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Rivi V, Batabyal A, Benatti C, Sarti P, Blom JMC, Tascedda F, Lukowiak K. A translational and multidisciplinary approach to studying the Garcia effect, a higher form of learning with deep evolutionary roots. J Exp Biol 2024; 227:jeb247325. [PMID: 38639079 DOI: 10.1242/jeb.247325] [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] [Indexed: 04/20/2024]
Abstract
Animals, including humans, learn and remember to avoid a novel food when its ingestion is followed, hours later, by sickness - a phenomenon initially identified during World War II as a potential means of pest control. In the 1960s, John Garcia (for whom the effect is now named) demonstrated that this form of conditioned taste aversion had broader implications, showing that it is a rapid but long-lasting taste-specific food aversion with a fundamental role in the evolution of behaviour. From the mid-1970s onward, the principles of the Garcia effect were translated to humans, showing its role in different clinical conditions (e.g. side-effects linked to chemotherapy). However, in the last two decades, the number of studies on the Garcia effect has undergone a considerable decline. Since its discovery in rodents, this form of learning was thought to be exclusive to mammals; however, we recently provided the first demonstration that a Garcia effect can be formed in an invertebrate model organism, the pond snail Lymnaea stagnalis. Thus, in this Commentary, after reviewing the experiments that led to the first characterization of the Garcia effect in rodents, we describe the recent evidence for the Garcia effect in L. stagnalis, which may pave the way for future studies in other invertebrates and mammals. This article aims to inspire future translational and ecological studies that characterize the conserved mechanisms underlying this form of learning with deep evolutionary roots, which can be used to address a range of different biological questions.
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Affiliation(s)
- Veronica Rivi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Anuradha Batabyal
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 1N4
- Department of Physical and Natural Sciences, FLAME University, Pune - 412115, Maharashtra, India
| | - Cristina Benatti
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Pierfrancesco Sarti
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Johanna Maria Catharina Blom
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Fabio Tascedda
- Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- CIB, Consorzio Interuniversitario Biotecnologie, 34148 Trieste, Italy
| | - Ken Lukowiak
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 1N4
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Totani Y, Nakai J, Hatakeyama D, Dyakonova VE, Lukowiak K, Ito E. CNS serotonin content mediating food deprivation-enhanced learning is regulated by hemolymph tryptophan concentration and autophagic flux in the pond snail. Nutr Neurosci 2023; 26:217-227. [PMID: 35156560 DOI: 10.1080/1028415x.2022.2033045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nutritional status affects cognitive function in many types of organisms. In the pond snail Lymnaea stagnalis, 1 day of food deprivation enhances taste aversion learning ability by decreasing the serotonin (5-hydroxytryptamin; 5-HT) content in the central nervous system (CNS). On the other hand, after 5 days of food deprivation, learning ability and the CNS 5-HT concentration return to basal levels. How food deprivation leads to alterations of 5-HT levels in the CNS, however, is unknown. Here, we measured the concentration of the 5-HT precursor tryptophan in the hemolymph and CNS, and demonstrated that the CNS tryptophan concentration was higher in 5-day food-deprived snails than in non-food-deprived or 1-day food-deprived snails, whereas the hemolymph tryptophan concentration was not affected by the duration of food deprivation. This finding suggests the existence of a mediator of the CNS tryptophan concentration independent of food deprivation. To identify the mediator, we investigated autophagic flux in the CNS under different food deprivation conditions. We found that autophagic flux was significantly upregulated by inhibition of the tropomyosin receptor kinase (Trk)-Akt-mechanistic target of rapamycin complex 1 (MTORC1) pathway in the CNS of 5-day food-deprived snails. Moreover, when autophagy was inhibited, the CNS 5-HT content was significantly downregulated in 5-day food-deprived snails. Our results suggest that the hemolymph tryptophan concentration and autophagic flux in the CNS cooperatively regulate learning ability affected by different durations of food deprivation. This mechanism may underlie the selection of behaviors appropriate for animal survival depending on the degree of nutrition.
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Affiliation(s)
- Yuki Totani
- Department of Biology, Waseda University, Tokyo, Japan
| | - Junko Nakai
- Department of Biology, Waseda University, Tokyo, Japan
| | - Dai Hatakeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Varvara E Dyakonova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, AB, Canada
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo, Japan.,Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Fujimoto K, Totani Y, Nakai J, Chikamoto N, Namiki K, Hatakeyama D, Ito E. Identification of Putative Molecules for Adiponectin and Adiponectin Receptor and Their Roles in Learning and Memory in Lymnaea stagnalis. BIOLOGY 2023; 12:biology12030375. [PMID: 36979067 PMCID: PMC10045044 DOI: 10.3390/biology12030375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/20/2023] [Accepted: 02/25/2023] [Indexed: 03/02/2023]
Abstract
Adiponectin enhances insulin sensitivity, which improves cognition in mammals. How adiponectin affects the mechanism’s underlying cognition, however, remains unknown. We hypothesized that experiments using the pond snail Lymnaea stagnalis, which has long been used in learning and memory studies and in which the function of insulin-like peptides affect learning and memory, could clarify the basic mechanisms by which adiponectin affects cognition. We first identified putative molecules of adiponectin and its receptor in Lymnaea. We then examined their distribution in the central nervous system and changes in their expression levels when hemolymph glucose concentrations were intentionally decreased by food deprivation. We also applied an operant conditioning protocol of escape behavior to Lymnaea and examined how the expression levels of adiponectin and its receptor changed after the conditioned behavior was established. The results demonstrate that adiponectin and adiponectin’s receptor expression levels were increased in association with a reduced concentration of hemolymph glucose and that expression levels of both adiponectin and insulin-like peptide receptors were increased after the conditioning behavior was established. Thus, the involvement of the adiponectin-signaling cascade in learning and memory in Lymnaea was suggested to occur via changes in the glucose concentrations and the activation of insulin.
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Affiliation(s)
- Kanta Fujimoto
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
| | - Yuki Totani
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
| | - Junko Nakai
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
| | | | - Kengo Namiki
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
| | - Dai Hatakeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 770-8514, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo 162-8480, Japan
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence:
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Nakai J, Chikamoto N, Fujimoto K, Totani Y, Hatakeyama D, Dyakonova VE, Ito E. Insulin and Memory in Invertebrates. Front Behav Neurosci 2022; 16:882932. [PMID: 35558436 PMCID: PMC9087806 DOI: 10.3389/fnbeh.2022.882932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022] Open
Abstract
Insulin and insulin-like peptides (ILP) help to maintain glucose homeostasis, whereas insulin-like growth factor (IGF) promotes the growth and differentiation of cells in both vertebrates and invertebrates. It is sometimes difficult to distinguish between ILP and IGF in invertebrates, however, because in some cases ILP has the same function as IGF. In the present review, therefore, we refer to these peptides as ILP/IGF signaling (IIS) in invertebrates, and discuss the role of IIS in memory formation after classical conditioning in invertebrates. In the arthropod Drosophila melanogaster, IIS is involved in aversive olfactory memory, and in the nematode Caenorhabditis elegans, IIS controls appetitive/aversive response to NaCl depending on the duration of starvation. In the mollusk Lymnaea stagnalis, IIS has a critical role in conditioned taste aversion. Insulin in mammals is also known to play an important role in cognitive function, and many studies in humans have focused on insulin as a potential treatment for Alzheimer’s disease. Although analyses of tissue and cellular levels have progressed in mammals, the molecular mechanisms, such as transcriptional and translational levels, of IIS function in cognition have been far advanced in studies using invertebrates. We anticipate that the present review will help to pave the way for studying the effects of insulin, ILPs, and IGFs in cognitive function across phyla.
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Affiliation(s)
- Junko Nakai
- Department of Biology, Waseda University, Tokyo, Japan
| | | | | | - Yuki Totani
- Department of Biology, Waseda University, Tokyo, Japan
| | - Dai Hatakeyama
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Varvara E. Dyakonova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo, Japan
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- *Correspondence: Etsuro Ito
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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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Another Example of Conditioned Taste Aversion: Case of Snails. BIOLOGY 2020; 9:biology9120422. [PMID: 33256267 PMCID: PMC7760351 DOI: 10.3390/biology9120422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/16/2020] [Accepted: 11/24/2020] [Indexed: 12/11/2022]
Abstract
Simple Summary It is important to decide what to eat and what not to eat in the life. Children are likely to reject new foods. When eating a new food results in a negative experience, the child will avoid that specific food in the future. This phenomenon is called ‘conditioned taste aversion’ in mammals, and it is considered necessary for survival by preventing subsequent ingestion of sickening foods. Many researchers study the same kind of phenomenon in invertebrates, too. For example, the formation of conditioned taste aversion was found in the pond snail, Lymnaea stagnalis, with the selective associability between a sweet sucrose solution and a bitter KCl solution. A sweet food attracts many kinds of animals, resulting in the feeding response, whereas a KCl solution is an aversive stimulus, inducing a withdrawal response in snails. After repeated temporally-contingent presentations of these two stimuli, the sucrose solution no longer elicits a feeding response, and this phenomenon persists for a long term. In the present review, we first outline the mechanisms of conditioned taste aversion in mammals, then introduce the conditioned taste aversion in snails, and compare them. Furthermore, the molecular events in snails are discussed, suggesting the general mechanism in conditioned taste aversion. Abstract Conditioned taste aversion (CTA) in mammals has several specific characteristics: (1) emergence of a negative symptom in subjects due to selective association with a taste-related stimulus, (2) robust long-term memory that is resistant to extinction induced by repeated presentation of the conditioned stimulus (CS), (3) a very-long-delay presentation of the unconditioned stimulus (US), and (4) single-trial learning. The pond snail, Lymnaea stagnalis, can also form a CTA. Although the negative symptoms, like nausea, in humans cannot be easily observed in invertebrate animal models of CTA, all the other characteristics of CTA seem to be present in snails. Selective associability was confirmed using a sweet sucrose solution and a bitter KCl solution. Once snails form a CTA, repeated presentation of the CS does not extinguish the CTA. A long interstimulus interval between the CS and US, like in trace conditioning, still results in the formation of a CTA in snails. Lastly, even single-trial learning has been demonstrated with a certain probability. In the present review, we compare, in detail, CTA in mammals and snails, and discuss the possible molecular events in CTA.
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Totani Y, Nakai J, Hatakeyama D, Ito E. Memory-enhancing effects of short-term fasting. THE EUROPEAN ZOOLOGICAL JOURNAL 2020. [DOI: 10.1080/24750263.2020.1827053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Y. Totani
- Department of Biology, Waseda University, Tokyo, Japan
| | - J. Nakai
- Department of Biology, Waseda University, Tokyo, Japan
| | - D. Hatakeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - E. Ito
- Department of Biology, Waseda University, Tokyo, Japan
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Features of behavioral changes underlying conditioned taste aversion in the pond snail Lymnaea stagnalis. INVERTEBRATE NEUROSCIENCE 2020; 20:8. [DOI: 10.1007/s10158-020-00241-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/25/2020] [Indexed: 12/11/2022]
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Induction of LTM following an Insulin Injection. eNeuro 2020; 7:ENEURO.0088-20.2020. [PMID: 32291265 PMCID: PMC7218004 DOI: 10.1523/eneuro.0088-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/21/2020] [Accepted: 03/26/2020] [Indexed: 02/06/2023] Open
Abstract
The pond snail Lymnaea stagnalis learns conditioned taste aversion (CTA) and consolidates it into long-term memory (LTM). One-day food-deprived snails (day 1 snails) show the best CTA learning and memory, whereas more severely food-deprived snails (5 d) do not express good memory. However, previous studies showed that CTA-LTM was indeed formed in 5-d food-deprived snails (day 5 snails), but its recall was prevented by the effects of food deprivation. CTA-LTM recall in day 5 snails was expressed following 7 d of feeding and then 1 d of food deprivation (day 13 snails). In the present study, we thus hypothesized that memory recall occurs because day 13 snails are in an optimal internal state. One day of food deprivation before the memory test in day 13 snails increased the mRNA level of molluscan insulin-related peptide (MIP) in the CNS. Thus, we further hypothesized that an injection of insulin into day 5 snails following seven additional days with access to food (day 12 snails) activates CTA neurons and mimics the food deprivation state before the memory test in day 13 snails. Day 12 snails injected with insulin could recall the memory. In addition, the simultaneous injection of an anti-insulin receptor antibody and insulin into day 12 snails did not allow memory recall. Insulin injection also decreased the hemolymph glucose concentration. Together, the results suggest that an optimal internal state (i.e., a spike in insulin release and specific glucose levels) are necessary for LTM recall following CTA training in snails.
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Rivi V, Benatti C, Colliva C, Radighieri G, Brunello N, Tascedda F, Blom JMC. Lymnaea stagnalis as model for translational neuroscience research: From pond to bench. Neurosci Biobehav Rev 2019; 108:602-616. [PMID: 31786320 DOI: 10.1016/j.neubiorev.2019.11.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/24/2019] [Accepted: 11/25/2019] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to illustrate how a reductionistic, but sophisticated, approach based on the use of a simple model system such as the pond snail Lymnaea stagnalis (L. stagnalis), might be useful to address fundamental questions in learning and memory. L. stagnalis, as a model, provides an interesting platform to investigate the dialog between the synapse and the nucleus and vice versa during memory and learning. More importantly, the "molecular actors" of the memory dialogue are well-conserved both across phylogenetic groups and learning paradigms, involving single- or multi-trials, aversion or reward, operant or classical conditioning. At the same time, this model could help to study how, where and when the memory dialog is impaired in stressful conditions and during aging and neurodegeneration in humans and thus offers new insights and targets in order to develop innovative therapies and technology for the treatment of a range of neurological and neurodegenerative disorders.
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Affiliation(s)
- V Rivi
- Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - C Benatti
- Dept. of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy; Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - C Colliva
- Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - G Radighieri
- Dept. of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - N Brunello
- Dept. of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - F Tascedda
- Dept. of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy; Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - J M C Blom
- Dept. of Education and Human Sciences, University of Modena and Reggio Emilia, Modena, Italy; Centre of Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy.
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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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Totani Y, Aonuma H, Oike A, Watanabe T, Hatakeyama D, Sakakibara M, Lukowiak K, Ito E. Monoamines, Insulin and the Roles They Play in Associative Learning in Pond Snails. Front Behav Neurosci 2019; 13:65. [PMID: 31001093 PMCID: PMC6454038 DOI: 10.3389/fnbeh.2019.00065] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 03/14/2019] [Indexed: 12/28/2022] Open
Abstract
Molluscan gastropods have long been used for studying the cellular and molecular mechanisms underlying learning and memory. One such gastropod, the pond snail Lymnaea stagnalis, exhibits long-term memory (LTM) following both classical and operant conditioning. Using Lymnaea, we have successfully elucidated cellular mechanisms of learning and memory utilizing an aversive classical conditioning procedure, conditioned taste aversion (CTA). Here, we present the behavioral changes following CTA training and show that the memory score depends on the duration of food deprivation. Then, we describe the relationship between the memory scores and the monoamine contents of the central nervous system (CNS). A comparison of learning capability in two different strains of Lymnaea, as well as the filial 1 (F1) cross from the two strains, presents how the memory scores are correlated in these populations with monoamine contents. Overall, when the memory scores are better, the monoamine contents of the CNS are lower. We also found that as the insulin content of the CNS decreases so does the monoamine contents which are correlated with higher memory scores. The present review deepens the relationship between monoamine and insulin contents with the memory score.
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Affiliation(s)
- Yuki Totani
- Department of Biology, Waseda University, Tokyo, Japan
| | - Hitoshi Aonuma
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Akira Oike
- Department of Biology, Waseda University, Tokyo, Japan
| | - Takayuki Watanabe
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Dai Hatakeyama
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Manabu Sakakibara
- Research Organization for Nano and Life Innovation, Waseda University, Tokyo, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo, Japan
- Research Organization for Nano and Life Innovation, Waseda University, Tokyo, Japan
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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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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14
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Swinton E, de Freitas E, Swinton C, Shymansky T, Hiles E, Zhang J, Rothwell C, Lukowiak K. Green tea and cocoa enhance cognition in Lymnaea. Commun Integr Biol 2018; 11:e1434390. [PMID: 29497476 PMCID: PMC5824930 DOI: 10.1080/19420889.2018.1434390] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 02/05/2023] Open
Abstract
A flavonoid, (-)-epicatechi (Epi), enhances long-term memory (LTM) formation in Lymnaea and reverses memory obstruction caused by stress. Many foods contain substantial amounts of Epi, (e.g. green tea and cocoa). In humans eating such foods may directly or indirectly enhance cognition. We directly test whether operant conditioning training Lymnaea in these natural foods result in the same effects as training snails in pure Epi. We found that exposure to products containing high concentrations of Epi (e.g. green tea and cocoa) during training enhanced memory formation and could even reverse a learning and memory deficit brought about by stress. Epi can be photo-inactivated by exposure to ultraviolet light. We found that following photo-inactivation of Epi, memory enhancement did not occur. Photo-inactivation of foods containing Epi (e,g. green tea) blocked their ability to enhance LTM. Our data are thus consistent with the hypothesis that dietary sources of Epi can have positive benefits on cognitive ability and be able to reverse memory aversive states.
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Affiliation(s)
- Erin Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Emily de Freitas
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Cayley Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tamila Shymansky
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Emily Hiles
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jack Zhang
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Cailin Rothwell
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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15
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Aonuma H, Totani Y, Kaneda M, Nakamura R, Watanabe T, Hatakeyama D, Dyakonova VE, Lukowiak K, Ito E. Effects of 5-HT and insulin on learning and memory formation in food-deprived snails. Neurobiol Learn Mem 2018; 148:20-29. [DOI: 10.1016/j.nlm.2017.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 12/08/2017] [Accepted: 12/29/2017] [Indexed: 01/20/2023]
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16
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de Weerd L, Hermann PM, Wildering WC. Linking the 'why' and 'how' of ageing: evidence for somatotropic control of long-term memory function in the pond snail Lymnaea stagnalis. ACTA ACUST UNITED AC 2017; 220:4088-4094. [PMID: 28954817 DOI: 10.1242/jeb.167395] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/22/2017] [Indexed: 12/11/2022]
Abstract
Organisms live on a budget; hence, they cannot maximize all their activities at the same time. Instead, they must prioritize how they spend limiting resources on the many processes they rely on in their lives. Among others, they are thought to economize on the maintenance and repair processes required for survival in favour of maximizing reproduction, with ageing as a consequence. We investigate the biological mechanisms of neuronal ageing. Using Lymnaea stagnalis, we have previously described various aspects of age-associated neuronal decline and appetitive long-term memory failure. In view of postulated trade-offs between somatic maintenance and reproduction, we tested for interactions between resource allocation mechanisms and brain function. We show that removal of the lateral lobes, which are key regulators of energy balance in L. stagnalis, increases body mass and enhances appetitive learning, raising the possibility that the lateral lobes are one of the sites where the 'why' and 'how' of (neuronal) ageing meet.
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Affiliation(s)
- Lis de Weerd
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary T2N 1N4, Alberta, Canada
| | - Petra M Hermann
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary T2N 1N4, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary T2N 4N1, Alberta, Canada
| | - Willem C Wildering
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary T2N 1N4, Alberta, Canada .,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary T2N 4N1, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary T2N 4N1, Alberta, Canada
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17
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Affiliation(s)
- E. Ito
- Department of Biology, Waseda University , Tokyo, Japan
| | - Y. Totani
- Department of Biology, Waseda University , Tokyo, Japan
| | - A. Oike
- Department of Biology, Waseda University , Tokyo, Japan
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18
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Aonuma H, Kaneda M, Hatakeyama D, Watanabe T, Lukowiak K, Ito E. Weak involvement of octopamine in aversive taste learning in a snail. Neurobiol Learn Mem 2017; 141:189-198. [DOI: 10.1016/j.nlm.2017.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 04/20/2017] [Accepted: 04/23/2017] [Indexed: 01/06/2023]
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19
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Sunada H, Lukowiak K, Ito E. Cerebral Giant Cells are Necessary for the Formation and Recall of Memory of Conditioned Taste Aversion inLymnaea. Zoolog Sci 2017; 34:72-80. [DOI: 10.2108/zs160152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Aonuma H, Kaneda M, Hatakeyama D, Watanabe T, Lukowiak K, Ito E. Relationship between the grades of a learned aversive-feeding response and the dopamine contents in Lymnaea. Biol Open 2016; 5:1869-1873. [PMID: 27815244 PMCID: PMC5200912 DOI: 10.1242/bio.021634] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pond snail Lymnaea learns conditioned taste aversion (CTA) and remembers not to respond to food substances that initially cause a feeding response. The possible relationship between how well snails learn to follow taste-aversion training and brain dopamine contents is not known. We examined this relationship and found the following: first, snails in the act of eating just before the commencement of CTA training were poor learners and had the highest dopamine contents in the brain; second, snails which had an ad libitum access to food, but were not eating just before training, were average learners and had lower dopamine contents; third, snails food-deprived for one day before training were the best learners and had significantly lower contents of dopamine compared to the previous two cohorts. There was a negative correlation between the CTA grades and the brain dopamine contents in these three cohorts. Fourth, snails food-deprived for five days before training were poor learners and had higher dopamine contents. Thus, severe hunger increased the dopamine content in the brain. Because dopamine functions as a reward transmitter, CTA in the severely deprived snails (i.e. the fourth cohort) was thought to be mitigated by a high dopamine content.
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Affiliation(s)
- Hitoshi Aonuma
- Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0811, Japan.,CREST, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Mugiho Kaneda
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Dai Hatakeyama
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Takayuki Watanabe
- Research Center of Mathematics for Social Creativity, Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0811, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Etsuro Ito
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan .,Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan
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21
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Report on the 13th symposium on invertebrate neurobiology held 26-30 August 2015 at the Balaton Limnological Institute, MTA Centre for ecological research of the Hungarian Academy of Sciences, Tihany, Hungary. INVERTEBRATE NEUROSCIENCE 2016; 16:3. [PMID: 27149972 DOI: 10.1007/s10158-016-0186-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This report summarizes the lectures and posters presented at the International Society for Invertebrate Neurobiology's 13th symposium held 26-30 August 2015, at the Balaton Limnological Institute, MTA Centre for Ecological Research, Tihany, Hungary. The symposium provided an opportunity for scientists working on a range of topics in invertebrate neurobiology to meet and present their research and discuss ways to advance the discipline.
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22
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Function of insulin in snail brain in associative learning. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 201:969-81. [PMID: 26233474 DOI: 10.1007/s00359-015-1032-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 07/23/2015] [Accepted: 07/24/2015] [Indexed: 12/23/2022]
Abstract
Insulin is well known as a hormone regulating glucose homeostasis across phyla. Although there are insulin-independent mechanisms for glucose uptake in the mammalian brain, which had contributed to a perception of the brain as an insulin-insensitive organ for decades, the finding of insulin and its receptors in the brain revolutionized the concept of insulin signaling in the brain. However, insulin's role in brain functions, such as cognition, attention, and memory, remains unknown. Studies using invertebrates with their open blood-vascular system have the promise of promoting a better understanding of the role played by insulin in mediating/modulating cognitive functions. In this review, the relationship between insulin and its impact on long-term memory (LTM) is discussed particularly in snails. The pond snail Lymnaea stagnalis has the ability to undergo conditioned taste aversion (CTA), that is, it associatively learns and forms LTM not to respond with a feeding response to a food that normally elicits a robust feeding response. We show that molluscan insulin-related peptides are up-regulated in snails exhibiting CTA-LTM and play a key role in the causal neural basis of CTA-LTM. We also survey the relevant literature of the roles played by insulin in learning and memory in other phyla.
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23
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Ito E, Yamagishi M, Hatakeyama D, Watanabe T, Fujito Y, Dyakonova V, Lukowiak K. Memory block: a consequence of conflict resolution. ACTA ACUST UNITED AC 2015; 218:1699-704. [PMID: 25883377 DOI: 10.1242/jeb.120329] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/05/2015] [Indexed: 11/20/2022]
Abstract
Food deprivation for 1 day in the pond snail Lymnaea stagnalis before aversive classical conditioning results in optimal conditioned taste aversion (CTA) and long-term memory (LTM) formation, whereas 5-day food deprivation before training does not. We hypothesize that snails do in fact learn and form LTM when trained after prolonged food deprivation, but that severe food deprivation blocks their ability to express memory. We trained 5-day food-deprived snails under various conditions, and found that memory was indeed formed but is overpowered by severe food deprivation. Moreover, CTA-LTM was context dependent and was observed only when the snails were in a context similar to that in which the training occurred.
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Affiliation(s)
- Etsuro Ito
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Miki Yamagishi
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Dai Hatakeyama
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Takayuki Watanabe
- Laboratory of Neurocybernetics, Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan
| | - Yutaka Fujito
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Varvara Dyakonova
- Laboratory of Comparative Physiology, Institute for Developmental Biology, RAS, Moscow 119909, Russia
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
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24
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Yamagishi M, Watanabe T, Hatakeyama D, Ito E. Effects of serotonin on the heartbeat of pond snails in a hunger state. Biophysics (Nagoya-shi) 2015; 11:1-5. [PMID: 27493507 PMCID: PMC4736785 DOI: 10.2142/biophysics.11.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/05/2014] [Indexed: 12/18/2022] Open
Abstract
Serotonin (5-hydroxytryptamine: 5-HT) is a multimodal transmitter that controls both feeding response and heartbeat in snails. However, the effects of 5-HT on the hunger state are still unknown. We therefore examined the relation among the hunger state, the heartbeat rate and the 5-HT action in food-starved snails. We found that the hunger state was significantly distinguished by the heartbeat rate in snails. The heartbeat rate was high in the food-satiated snails, whereas it was low in the food-starved snails. An increase in 5-HT concentration in the body boosted the heartbeat rate in the food-starved snails, but did not affect the rate in the food-satiated snails. These results suggest that 5-HT application may mimic the change from a starvation to a satiation state normally achieved by direct ingestion of food.
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Affiliation(s)
- Miki Yamagishi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Takayuki Watanabe
- Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan
| | - Dai Hatakeyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
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25
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Ito E, Yamagishi M, Takigami S, Sakakibara M, Fujito Y, Lukowiak K. The Yerkes-Dodson law and appropriate stimuli for conditioned taste aversion in Lymnaea. J Exp Biol 2014; 218:336-9. [DOI: 10.1242/jeb.113266] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The pond snail Lymnaea stagnalis can learn conditioned taste aversion and then consolidate it into long-term memory (LTM). A high voltage electric shock was used as the unconditioned stimulus (US), whereas we previously used KCl. We varied both the strength of the conditioned stimulus (CS) and US to determine if the so-called Yerkes-Dodson law prevailed. This is an empirical relationship between the state of arousal and LTM formation, showing that there is an optimal level of arousal leading to memory formation. However, too little or too much arousal results in poorer LTM. We found here that the most appropriate stimuli to use in taste aversion training in Lymnaea were a 10 mmol l-1 sucrose solution as the CS and a 3-s electric shock as the US.
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