentially presented immediately following memory activation, reconsolidation was blocked. However, if the sequential presentation of the stressors was delayed for 1 h after memory activation, reconsolidation was not blocked. That is, LTM was observed. Finally, presentation of either stressor alone did not block reconsolidation. Thus, stressors can block reconsolidation, which may be preferable to pharmacological manipulations.
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Affiliation(s)
- Shawn Xavier Dodd
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
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Hermann PM, Watson SN, Wildering WC. Phospholipase A2 - nexus of aging, oxidative stress, neuronal excitability, and functional decline of the aging nervous system? Insights from a snail model system of neuronal aging and age-associated memory impairment. Front Genet 2014; 5:419. [PMID: 25538730 PMCID: PMC4255604 DOI: 10.3389/fgene.2014.00419] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 11/13/2014] [Indexed: 02/02/2023] Open
Abstract
The aging brain undergoes a range of changes varying from subtle structural and physiological changes causing only minor functional decline under healthy normal aging conditions, to severe cognitive or neurological impairment associated with extensive loss of neurons and circuits due to age-associated neurodegenerative disease conditions. Understanding how biological aging processes affect the brain and how they contribute to the onset and progress of age-associated neurodegenerative diseases is a core research goal in contemporary neuroscience. This review focuses on the idea that changes in intrinsic neuronal electrical excitability associated with (per)oxidation of membrane lipids and activation of phospholipase A2 (PLA2) enzymes are an important mechanism of learning and memory failure under normal aging conditions. Specifically, in the context of this special issue on the biology of cognitive aging we portray the opportunities offered by the identifiable neurons and behaviorally characterized neural circuits of the freshwater snail Lymnaea stagnalis in neuronal aging research and recapitulate recent insights indicating a key role of lipid peroxidation-induced PLA2 as instruments of aging, oxidative stress and inflammation in age-associated neuronal and memory impairment in this model system. The findings are discussed in view of accumulating evidence suggesting involvement of analogous mechanisms in the etiology of age-associated dysfunction and disease of the human and mammalian brain.
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Affiliation(s)
- Petra M Hermann
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada ; Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada
| | - Shawn N Watson
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada
| | - Willem C Wildering
- Department of Biological Sciences, University of Calgary Calgary, AB, Canada ; Department of Physiology and Pharmacology, University of Calgary Calgary, AB, Canada ; Hotchkiss Brain Institute, University of Calgary Calgary, AB, Canada
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Lukowiak K, Sunada H, Teskey M, Lukowiak K, Dalesman S. Environmentally relevant stressors alter memory formation in the pond snail Lymnaea. J Exp Biol 2014; 217:76-83. [DOI: 10.1242/jeb.089441] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Stress alters adaptive behaviours such as learning and memory. Stressors can either enhance or diminish learning, memory formation and/or memory recall. We focus attention here on how environmentally relevant stressors alter learning, memory and forgetting in the pond snail, Lymnaea stagnalis. Operant conditioning of aerial respiration causes associative learning that may lead to long-term memory (LTM) formation. However, individual ecologically relevant stressors, combinations of stressors, and bio-active substances can alter whether or not learning occurs or memory forms. While the behavioural memory phenotype may be similar as a result of exposure to different stressors, how each stressor alters memory formation may occur differently. In addition, when a combination of stressors are presented it is difficult to predict ahead of time what the outcome will be regarding memory formation. Thus, how combinations of stressors act is an emergent property of how the snail perceives the stressors.
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Affiliation(s)
- Ken Lukowiak
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Hiroshi Sunada
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Morgan Teskey
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Kai Lukowiak
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, AB, Canada, T2N 4N1
| | - Sarah Dalesman
- Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, AB, Canada, T2N 4N1
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Knezevic B, Lukowiak K. A flavonol, epicatechin, reverses the suppressive effects of a stressor on LTM formation. J Exp Biol 2014; 217:4004-9. [DOI: 10.1242/jeb.110726] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abstract
Learning and subsequent memory formation are influenced by both environmental and lifestyle factors, such as stress and diet. Epicatechin, a plant flavonol found in cocoa, red wine, and green tea enhances long term memory formation (LTM) in Lymnaea; while an ecologically relevant stressor, low calcium pond water, suppress LTM formation. We tested the hypothesis that epicatechin overcomes the suppressive effects of the stressor on LTM formation in the continued presence of the stressor. Snails trained in low calcium pond water exhibit learning but not LTM. Epicatechin (15 mg/L) in control pond water enhances LTM formation. When epicatechin was added to the low calcium pond water an enhanced LTM similar to that seen in control pond water was observed. Thus, a naturally occurring bioactive plant compound was able to overcome the suppressive effects of an ecologically relevant stressor on LTM formation.
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Mita K, Okuta A, Okada R, Hatakeyama D, Otsuka E, Yamagishi M, Morikawa M, Naganuma Y, Fujito Y, Dyakonova V, Lukowiak K, Ito E. What are the elements of motivation for acquisition of conditioned taste aversion? Neurobiol Learn Mem 2014; 107:1-12. [DOI: 10.1016/j.nlm.2013.10.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 11/28/2022]
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Combining stressors that individually impede long-term memory blocks all memory processes. PLoS One 2013; 8:e79561. [PMID: 24223180 PMCID: PMC3819272 DOI: 10.1371/journal.pone.0079561] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 09/24/2013] [Indexed: 12/25/2022] Open
Abstract
The effects of stress on memory are typically assessed individually; however, in reality different stressors are often experienced simultaneously. Here we determined the effect that two environmentally relevant stressors, crowding and low calcium availability, have on memory and neural activity following operant conditioning of aerial respiration in the pond snail, Lymnaea stagnalis. We measured aerial breathing behaviour and activity of a neuron necessary for memory formation, right pedal dorsal 1 (RPeD1), in the central pattern generator (CPG) that drives aerial respiration in untrained animals, and assessed how these traits changed following training. In naïve animals both crowding and combined stressors significantly depressed burst activity in RPeD1 which correlated with a depression in aerial breathing behaviour, whereas low calcium availability had no effect on RPeD1 activity. Following training, changes in burst activity in RPeD1 correlated with behavioural changes, decreasing relative to their naïve state at 3 h and 24 h in control conditions when both intermediate-term memory (ITM: 3 h) and long-term memory (LTM: 24 h) are formed, at 3 h but not 24 h when exposed to individual stressors when only ITM is formed, and did not change in combined stressors (i.e. when no memory is formed). Additionally, we also found that Lymnaea formed short-term memory (STM: 10 min) in the presence of individual stressors or under control conditions, but failed to do so in the presence of combined stressors. Our data demonstrate that by combining stressors that individually block LTM only we can block all memory processes. Therefore the effects of two stressors with similar individual affects on memory phenotype may be additive when experienced in combination.
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Teskey ML, Lukowiak KS, Riaz H, Dalesman S, Lukowiak K. What's hot: the enhancing effects of thermal stress on long-term memory formation in Lymnaea stagnalis. J Exp Biol 2012; 215:4322-9. [DOI: 10.1242/jeb.075960] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Summary
The pond snail, Lymnaea stagnalis, naturally inhabits slow flowing, shallow and stagnant environments in the northern temperate zone. Consequently, it will experience wide temperature fluctuations dependent on prevailing weather conditions. We hypothesize that periods of warming act as a thermal stressor to alter memory formation. Snails were exposed to an acute 1h period of 30°C pond water and we determined how memory formation following operant conditioning of aerial respiration was affected. In snails used here (the Dutch strain), a single 0.5h training session (TS) results in intermediate-term (3h) but not long-term memory (LTM). Applying the thermal stressor during training caused memory enhancement (i.e. LTM lasting 24 h). However, the breathing rate also increased in warm water, which might explain the enhanced memory. Therefore, we applied the thermal stressor (1h at 30°C) up to 4h before or 1h after training. This did not alter baseline breathing rate during the period when snails would experience training. However, the thermal stressor weather experienced prior to or following the single TS, resulted in an enhanced memory that persisted up to 48h (i.e. LTM). We conclude that memory enhancement is due to the stress associated with the thermal stimulus.
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