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Komatsuzaki Y, Lukowiak K. Epicatechin Alters the Activity of a Neuron Necessary for Long-Term Memory of Aerial Respiratory Behavior in Lymnaea stagnalis. Zoolog Sci 2022; 39. [DOI: 10.2108/zs220008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/16/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Yoshimasa Komatsuzaki
- College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary AB T2N 4N1, Canada
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2
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A flavonoid, quercetin, is capable of enhancing long-term memory formation if encountered at different times in the learning, memory formation, and memory recall continuum. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 208:253-265. [PMID: 34820709 DOI: 10.1007/s00359-021-01522-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 02/07/2023]
Abstract
A major extrinsic factor influencing memory and neuro-cognitive performances across taxa is diet. Studies from vertebrates have shown the effects of a flavonoid rich diet on cognitive performance, but the mechanism underlying this action is still poorly understood. A common and abundant flavonoid present in numerous food substances is quercetin (Q). The present study provides the first support for Q-modulated enhancement of cognitive function in an invertebrate model, the pond snail Lymnaea stagnalis, after an operant conditioning procedure. We found that when snails were exposed to Q 3 h before or after a single 0.5 h training session, which typically results in memory lasting ~ 3 h, they formed a long-term memory (LTM) lasting for at least 24 h. Additionally, we assessed the effects of the combined presentation of a single reinforcing stimulus (at 24 h post-training or 24 h before training) and Q-exposure on both LTM formation and reconsolidation. That is, when applied within 3 h of critical periods of memory, Q regulates four different phases: (1) acquisition (i.e., a learning event), (2) consolidation processes after acquisition, (3) memory recall, and (4) memory reconsolidation. In all these phases Q-exposure enhanced LTM persistence.
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3
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Itoh A, Komatsuzaki Y, Lukowiak K, Saito M. Epicatechin increases the persistence of long-term memory formed by conditioned taste aversion in Lymnaea. J Exp Biol 2021; 224:jeb238055. [PMID: 33443041 DOI: 10.1242/jeb.238055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022]
Abstract
We examined the effects of epicatechin (Epi), a flavonoid abundant in green tea and cocoa, on long-term memory (LTM) formed following conditioned taste aversion (CTA) training in Lymnaeastagnalis In CTA training, the snails learnt to avoid a food that initially they liked (i.e. sucrose). Twenty-four hours after CTA training, 67% of the trained snails showed a significant decrease in the feeding behaviour elicited by sucrose. Placing snails in the Epi solution in CTA training did not alter the percentage of snails exhibiting LTM, but it significantly increased LTM persistence. We also examined changes following Epi exposure in spontaneous activity of the cerebral giant cells (CGCs) that modulate feeding behaviour and are necessary for CTA-LTM. Our data suggest that Epi causes a decrease in CGC activity and increases LTM persistence, possibly via a GABAergic mechanism.
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Affiliation(s)
- Ayaka Itoh
- Department of Correlative Study in Physics and Chemistry, Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan
| | - Yoshimasa Komatsuzaki
- Department of Physics, College of Science and Technology, Nihon University, 1-8-14 Kandasurugadai, Chiyoda-ku, Tokyo 101-8308, Japan
| | - Ken Lukowiak
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, Canada T2N 4N1
| | - Minoru Saito
- Department of Correlative Study in Physics and Chemistry, Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan
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4
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PXR is a target of (-)-epicatechin in skeletal muscle. Heliyon 2020; 6:e05357. [PMID: 33163657 PMCID: PMC7610271 DOI: 10.1016/j.heliyon.2020.e05357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/21/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022] Open
Abstract
(-)-Epicatechin (EC) is a flavanol that has shown numerous biological effects such as: decrease risk of cardiovascular dysfunction, metabolism regulation, skeletal muscle (SkM) performance improvement and SkM cells differentiation induction, among others. The described EC acceptor/receptor molecules do not explain the EC's effect on SkM. We hypothesize that the pregnane X receptor (PXR) can fulfill those characteristics, based on structural similitude between EC and steroidal backbone and that PXR activation leads to similar effects as those induced by EC. In order to demonstrate our hypothesis, we: 1) analyzed the possible EC and mouse PXR interaction through in silico strategies, 2) developed an EC's affinity column to isolate PXR, 3) evaluated, in mouse myoblast (C2C12 cells) the inhibition of EC-induced PXR's nucleus translocation by ketoconazole, a specific blocker of PXR and 4) analyzed the effect of EC as an activator of mouse PXR, evaluating the expression modulation of cytochrome 3a11 (Cyp3a11) gen and myogenin protein. (-)-Epicatechin interacts and activates PXR, promoting this protein translocation to the nucleus, increasing the expression of Cyp3a11, and promoting C2C12 cell differentiation through increasing myogenin expression. These results can be the base of further studies to analyze the possible participation of PXR in the skeletal muscle effects shown by EC.
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Qu Z, Liu A, Li P, Liu C, Xiao W, Huang J, Liu Z, Zhang S. Advances in physiological functions and mechanisms of (-)-epicatechin. Crit Rev Food Sci Nutr 2020; 61:211-233. [PMID: 32090598 DOI: 10.1080/10408398.2020.1723057] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
(-)-Epicatechin (EC) is a flavanol easily obtained through the diet and is present in tea, cocoa, vegetables, fruits, and cereals. Recent studies have shown that EC protects human health and exhibits prominent anti-oxidant and anti-inflammatory activities, enhances muscle performance, improves symptoms of cardiovascular and cerebrovascular diseases, prevents diabetes, and protects the nervous system. With the development of modern medical and biotechnology research, the mechanisms of action associated with EC toward various chronic diseases are becoming more apparent, and the pharmacological development and utilization of EC has been increasingly clarified. Currently, there is no comprehensive systematic introduction to the effects of EC and its mechanisms of action. This review presents the latest research progress and the role of EC in the prevention and treatment of various chronic diseases and its protective health effects and provides a theoretical basis for future research on EC.
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Affiliation(s)
- Zhihao Qu
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Ailing Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, Hunan, China
| | - Penghui Li
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Changwei Liu
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Wenjun Xiao
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Jianan Huang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Zhonghua Liu
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Sheng Zhang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, China.,National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
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6
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Estrogenic biological activity and underlying molecular mechanisms of green tea constituents. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2019.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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7
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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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Farkhondeh T, Yazdi HS, Samarghandian S. The Protective Effects of Green Tea Catechins in the Management of Neurodegenerative Diseases: A Review. Curr Drug Discov Technol 2019; 16:57-65. [PMID: 29468975 DOI: 10.2174/1570163815666180219115453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/03/2018] [Accepted: 01/26/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND The therapeutic strategies to manage neurodegenerative diseases remain limited and it is necessary to discover new agents for their prevention and control. Oxidative stress and inflammation play a main role in the pathogenesis of neurodegenerative diseases. The aim of this study is to review the effects of green tea catechins against the Neurodegenerative Diseases. METHODS In this study, we extensively reviewed all articles on the terms of Green tea, catechins, CNS disorders, and different diseases in PubMed, Science Direct, Scopus, and Google Scholar databases between the years 1990 and 2017. RESULTS The present study found that catechins, the major flavonoids in green tea, are powerful antioxidants and radical scavengers which possess the potential roles in the management of neurodegenerative diseases. Catechins modulate the cellular and molecular mechanisms through the inflammation-related NF-κB and the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways. CONCLUSION The findings of the present review shows catechins could be effective against neurodegenerative diseases due to their antioxidation and anti-inflammation effects and the involved biochemical pathways including Nrf2 and NF-kB signaling pathways.
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Affiliation(s)
- Tahereh Farkhondeh
- Cardiovascular Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | | | - Saeed Samarghandian
- Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran
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Zhang J, de Freitas E, Lukowiak K. Black tea differs from green tea: it suppresses long-term memory formation in Lymnaea. Commun Integr Biol 2018; 11:1-4. [PMID: 30214677 PMCID: PMC6132430 DOI: 10.1080/19420889.2018.1491245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 06/13/2018] [Indexed: 11/03/2022] Open
Abstract
Foods, such as Green tea (GT), containing the flavonol, (-)-Epicatechin (Epi), enhance the formation of long-term memory (LTM) when snails are operantly conditioned in that substance. That is, a single 0.5 h training session results in LTM; whereas similar training in pond water does not result in LTM. It was of interest to determine if Black tea (BT), which is a more popular beverage than GT and which is derived from the same tea leaves, also enhances LTM formation. We found that BT, unlike GT, depressed homeostatic aerial respiratory behaviour and obstructed LTM formation. We used two different methods to determine if BT altered LTM formation and both procedures showed us that BT obstructed LTM formation. We conclude that BT obstructs LTM formation and depresses homeostatic aerial respiration
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Affiliation(s)
- Jack Zhang
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Emily de Freitas
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Strain-specific effects of crowding on long-term memory formation in Lymnaea. Comp Biochem Physiol A Mol Integr Physiol 2018; 222:43-51. [DOI: 10.1016/j.cbpa.2018.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 12/30/2022]
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11
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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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12
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Tan R, Lukowiak K. Combining Factors That Individually Enhance Memory in Lymnaea. THE BIOLOGICAL BULLETIN 2018; 234:37-44. [PMID: 29694801 DOI: 10.1086/697197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
When applied individually, thermal stress (1 hour at 30 °C) and (-)epicatechin (a flavonol found in green tea, e.g.) each enhance long-term memory formation following operant conditioning of Lymnaea aerial respiratory behavior. Snails demonstrate enhanced long-term memory formation when trained in epicatechin-treated pond water or when placed in 30 °C pond water for 1 hour, 1 hour prior to training in pond water. We ask here whether the combined application of epicatechin + thermal stress enhances long-term memory retention length beyond the maximal lengths of the individual factors alone. We report that the applied combination of epicatechin + thermal stress has a synergistic memory-enhancing effect; that is, when the two are applied in combination, memory persists longer than when either is applied alone. We then ask whether quercetin, a heat shock protein blocker, will affect the memory enhancement produced by the combined treatment of thermal stress and epicatechin. We report that quercetin does not decrease the memory enhancement of epicatechin, but it does decrease the memory enhancement by thermal stress; and it also decreases the memory persistence of snails exposed to both treatments in combination.
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Sunada H, Riaz H, de Freitas E, Lukowiak K, Swinton C, Swinton E, Protheroe A, Shymansky T, Komatsuzaki Y, Lukowiak K. Heat stress enhances LTM formation in Lymnaea: role of HSPs and DNA methylation. ACTA ACUST UNITED AC 2017; 219:1337-45. [PMID: 27208033 DOI: 10.1242/jeb.134296] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/31/2016] [Indexed: 12/30/2022]
Abstract
Environmentally relevant stressors alter the memory-forming process in Lymnaea following operant conditioning of aerial respiration. One such stressor is heat. Previously, we found that following a 1 h heat shock, long-term memory (LTM) formation was enhanced. We also had shown that the heat stressor activates at least two heat shock proteins (HSPs): HSP40 and HSP70. Here, we tested two hypotheses: (1) the production of HSPs is necessary for enhanced LTM formation; and (2) blocking DNA methylation prevents the heat stressor-induced enhancement of LTM formation. We show here that the enhancing effect of the heat stressor on LTM formation occurs even if snails experienced the stressor 3 days previously. We further show that a flavonoid, quercetin, which inhibits HSP activation, blocks the enhancing effect of the heat stressor on LTM formation. Finally, we show that injection of a DNA methylation blocker, 5-AZA, before snails experience the heat stressor prevents enhancement of memory formation.
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Affiliation(s)
- Hiroshi Sunada
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Hamza Riaz
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Emily de Freitas
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Kai Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Cayley Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Erin Swinton
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Amy Protheroe
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Tamila Shymansky
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Yoshimasa Komatsuzaki
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Ken Lukowiak
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
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Fernell M, Swinton C, Lukowiak K. Epicatechin, a component of dark chocolate, enhances memory formation if applied during the memory consolidation period. Commun Integr Biol 2016; 9:e1205772. [PMID: 27574544 PMCID: PMC4988431 DOI: 10.1080/19420889.2016.1205772] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 06/17/2016] [Accepted: 06/17/2016] [Indexed: 01/15/2023] Open
Abstract
Epicatechin (Epi), a flavanol found in foods such as dark chocolate has previously been shown to enhance memory formation in our model system, operant conditioning of aerial respiration in Lymnaea. In those experiments snails were trained in Epi. Here we ask whether snails exposed to Epi before training, during the consolidation period immediately following training, or 1 h after training would enhance memory formation. We report here that Epi is only able to enhance memory if snails are placed in Epi-containing pond water immediately after training. That is, Epi enhances memory formation if it is applied during the memory consolidation period as well as if snails are trained in Epi-containing pond water.
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Affiliation(s)
- Maria Fernell
- Hotchkiss Brain Institute Cumming School of Medicine, University of Calgary , Calgary, AB, Canada
| | - Cayley Swinton
- Hotchkiss Brain Institute Cumming School of Medicine, University of Calgary , Calgary, AB, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute Cumming School of Medicine, University of Calgary , Calgary, AB, Canada
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15
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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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