scholarly journals Reinstatement of long-term memory following erasure of its behavioral and synaptic expression in Aplysia

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Shanping Chen ◽  
Diancai Cai ◽  
Kaycey Pearce ◽  
Philip Y-W Sun ◽  
Adam C Roberts ◽  
...  

Long-term memory (LTM) is believed to be stored in the brain as changes in synaptic connections. Here, we show that LTM storage and synaptic change can be dissociated. Cocultures of Aplysia sensory and motor neurons were trained with spaced pulses of serotonin, which induces long-term facilitation. Serotonin (5HT) triggered growth of new presynaptic varicosities, a synaptic mechanism of long-term sensitization. Following 5HT training, two antimnemonic treatments—reconsolidation blockade and inhibition of PKM—caused the number of presynaptic varicosities to revert to the original, pretraining value. Surprisingly, the final synaptic structure was not achieved by targeted retraction of the 5HT-induced varicosities but, rather, by an apparently arbitrary retraction of both 5HT-induced and original synapses. In addition, we find evidence that the LTM for sensitization persists covertly after its apparent elimination by the same antimnemonic treatments that erase learning-related synaptic growth. These results challenge the idea that stable synapses store long-term memories.

1992 ◽  
Vol 119 (5) ◽  
pp. 1069-1076 ◽  
Author(s):  
D Kuhl ◽  
T E Kennedy ◽  
A Barzilai ◽  
E R Kandel

Long-term memory for sensitization of the gill- and siphon-withdrawal reflexes in Aplysia californica requires RNA and protein synthesis. These long-term behavioral changes are accompanied by long-term facilitation of the synaptic connections between the gill and siphon sensory and motor neurons, which are similarly dependent on transcription and translation. In addition to showing an increase in over-all protein synthesis, long-term facilitation is associated with changes in the expression of specific early, intermediate, and late proteins, and with the growth of new synaptic connections between the sensory and motor neurons of the reflex. We previously focused on early proteins and have identified four proteins as members of the immunoglobulin family of cell adhesion molecules related to NCAM and fasciclin II. We have now cloned the cDNA corresponding to one of the late proteins, and identified it as the Aplysia homolog of BiP, an ER resident protein involved in the folding and assembly of secretory and membrane proteins. Behavioral training increases the steady-state level of BiP mRNA in the sensory neurons. The increase in the synthesis of BiP protein is first detected 3 h after the onset of facilitation, when the increase in overall protein synthesis reaches its peak and the formation of new synaptic terminals becomes apparent. These findings suggest that the chaperon function of BiP might serve to fold proteins and assemble protein complexes necessary for the structural changes characteristic of long-term memory.


1999 ◽  
Vol 77 (9) ◽  
pp. 738-747 ◽  
Author(s):  
Craig H Bailey

Long-term memory for sensitization of the gill-withdrawal reflex inAplysia is associated with the growth of new synaptic connections between sensory and motor neurons. The duration of this structural change parallels the behavioral retention of the memory. Such changes can be reconstituted in dissociated cell culture by repeated presentations of the modulatory neurotransmitter serotonin (5HT) and are associated with an activity-dependent downregulation of NCAM-related cell adhesion molecules thought to contribute to cell recognition and axonal outgrowth during development. Thus, aspects of the mechanisms utilized for learning-related synaptic growth initiated by experience in the adult may eventually be understood in the context of the molecular logic that shapes synaptic circuitry during the later stages of neuronal development.Key words: learning, synapse, invertebrate, habituation, sensitization.


2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.


Author(s):  
Kinga K. Borowicz-Reutt ◽  
Monika Banach ◽  
Monika Rudkowska ◽  
Anna Stachniuk

Abstract Background Due to blocking β-receptors, and potassium KCNH2 channels, sotalol may influence seizure phenomena. In the previous study, we have shown that sotalol potentiated the antielectroshock action of phenytoin and valproate in mice. Materials and methods As a continuation of previous experiments, we examined the effect of sotalol on the action of four chosen second-generation antiepileptic drugs (oxcarbazepine, lamotrigine, pregabalin, and topiramate) against the maximal electroshock in mice. Undesired effects were evaluated in the chimney test (motor impairment) and step-through passive-avoidance task (long-term memory deficits). Finally, brain concentrations of antiepileptics were determined by fluorescence polarization immunoassay, while those of sotalol by liquid chromatography–mass spectrometry. Results Sotalol at doses of up to 100 mg/kg did not affect the electroconvulsive threshold. Applied at doses of 80–100 mg/kg, sotalol did not affect the antielectroshock action of oxcarbazepine, lamotrigine, pregabalin, or topiramate. Sotalol alone and in combinations with antiepileptics impaired neither motor performance nor long-term memory. Finally, sotalol significantly decreased the brain concentrations of lamotrigine and increased those of oxcarbazepine and topiramate. Pharmacokinetic interactions, however, did not influence the final antielectroshock effects of above-mentioned drug combinations. On the other hand, the brain concentrations of sotalol were not changed by second-generation antiepileptics used in this study. Conclusion Sotalol did not reduce the antielectroshock action of four second-generation antiepileptic drugs examined in this study. Therefore, this antidepressant drug should not interfere with antiseizure effects of lamotrigine, oxcarbazepine, pregabalin, and topiramate in patients with epilepsy. To draw final conclusions, our preclinical data should still be confirmed in other experimental models and clinical conditions.


2020 ◽  
Vol 43 (1) ◽  
pp. 297-314 ◽  
Author(s):  
Josué Haubrich ◽  
Matteo Bernabo ◽  
Andrew G. Baker ◽  
Karim Nader

An enduring problem in neuroscience is determining whether cases of amnesia result from eradication of the memory trace (storage impairment) or if the trace is present but inaccessible (retrieval impairment). The most direct approach to resolving this question is to quantify changes in the brain mechanisms of long-term memory (BM-LTM). This approach argues that if the amnesia is due to a retrieval failure, BM-LTM should remain at levels comparable to trained, unimpaired animals. Conversely, if memories are erased, BM-LTM should be reduced to resemble untrained levels. Here we review the use of BM-LTM in a number of studies that induced amnesia by targeting memory maintenance or reconsolidation. The literature strongly suggests that such amnesia is due to storage rather than retrieval impairments. We also describe the shortcomings of the purely behavioral protocol that purports to show recovery from amnesia as a method of understanding the nature of amnesia.


Author(s):  
Mathias Scharinger ◽  
William J. Idsardi ◽  
Samantha Poe

AbstractVowel harmony is a phonotactic principle that requires adjacent vowels to agree in certain vowel features. Phonological theory considers this principle to be represented in one's native grammar, but its abstractness and perceptual consequences remain a matter of debate. In this paper, we are interested in the brain's response to violations of harmony in Turkish. For this purpose, we test two acoustically close and two acoustically distant vowel pairs in Turkish, involving different kinds of harmony violations. Our measure is the Mismatch Negativity (MMN), an automatic change detection response of the brain that has previously been applied for the study of native phoneme representations in a variety of languages. The results of our experiment support the view that vowel harmony is a phonological principle with a language-specific long-term memory representation. Asymmetries in MMN responses support a phonological analysis of the pattern of results, but do not provide evidence for a pure acoustic or a pure probabilistic approach. Phonological analyses are given within Optimality Theory (OT) and within an underspecification account.


Author(s):  
Lia Almeida Mapurunga ◽  
Elcyana Bezerra Elcyana Bezerra Carvalho

A neurociência é uma ciência natural que estuda a função e a estrutura, que compõem o cérebro. A educação, embora tenha outra natureza, tem tido muitos benefícios com as contribuições que a neurociência tem para oferecer. Como o cérebro aprende e por que aprende traz para o ensino o objetivo e a função de criar condições (entre estratégias, recursos e adequação do meio), para que ocorra a aprendizagem. E, para que essa ocorra, é necessário que as funções mentais superiores, como a memória, estejam envolvidas. O objetivo deste estudo consiste em fazer uma revisão de literatura para conhecer a função da memória de longo prazo na aprendizagem, analisar os mecanismos neurobiológicos, que ocorrem durante esse processo e algumas estratégias de aprendizagem, que se utilizam da memória como recurso. Para isso, foi realizado no período de agosto a outubro de 2016, um levantamento bibliográfico nas bases de dados Scielo, Capes, Bireme e Google Acadêmico, buscando artigos científicos, que poderiam trazer alguma contribuição na construção dessa pesquisa. Foram selecionados, preferencialmente, os que continham enfoque na relação entre aprendizagem e memória, tanto na perspectiva da neurociência, quanto da psicologia cognitiva, trazendo argumentos que pudessem  comprovar o entendimento das estratégias de aprendizagem, a partir da memória de longo prazo. Também foram selecionados livros que apresentavam apoio às temáticas discorridas para esse trabalho, possibilitando essa relação. Os resultados apontam que estratégias de aprendizagens, que utilizam a memória, produzem efeitos positivos para a retenção de longo prazo.Palavras-chave: Aprendizagem. Neurociências. Estratégias de Aprendizagem.AbstractNeuroscience is a natural science that studies the function and structure that forms the brain. Although education has another nature, it has had many benefits from the contributions that neuroscience has to offer. How the brain learns and why it learns brings to teaching the intent and function to create conditions (among strategies, resources and suitability to the environment) so that learning can happen. And, for it to occur, it is  necessary that higher mental functions, such as memory, beinvolved. The purpose of this study is to do a literature review to get to know the function of long-term memory on the learning process, to analyze the neurobiological mechanisms that happen during that process, and some learning strategies that use memory as a resource. Therefore a bibliographical survey was conducted at the databases Scielo, Capes, Bireme and Academic Google, from August to October 2016, searching for scientific articles that could contribute somehow on the construction of this research. The articles that used the neuroscience perspective or the cognitive psychology to focus on the relationship  between learning and memory were chosen, preferentially those whose arguments could prove the  learning strategies understanding about he long-term memory. Books supporting the themes discussed for this work were also selected, creating, therefore, a relationship. The results show that learning strategies that use memory have positive effects for long-term retention.Keywords: Learning. Neuroscience. Learning Strategies.


SIMULATION ◽  
1964 ◽  
Vol 3 (6) ◽  
pp. 46-51
Author(s):  
W. Ross Adey ◽  
N.V. Findler

It is attempted in this paper to give a mathematical description of the short-term memory. Instead of using the microscopic properties of individual neu rons, such as the number of interconnections, neuron density, threshold value, etc., the cerebral cortex is regarded as a "neuron gas" that is a vast conglomer ate of neurons with statistically distributed charac teristics. Stimuli from the environment cause the receptor neurons to emit virtual electromagnetic waves into the brain. A self-optimizing process of the brain tis sue is here described by which the useful, informa tion-carrying energy reaching the long-term memory tends to maximum. It is emphasized that in the following a brain model is described and the physical processes in volved may have no direct equivalent in reality.


1999 ◽  
Vol 31 (3) ◽  
pp. 261-274 ◽  
Author(s):  
Selene Cansino ◽  
Alejandra Ruiz ◽  
Verónica López-Alonso

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