Caenorhabditis elegans Learning and Memory

2019 ◽  
Author(s):  
James S.H. Wong ◽  
Catharine H. Rankin
Keyword(s):  
Carbon Dioxide ◽  
Caenorhabditis Elegans ◽  
Classical Conditioning ◽  
Learning And Memory ◽  
Long Term Memory ◽  
Context Conditioning ◽  
Term Memory ◽  
C Elegans

The nematode, Caenorhabditis elegans (C. elegans), is an organism useful for the study of learning and memory at the molecular, cellular, neural circuitry, and behavioral levels. Its genetic tractability, transparency, connectome, and accessibility for in vivo cellular and molecular analyses are a few of the characteristics that make the organism such a powerful system for investigating mechanisms of learning and memory. It is able to learn and remember across many sensory modalities, including mechanosensation, chemosensation, thermosensation, oxygen sensing, and carbon dioxide sensing. C. elegans habituates to mechanosensory stimuli, and shows short-, intermediate-, and long-term memory, and context conditioning for mechanosensory habituation. The organism also displays chemotaxis to various chemicals, such as diacetyl and sodium chloride. This behavior is associated with several forms of learning, including state-dependent learning, classical conditioning, and aversive learning. C. elegans also shows thermotactic learning in which it learns to associate a particular temperature with the presence or absence of food. In addition, both oxygen preference and carbon dioxide avoidance in C. elegans can be altered by experience, indicating that they have memory for the oxygen or carbon dioxide environment they were reared in. Many of the genes found to underlie learning and memory in C. elegans are homologous to genes involved in learning and memory in mammals; two examples are crh-1, which is the C. elegans homolog of the cAMP response element-binding protein (CREB), and glr-1, which encodes an AMPA glutamate receptor subunit. Both of these genes are involved in long-term memory for tap habituation, context conditioning in tap habituation, and chemosensory classical conditioning. C. elegans offers the advantage of having a very small nervous system (302 neurons), thus it is possible to understand what these conserved genes are doing at the level of single identified neurons. As many mechanisms of learning and memory in C. elegans appear to be similar in more complex organisms including humans, research with C. elegans aids our ever-growing understanding of the fundamental mechanisms of learning and memory across the animal kingdom.

scholarly journals Soft-wired long-term memory in a natural recurrent neuronal network

2020 ◽  
Author(s):  
Miguel A. Casal ◽  
Santiago Galella ◽  
Oscar Vilarroya ◽  
Jordi Garcia-Ojalvo
Keyword(s):  
Neuronal Network ◽  
Neuronal Networks ◽  
Initial Conditions ◽  
Permutation Entropy ◽  
Long Term Memory ◽  
Term Memory ◽  
C Elegans ◽  
Living Organisms ◽  
Recurrent Connections

Neuronal networks provide living organisms with the ability to process information. They are also characterized by abundant recurrent connections, which give rise to strong feed-back that dictates their dynamics and endows them with fading (short-term) memory. The role of recurrence in long-term memory, on the other hand, is still unclear. Here we use the neuronal network of the roundworm C. elegans to show that recurrent architectures in living organisms can exhibit long-term memory without relying on specific hard-wired modules. A genetic algorithm reveals that the experimentally observed dynamics of the worm’s neuronal network exhibits maximal complexity (as measured by permutation entropy). In that complex regime, the response of the system to repeated presentations of a time-varying stimulus reveals a consistent behavior that can be interpreted as soft-wired long-term memory.A common manifestation of our ability to remember the past is the consistence of our responses to repeated presentations of stimuli across time. Complex chaotic dynamics is known to produce such reliable responses in spite of its characteristic sensitive dependence on initial conditions. In neuronal networks, complex behavior is known to result from a combination of (i) recurrent connections and (ii) a balance between excitation and inhibition. Here we show that those features concur in the neuronal network of a living organism, namely C. elegans. This enables long-term memory to arise in an on-line manner, without having to be hard-wired in the brain.

scholarly journals Effects of Pramipexole on Learning and Memory Processes in Naïve and Haloperidol-challenged Rats in Active Avoidance Test

Folia Medica ◽  
2019 ◽  
Vol 61 (2) ◽  
pp. 258-265 ◽  
Author(s):  
Anita S. Mihaylova ◽  
Ilia D. Kostadinov ◽  
Nina D. Doncheva ◽  
Hristina I. Zlatanova ◽  
Delian P. Delev
Keyword(s):  
Learning And Memory ◽  
Active Avoidance ◽  
Memory Test ◽  
Long Term Memory ◽  
Motor Symptoms ◽  
Term Memory ◽  
Avoidance Test ◽  
Male Wistar Rats ◽  
Active Avoidance Test

Abstract Background: Parkinson’s disease (PD) is the second most common neurode-generative disease, usually detected by its motor symptoms. The non-motor symptoms, including cognitive deficits, have been of great interest to researchers in the last few decades. Aim: To assess the effect of pramipexole on learning and memory in naïve and haloperidol-challenged rats. Materials and methods: Male Wistar rats divided into 9 groups (n=8): naïve - saline, pramipexole 0.5; 1 and 3 mg/kg bw; Haloperidol groups - saline, haloperidol, haloperidol + pramipexole 0.5; 1 and 3 mg/kg bw. Two-way active avoidance test (TWAA) and activity cage were performed. The studied parameters were: number of conditioned and unconditioned responses, vertical and horizontal movements. Statistical analysis was done using SPSS 19. Results: The naïve experimental groups significantly increased the number of conditioned responses during the tests for short- and long-term memory, compared with the saline groups (p<0.05). During the short-memory test only the animals with the lowest dose of PMX significantly increased the number of unconditioned responses whereas during the long-term memory test all experimental groups increased the number of escapes in comparison with the saline groups (p<0.05). Challenge dose of haloperidol attenuates learning and memory in pramipexol treated rats. Only the highest dose of pramipexol showed significant increase in conditioned and unconditioned responses compared with the haloperidol group (p<0.05). Conclusion: Pramipexole improves learning and memory in naïve rats by enhancing dopaminergic neurotransmission. This is probably not the only mechanism involved. This is confirmed by the decrease in learning and memory ability in rats with haloperidol-challenge.

scholarly journals Persistence of Long-Term Memory in Vitrified and Revived Caenorhabditis elegans

2015 ◽  
Vol 18 (5) ◽  
pp. 458-463 ◽  
Author(s):  
Natasha Vita-More ◽  
Daniel Barranco
Keyword(s):  
Caenorhabditis Elegans ◽  
Long Term Memory ◽  
Term Memory

scholarly journals Effect of a composite mixture of native and oligomeric forms of the α-synuclein protein upon intranasal administration on aging mouse behavior

2018 ◽  
pp. 51-57
Author(s):  
О.А. Соловьева ◽  
М.А. Грудень ◽  
И.А. Калинин ◽  
А.М. Ратмиров ◽  
В.В. Шерстнев
Keyword(s):  
Motor Activity ◽  
Lewy Bodies ◽  
Behavioral Effects ◽  
Long Term Memory ◽  
Term Memory ◽  
Composite Mixture ◽  
Oligomeric Forms

Одним из важнейших патогенетических звеньев развития синуклеинопатий - группы хронических нейродегенеративных заболеваний, таких как болезнь Паркинсона, деменции с тельцами Леви и других является гиперпродукция белка α-синуклеина с последующей его агрегацией и образованием различающихся по размеру и структуре амилоидогенных форм белка, которые инициируют гибель нервных или глиальных клеток. В настоящее время для более полного понимания происходящих in vivo патологических процессов актуально изучение на моделях животных поведенческих эффектов как нативного белка α-синуклеина, так и его отдельных амилоидогенных структур (олигомеров и фибрилл), полученных и охарактеризованных in vitro, а также композиционных смесей данных белковых конформаций. Целью данной работы явилось изучение влияния композиционной смеси нативного белка α-синуклеина и олигомеров α-синуклеина при хроническом интраназальном введении на двигательную активность, кратковременную и долговременную память, а также тревожность стареющих мышей. Методы. Опыты проводили на 12- месячных самцах мышей C57Bl/6, которым на протяжении 14 дней один раз в сутки вводили отдельно в каждую ноздрю раствор α-синуклеина и его олигомеров, либо физиологический раствор. В тестах «Открытое поле», «Распознавание нового объекта», «Условная реакция пассивного избегания» и «Приподнятый крестообразный лабиринт» оценивали двигательную активность, кратко- и долговременную память, и тревожность животных. Результаты. Показано, что исследованная композиционная смесь конформаций α-синуклеина не вызывает статистически значимых изменений регистрируемых поведенческих показателей у стареющих мышей. Вместе с тем, ранее нами было документировано, что в условиях аналогичного экспериментального протокола нативный α-синуклеин инициирует снижение двигательной активности, а олигомеры α-синуклеина - угнетение двигательной активности, нарушение долговременной памяти и тревожности животных. Заключение. Полученные результаты свидетельствуют о менее выраженных поведенческих эффектах композиционной смеси нативной и олигомерной форм α-синуклеина, по сравнению с отдельными ее компонентами. Рассматриваются возможные механизмы выявленных особенностей влияния исследованной композиционной смеси конформаций α-синуклеина на поведенческом уровне. One of the most important steps in the pathogenesis of synucleinopathies, a group of chronic neurodegenerative diseases, such as Parkinson’s disease, dementia with Lewy bodies and others, is overproduction of α-synuclein protein, followed by its aggregation and formation of amyloidogenic protein species, which differ in their size and structure and initiate death of nerve or glial cells. At present, better understanding of in vivo pathological processes requires studying behavioral effects of both the native α-synuclein protein and its individual amyloidogenic structures (oligomers and fibrils) obtained and characterized in vitro on animal models, as well as composite mixtures of these protein conformations. The aim of this work was to study effects of chronic nasal application of a composite mixture of native α-synuclein protein and α-synuclein oligomers on motor activity, short-term and long-term memory, and anxiety of aging mice. Methods. Experiments were carried out on 12-month old male C57Bl/6 mice, which received a solution of α-synuclein and its oligomers or a saline solution separately into each nostril for 14 days daily. Motor activity, short- and long-term memory and anxiety of animals were evaluated in Open Field, Novel Object Recognition, Conditioned Passive Avoidance, and Elevated Plus Maze tests. Results. The studied composite mixture of α-synuclein conformations did not induce statistically significant changes in behavioral indices of aging mice. At the same time, we have previously documented that in a similar experimental protocol, native α-synuclein initiates a decrease in motor activity, and α-synuclein oligomers - inhibition of motor activity and disorders of long-term memory and anxiety. Conclusion. The results indicated less pronounced behavioral effects of the composite mixture of native and oligomeric forms of α-synuclein compared with its individual components. The authors discussed possible mechanisms of the behavioral effects of the studied composite mixture of α-synuclein confirmations.

scholarly journals Endophilin A1 drives acute structural plasticity of dendritic spines in response to Ca2+/calmodulin

2021 ◽  
Vol 220 (6) ◽  
Author(s):  
Yanrui Yang ◽  
Jiang Chen ◽  
Xue Chen ◽  
Di Li ◽  
Jianfeng He ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Dendritic Spines ◽  
Actin Polymerization ◽  
Structural Plasticity ◽  
Long Term Potentiation ◽  
Membrane Dynamics ◽  
Long Term Memory ◽  
Term Memory ◽  
Term Potentiation

Induction of long-term potentiation (LTP) in excitatory neurons triggers a large transient increase in the volume of dendritic spines followed by decays to sustained size expansion, a process termed structural LTP (sLTP) that contributes to the cellular basis of learning and memory. Although mechanisms regulating the early and sustained phases of sLTP have been studied intensively, how the acute spine enlargement immediately after LTP stimulation is achieved remains elusive. Here, we report that endophilin A1 orchestrates membrane dynamics with actin polymerization to initiate spine enlargement in NMDAR-mediated LTP. Upon LTP induction, Ca2+/calmodulin enhances binding of endophilin A1 to both membrane and p140Cap, a cytoskeletal regulator. Consequently, endophilin A1 rapidly localizes to the plasma membrane and recruits p140Cap to promote local actin polymerization, leading to spine head expansion. Moreover, its molecular functions in activity-induced rapid spine growth are required for LTP and long-term memory. Thus, endophilin A1 serves as a calmodulin effector to drive acute structural plasticity necessary for learning and memory.

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