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Eric R. Kandel - One of the best experts on this subject based on the ideXlab platform.
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Presynaptic and Postsynaptic Mechanisms of Synaptic Plasticity and Metaplasticity during Intermediate-Term Memory Formation in Aplysia
The Journal of Neuroscience, 2010Co-Authors: Igor Antonov, Eric R. Kandel, Robert D. HawkinsAbstract:Synaptic plasticity and learning involve different mechanisms depending on the following: (1) the stage of plasticity and (2) the history of plasticity, or metaplasticity. However, little is known about how these two factors are related. We have addressed that question by examining mechanisms of synaptic plasticity during short-term and intermediate-term behavioral sensitization and Dishabituation in a semi-intact preparation of the Aplysia siphon-withdrawal reflex. Dishabituation differs from sensitization in that it is preceded by habituation, and is thus a paradigm for metaplasticity. We find that whereas facilitation during short-term sensitization by one tail shock involves presynaptic covalent modifications by protein kinase A (PKA) and CamKII, facilitation during intermediate-term sensitization by four shocks involves both presynaptic (PKA, CaMKII) and postsynaptic (Ca2+, CaMKII) covalent modifications, as well as both presynaptic and postsynaptic protein synthesis. The facilitation also involves presynaptic spike broadening 2.5 min after either one or four shocks, but not at later times. Dishabituation by four shocks differs from sensitization in several ways. First, it does not involve PKA or CaMKII, but rather involves presynaptic PKC. In addition, unlike sensitization with the same shock, Dishabituation by four shocks does not involve protein synthesis or presynaptic spike broadening, and it also does not involve postsynaptic Ca2+. These results demonstrate that not only the mechanisms but also the site of plasticity depend on both the stage of plasticity and metaplasticity during memory formation.
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Dishabituation in Aplysia can involve either reversal of habituation or superimposed sensitization.
Learning & memory (Cold Spring Harbor N.Y.), 2006Co-Authors: Robert D. Hawkins, Tracey E. Cohen, Eric R. KandelAbstract:Dishabituation has been thought to be due either to reversal of the process of habituation or to a second process equivalent to sensitization superimposed on habituation. One way to address this question is by testing whether Dishabituation and sensitization can be dissociated. Previous studies using this approach in Aplysia have come to different conclusions about the nature of Dishabituation, perhaps because those studies differed in many respects, including (1) whether they also observed transient behavioral inhibition, and (2) whether they used test stimuli that activated the LE siphon sensory neurons or as yet unidentified sensory neurons. To attempt to resolve the apparent contradictions between the previous studies, we have explored the importance of these two factors by performing a parametric study of Dishabituation and sensitization of gill withdrawal in a simplified preparation that does not exhibit transient behavioral inhibition, using two different test stimuli that are known to activate the LE (Touch) or unidentified (Not Touch) sensory neurons. We find that Dishabituation and sensitization in this preparation have similar time courses and generally similar functions of shock intensity. However, under one condition, with the Not Touch stimulus 2.5 min after the shock, Dishabituation has a reverse effect of shock intensity. Additional analyses suggest that Dishabituation with the Not Touch stimulus 2.5 min after the shock is due to reversal of habituation, whereas 12.5 min after the shock, Dishabituation is due to superimposed sensitization. These results thus suggest that Dishabituation may involve either process in the same preparation, and begin to define the conditions that favor one or the other.
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the contribution of facilitation of monosynaptic psps to Dishabituation and sensitization of the aplysia siphon withdrawal reflex
The Journal of Neuroscience, 1999Co-Authors: Igor Antonov, Eric R. Kandel, Robert D. HawkinsAbstract:To examine the relationship between synaptic plasticity and learning and memory as directly as possible, we have developed a new simplified preparation for studying the siphonwithdrawal reflex of Aplysia in which it is relatively easy to record synaptic connections between individual identified neurons during simple forms of learning. We estimated that monosynaptic EPSPs from LE siphon sensory neurons to LFS siphon motor neurons mediate approximately one-third of the reflex response measured in this preparation, which corresponds to siphon flaring in the intact animal. To investigate cellular mechanisms contributing to Dishabituation and sensitization, we recorded evoked firing of LFS neurons, the siphon withdrawal produced by stimulation of an LFS neuron, the complex PSP in an LFS neuron, and the monosynaptic PSP from an “on-field” or “off-field” LE neuron to an LFS neuron during behavioral training. Unlike the simplified gill-withdrawal preparation (Cohen et al., 1997; Frost et al., 1997), in the siphon-withdrawal preparation we found no qualitative differences between the major cellular mechanisms contributing to Dishabituation and sensitization, suggesting that dissociations that have been observed previously may be attributable to transient inhibition that does not occur for this component of the reflex. Furthermore, in the siphon-withdrawal preparation, all of the various cellular measures, including monosynaptic PSPs from either on-field or off-field LE neurons, changed approximately in parallel with changes in the behavior. These results provide the most direct evidence so far available that both Dishabituation and sensitization involve multiple mechanisms, including heterosynaptic facilitation of sensory neuron-motor neuron PSPs.
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relationships between Dishabituation sensitization and inhibition of the gill and siphon withdrawal reflex in aplysia californica effects of response measure test time and training stimulus
Behavioral Neuroscience, 1998Co-Authors: Robert D. Hawkins, Tracey E. Cohen, Winifred Greene, Eric R. KandelAbstract:Previous studies have raised questions about the relationships between habituation, Dishabituation, sensitization, and inhibition of reflex responses. To explore this issue further, a systematic study of these simple forms of learning was carried out in unrestrained Aplysia in which the amplitude as well as the duration of both the gill- and siphon-withdrawal reflexes were measured after either tailshock or mantle shock. The results suggest that transient reflex inhibition is not an invariant effect of noxious stimulation but depends instead on the response measure, test time, and type of noxious stimulus. Furthermore, the results suggest that Dishabituation and sensitization may not involve different processes at the behavioral level; rather the observed differences between them may be due largely to an interaction between habituation and inhibition.
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a simplified preparation for relating cellular events to behavior contribution of le and unidentified siphon sensory neurons to mediation and habituation of the aplysia gill and siphon withdrawal reflex
The Journal of Neuroscience, 1997Co-Authors: Lina Frost, Eric R. Kandel, Tracey E. Cohen, Saul W Kaplan, Victor Henzi, Robert D. HawkinsAbstract:We have begun to analyze several elementary forms of learning in a simple preparation consisting of the isolated mantle organs and abdominal ganglion of Aplysia. Previous studies suggested that plasticity at siphon sensory neuron synapses contributes to habituation and Dishabituation of the gill- and siphon-withdrawal reflex in this preparation. We next wished to identify the sensory neurons that participate in the reflex and examine their plasticity more directly. To investigate the contribution of the LE siphon mechanosensory cells, we recorded from them and gill or siphon motor neurons during the same siphon stimulation that has been used in behavioral experiments in this preparation. Our results indicate that the LE cells make a substantial contribution to the evoked response in the motor neurons under these conditions, but they suggest that other as yet unidentified siphon sensory neurons with lower thresholds and shorter latencies also contribute. In addition, we find that homosynaptic depression of monosynaptic postsynaptic potentials (PSPs) from LE sensory cells makes an important contribution to habituation of the response in the motor neurons. To investigate plasticity of PSPs from the unidentified sensory neurons, we recorded the PSP that was produced in a motor neuron by water-movement stimulation of the siphon, which does not cause firing of LE cells. Our results suggest that PSPs from the unidentified sensory neurons and the LE neurons undergo similar plasticity during habituation and Dishabituation training. These results support the idea that plasticity at synapses of both LE and unidentified sensory neurons contributes to habituation and Dishabituation of the reflex response in this preparation.
Robert D. Hawkins - One of the best experts on this subject based on the ideXlab platform.
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Presynaptic and Postsynaptic Mechanisms of Synaptic Plasticity and Metaplasticity during Intermediate-Term Memory Formation in Aplysia
The Journal of Neuroscience, 2010Co-Authors: Igor Antonov, Eric R. Kandel, Robert D. HawkinsAbstract:Synaptic plasticity and learning involve different mechanisms depending on the following: (1) the stage of plasticity and (2) the history of plasticity, or metaplasticity. However, little is known about how these two factors are related. We have addressed that question by examining mechanisms of synaptic plasticity during short-term and intermediate-term behavioral sensitization and Dishabituation in a semi-intact preparation of the Aplysia siphon-withdrawal reflex. Dishabituation differs from sensitization in that it is preceded by habituation, and is thus a paradigm for metaplasticity. We find that whereas facilitation during short-term sensitization by one tail shock involves presynaptic covalent modifications by protein kinase A (PKA) and CamKII, facilitation during intermediate-term sensitization by four shocks involves both presynaptic (PKA, CaMKII) and postsynaptic (Ca2+, CaMKII) covalent modifications, as well as both presynaptic and postsynaptic protein synthesis. The facilitation also involves presynaptic spike broadening 2.5 min after either one or four shocks, but not at later times. Dishabituation by four shocks differs from sensitization in several ways. First, it does not involve PKA or CaMKII, but rather involves presynaptic PKC. In addition, unlike sensitization with the same shock, Dishabituation by four shocks does not involve protein synthesis or presynaptic spike broadening, and it also does not involve postsynaptic Ca2+. These results demonstrate that not only the mechanisms but also the site of plasticity depend on both the stage of plasticity and metaplasticity during memory formation.
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Dishabituation in Aplysia can involve either reversal of habituation or superimposed sensitization.
Learning & memory (Cold Spring Harbor N.Y.), 2006Co-Authors: Robert D. Hawkins, Tracey E. Cohen, Eric R. KandelAbstract:Dishabituation has been thought to be due either to reversal of the process of habituation or to a second process equivalent to sensitization superimposed on habituation. One way to address this question is by testing whether Dishabituation and sensitization can be dissociated. Previous studies using this approach in Aplysia have come to different conclusions about the nature of Dishabituation, perhaps because those studies differed in many respects, including (1) whether they also observed transient behavioral inhibition, and (2) whether they used test stimuli that activated the LE siphon sensory neurons or as yet unidentified sensory neurons. To attempt to resolve the apparent contradictions between the previous studies, we have explored the importance of these two factors by performing a parametric study of Dishabituation and sensitization of gill withdrawal in a simplified preparation that does not exhibit transient behavioral inhibition, using two different test stimuli that are known to activate the LE (Touch) or unidentified (Not Touch) sensory neurons. We find that Dishabituation and sensitization in this preparation have similar time courses and generally similar functions of shock intensity. However, under one condition, with the Not Touch stimulus 2.5 min after the shock, Dishabituation has a reverse effect of shock intensity. Additional analyses suggest that Dishabituation with the Not Touch stimulus 2.5 min after the shock is due to reversal of habituation, whereas 12.5 min after the shock, Dishabituation is due to superimposed sensitization. These results thus suggest that Dishabituation may involve either process in the same preparation, and begin to define the conditions that favor one or the other.
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the contribution of facilitation of monosynaptic psps to Dishabituation and sensitization of the aplysia siphon withdrawal reflex
The Journal of Neuroscience, 1999Co-Authors: Igor Antonov, Eric R. Kandel, Robert D. HawkinsAbstract:To examine the relationship between synaptic plasticity and learning and memory as directly as possible, we have developed a new simplified preparation for studying the siphonwithdrawal reflex of Aplysia in which it is relatively easy to record synaptic connections between individual identified neurons during simple forms of learning. We estimated that monosynaptic EPSPs from LE siphon sensory neurons to LFS siphon motor neurons mediate approximately one-third of the reflex response measured in this preparation, which corresponds to siphon flaring in the intact animal. To investigate cellular mechanisms contributing to Dishabituation and sensitization, we recorded evoked firing of LFS neurons, the siphon withdrawal produced by stimulation of an LFS neuron, the complex PSP in an LFS neuron, and the monosynaptic PSP from an “on-field” or “off-field” LE neuron to an LFS neuron during behavioral training. Unlike the simplified gill-withdrawal preparation (Cohen et al., 1997; Frost et al., 1997), in the siphon-withdrawal preparation we found no qualitative differences between the major cellular mechanisms contributing to Dishabituation and sensitization, suggesting that dissociations that have been observed previously may be attributable to transient inhibition that does not occur for this component of the reflex. Furthermore, in the siphon-withdrawal preparation, all of the various cellular measures, including monosynaptic PSPs from either on-field or off-field LE neurons, changed approximately in parallel with changes in the behavior. These results provide the most direct evidence so far available that both Dishabituation and sensitization involve multiple mechanisms, including heterosynaptic facilitation of sensory neuron-motor neuron PSPs.
-
relationships between Dishabituation sensitization and inhibition of the gill and siphon withdrawal reflex in aplysia californica effects of response measure test time and training stimulus
Behavioral Neuroscience, 1998Co-Authors: Robert D. Hawkins, Tracey E. Cohen, Winifred Greene, Eric R. KandelAbstract:Previous studies have raised questions about the relationships between habituation, Dishabituation, sensitization, and inhibition of reflex responses. To explore this issue further, a systematic study of these simple forms of learning was carried out in unrestrained Aplysia in which the amplitude as well as the duration of both the gill- and siphon-withdrawal reflexes were measured after either tailshock or mantle shock. The results suggest that transient reflex inhibition is not an invariant effect of noxious stimulation but depends instead on the response measure, test time, and type of noxious stimulus. Furthermore, the results suggest that Dishabituation and sensitization may not involve different processes at the behavioral level; rather the observed differences between them may be due largely to an interaction between habituation and inhibition.
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a simplified preparation for relating cellular events to behavior contribution of le and unidentified siphon sensory neurons to mediation and habituation of the aplysia gill and siphon withdrawal reflex
The Journal of Neuroscience, 1997Co-Authors: Lina Frost, Eric R. Kandel, Tracey E. Cohen, Saul W Kaplan, Victor Henzi, Robert D. HawkinsAbstract:We have begun to analyze several elementary forms of learning in a simple preparation consisting of the isolated mantle organs and abdominal ganglion of Aplysia. Previous studies suggested that plasticity at siphon sensory neuron synapses contributes to habituation and Dishabituation of the gill- and siphon-withdrawal reflex in this preparation. We next wished to identify the sensory neurons that participate in the reflex and examine their plasticity more directly. To investigate the contribution of the LE siphon mechanosensory cells, we recorded from them and gill or siphon motor neurons during the same siphon stimulation that has been used in behavioral experiments in this preparation. Our results indicate that the LE cells make a substantial contribution to the evoked response in the motor neurons under these conditions, but they suggest that other as yet unidentified siphon sensory neurons with lower thresholds and shorter latencies also contribute. In addition, we find that homosynaptic depression of monosynaptic postsynaptic potentials (PSPs) from LE sensory cells makes an important contribution to habituation of the response in the motor neurons. To investigate plasticity of PSPs from the unidentified sensory neurons, we recorded the PSP that was produced in a motor neuron by water-movement stimulation of the siphon, which does not cause firing of LE cells. Our results suggest that PSPs from the unidentified sensory neurons and the LE neurons undergo similar plasticity during habituation and Dishabituation training. These results support the idea that plasticity at synapses of both LE and unidentified sensory neurons contributes to habituation and Dishabituation of the reflex response in this preparation.
Michael Kavšek - One of the best experts on this subject based on the ideXlab platform.
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The comparator model of infant visual habituation and Dishabituation: recent insights.
Developmental psychobiology, 2012Co-Authors: Michael KavšekAbstract:Current knowledge of the perceptual and cognitive abilities in infancy is largely based on the visual habituation-Dishabituation method. According to the comparator model [e.g., Sokolov (1963a) Perception and the conditioned reflex. Oxford: Pergamon Press], habituation refers to stimulus encoding and Dishabituation refers to discriminatory memory performance. The review also describes the dual-process theory and the attention disengagement approach. The dual-process theory points to the impact of natural stimulus preferences on habituation-Dishabituation processes. The attention disengagement approach emphasizes the contribution of the ability to shift the attention away from a stimulus. Moreover, arguments for the cognitive interpretation of visual habituation and Dishabituations are discussed. These arguments are provided by physiological studies and by research on interindividual differences. Overall, the review shows that current research supports the comparator model. It emphasizes that the investigation of habituation and Dishabituation expands our understanding of visual attention processes in infants.
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Visual habituation and Dishabituation in preterm infants: A review and meta-analysis
Research in developmental disabilities, 2010Co-Authors: Michael Kavšek, Marc H. BornsteinAbstract:We review comparative studies of infant habituation and Dishabituation performance focusing on preterm infants. Habituation refers to cognitive encoding, and Dishabituation refers to discrimination and memory. If habituation and Dishabituation constitute basic information-processing skills, and preterm infants suffer cognitive disadvantages, then preterms should show diminished habituation and Dishabituation performance. Our review provides evidence that preterm infants' habituation and Dishabituation are impoverished relative to term infants. On the whole, effect sizes indicated that the differences between preterms and terms are of a medium magnitude. We also find that preterms' performance is moderated by risk factors, stimulus materials, procedural variables, and age. These factors need to be taken into account in the construction of tests in which habituation-Dishabituation tasks are employed. Overall, the habituation-Dishabituation paradigm presents a promising approach in the diagnosis of cognitive status and development in preterm infants.
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Predicting Later IQ from Infant Visual Habituation and Dishabituation: A Meta-Analysis.
Journal of Applied Developmental Psychology, 2004Co-Authors: Michael KavšekAbstract:Abstract The present meta-analysis of the predictive validity of visual habituation and visual Dishabituation shows that the weighted and normalized average correlation between infant habituation/Dishabituation and childhood cognitive performance is .37. In contrast to the findings of earlier reviews, for risk samples, Dishabituation is apparently superior to habituation in predicting later intelligence, whereas for nonclinical samples, there is evidence to suggest that the opposite pattern holds true; that is, predictive validity is higher for habituation than for Dishabituation. Prediction from habituation/Dishabituation is not affected by when these variables are assessed in infancy. Furthermore, the predictive validity of habituation/Dishabituation is substantial and stable up until adolescence. These and further conclusions are elaborated upon and discussed.
Bruce D Mccandliss - One of the best experts on this subject based on the ideXlab platform.
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Dishabituation of the BOLD response to speech sounds
Behavioral and Brain Functions, 2005Co-Authors: Jason D Zevin, Bruce D MccandlissAbstract:Background Neural systems show habituation responses at multiple levels, including relatively abstract language categories. Dishabituation – responses to non-habituated stimuli – can provide a window into the structure of these categories, without requiring an overt task. Methods We used an event-related fMRI design with short interval habituation trials, in which trains of stimuli were presented passively during 1.5 second intervals of relative silence between clustered scans. Trains of four identical stimuli (standard trials) and trains of three identical stimuli followed by a stimulus from a different phonetic category (deviant trials) were presented. This paradigm allowed us to measure and compare the time course of overall responses to speech, and responses to phonetic change. Results Comparisons between responses to speech and silence revealed strong responses throughout the extent of superior temporal gyrus (STG) bilaterally. Comparisons between deviant and standard trials revealed Dishabituation responses in a restricted region of left posterior STG, near the border with supramarginal gyrus (SMG). Novelty responses to deviant trials were also observed in right frontal regions and hippocampus. Conclusion A passive, Dishabituation paradigm provides results similar to studies requiring overt responses. This paradigm can readily be extended for the study of pre-attentive processing of speech in populations such as children and second-language learners whose overt behavior is often difficult to interpret because of ancillary task demands.
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Dishabituation of the BOLD response to speech sounds
Behavioral and brain functions : BBF, 2005Co-Authors: Jason D Zevin, Bruce D MccandlissAbstract:Background Neural systems show habituation responses at multiple levels, including relatively abstract language categories. Dishabituation – responses to non-habituated stimuli – can provide a window into the structure of these categories, without requiring an overt task.
Cinzia Chiandetti - One of the best experts on this subject based on the ideXlab platform.
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Short-term memory in habituation and Dishabituation of newborn chicks' freezing response.
Journal of experimental psychology. Animal learning and cognition, 2018Co-Authors: Andrea Dissegna, Massimo Turatto, Cinzia ChiandettiAbstract:Cognitive models of habituation and Dishabituation postulate that the latter is attributable to the perturbation of the model of the repeated stimulation stored in short-term memory (STM) by the occurrence of a new stimulus, called dishabituator. However, although both behavioral phenomena depend on STM, previous studies in Aplysia have found that Dishabituation seems to require further steps of development of the STM system to emerge. Here, we addressed whether this is a universal condition for the appearance of the 2 forms of learning, namely whether Dishabituation must necessarily follow habituation. To this aim, we studied habituation and Dishabituation of the freezing response to a sudden acoustic stimulation in newly hatched chicks (1 day old vs. 3 days old). The results showed that in chicks, Dishabituation was fully present a few hours after hatching, a pattern of results indicating that, in this precocial avian species, habituation and Dishabituation share the same developmental trajectory and the underlying STM mechanisms are simultaneously operative soon after birth. (PsycINFO Database Record (c) 2018 APA, all rights reserved).