Learning and Memory
SCIE-ISI SCOPUS (1994-2023)
1072-0502
1549-5485
Mỹ
Cơ quản chủ quản: Cold Spring Harbor Laboratory Press , COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT
Lĩnh vực:
Neuropsychology and Physiological PsychologyCellular and Molecular NeuroscienceCognitive Neuroscience
Các bài báo tiêu biểu
Context and Behavioral Processes in Extinction: Table 1.This article provides a selective review and integration of the behavioral
literature on Pavlovian extinction. The first part reviews evidence that
extinction does not destroy the original learning, but instead generates new
learning that is especially context-dependent. The second part examines
insights provided by research on several related behavioral phenomena (the
interference paradigms, conditioned inhibition, and inhibition despite
reinforcement). The final part examines four potential causes of extinction:
the discrimination of a new reinforcement rate, generalization decrement,
response inhibition, and violation of a reinforcer expectation. The data are
consistent with behavioral models that emphasize the role of generalization
decrement and expectation violation, but would be more so if those models were
expanded to better accommodate the finding that extinction involves a
context-modulated form of inhibitory learning.
Tập 11 Số 5 - Trang 485-494 - 2004
From Acquisition to Consolidation: On the Role of Brain-Derived Neurotrophic Factor Signaling in Hippocampal-Dependent LearningOne of the most rigorously investigated problems in modern neuroscience is to decipher the mechanisms by which experience-induced changes in the central nervous system are translated into behavioral acquisition, consolidation, retention, and subsequent recall of information. Brain-derived neurotrophic factor (BDNF) has recently emerged as one of the most potent molecular mediators of not only central synaptic plasticity, but also behavioral interactions between an organism and its environment. Recent experimental evidence indicates that BDNF modulates synaptic transmission and plasticity by acting across different spatial and temporal domains. BDNF signaling evokes both short- and long-term periods of enhanced synaptic physiology in both pre- and postsynaptic compartments of central synapses. Specifically, BDNF/TrkB signaling converges on the MAP kinase pathway to enhance excitatory synaptic transmission in vivo, as well as hippocampal-dependent learning in behaving animals. Emerging concepts of the intracellular signaling cascades involved in synaptic plasticity induced through environmental interactions resulting in behavioral learning further support the contention that BDNF/TrkB signaling plays a fundamental role in mediating enduring changes in central synaptic structure and function. Here we review recent literature showing the involvement of BDNF/TrkB signaling in hippocampal-dependent learning paradigms, as well as in the types of cellular plasticity proposed to underlie learning and memory.
Tập 9 Số 5 - Trang 224-237 - 2002
Enhanced Human Memory Consolidation With Post-Learning Stress: Interaction With the Degree of Arousal at EncodingAbundant evidence indicates that endogenous stress hormones such as
epinephrine and corticosterone modulate memory consolidation in animals. We
recently provided the first demonstration that an endogenous stress hormone
(epinephrine) can enhance human memory consolidation. However, these findings
also suggested that post-learning stress hormone activation does not uniformly
enhance memory for all recently acquired information; rather, that it
interacts with the degree of arousal at initial encoding of material in
modulating memory for the material. Here we tested this hypothesis by
administering cold pressor stress (CPS) or a control procedure to subjects
after they viewed slides of varying emotional content, and assessing memory
for the slides 1 wk later. CPS, which significantly elevated salivary cortisol
levels, enhanced memory for emotionally arousing slides compared with the
controls, but did not affect memory for relatively neutral slides. These
findings further support the view that post-learning stress hormone-related
activity interacts with arousal at initial encoding to modulate memory
consolidation.
Tập 10 Số 4 - Trang 270-274 - 2003
Sex influences on the neurobiology of learning and memoryIn essentially every domain of neuroscience, the generally implicit assumption that few, if any, meaningful differences exist between male and female brain function is being challenged. Here we address how this development is influencing studies of the neurobiology of learning and memory. While it has been commonly held that males show an advantage on spatial tasks, and females on verbal tasks, there is increasing evidence that sex differences are more widespread than previously supposed. Differing performance between the sexes have been observed on a number of common learning tasks in both the human and animal literature, many neither purely spatial nor verbal. We review sex differences reported in various areas to date, while attempting to identify common features of sexually dimorphic tasks, and to place these differences in a neurobiological context. This discussion focuses on studies of four classes of memory tasks for which sex differences have been frequently reported: spatial, verbal, autobiographical, and emotional memory. We conclude that the female verbal advantage extends into numerous tasks, including tests of spatial and autobiographical abilities, but that a small but significant advantage may exist for general episodic memory. We further suggest that for some tasks, stress evokes sex differences, which are not normally observed, and that these differences are mediated largely by interactions between stress and sex hormones.
Tập 16 Số 4 - Trang 248-266 - 2009
Different Training Procedures Recruit Either One or Two Critical Periods for Contextual Memory Consolidation, Each of Which Requires Protein Synthesis and PKAWe have used a combined genetic and pharmacological approach to define the time course of the requirement for protein kinase A (PKA) and protein synthesis in long-term memory for contextual fear conditioning in mice. The time course of amnesia in transgenic mice that express R(AB) and have genetically reduced PKA activity in the hippocampus parallels that observed both in mice treated with inhibitors of PKA and mice treated with inhibitors of protein synthesis. This PKA- and protein synthesis-dependent memory develops between 1 hr and 3 hr after training. By injecting the protein synthesis inhibitor anisomycin or the PKA inhibitor Rp-cAMPs at various times after training, we find that depending on the nature of training, contextual memory has either one or two brief consolidation periods requiring synthesis of new proteins, and each of these also requires PKA. Weak training shows two time periods of sensitivity to inhibitors of protein synthesis and PKA, whereas stronger training exhibits only one. These studies underscore the parallel dependence of long-term contextual memory on protein synthesis and PKA and suggest that different training protocols may recruit a common signaling pathway in distinct ways.
Tập 5 Số 4 - Trang 365-374 - 1998
Spontaneous RecoverySpontaneous recovery from extinction is one of the most basic phenomena of
Pavlovian conditioning. Although it can be studied by using a variety of
designs, some procedures are better than others for identifying the
involvement of underlying learning processes. A wide range of different
learning mechanisms has been suggested as being engaged by extinction, most of
which have implications for the nature of spontaneous recovery. However,
despite the centrality of the notion of spontaneous recovery to the
understanding of extinction, the empirical literature on its determinants is
relatively sparse and quite mixed. Its very ubiquity suggests that spontaneous
recovery has multiple sources.
Tập 11 Số 5 - Trang 501-509 - 2004
Running is the neurogenic and neurotrophic stimulus in environmental enrichmentEnvironmental enrichment (EE) increases dentate gyrus (DG) neurogenesis and brain-derived neurotrophic factor (BDNF) levels. However, running is considered an element of EE. To dissociate effects of physical activity and enrichment on hippocampal neurogenesis and BDNF levels, young female C57Bl/6 mice were housed under control, running, enrichment, or enrichment plus running conditions, and injected with bromodeoxyuridine. Cell genesis was assessed after 12 d and differentiation was analyzed 1 mo later. In addition, locomotor activity in the open field and hippocampal mature BDNF peptide levels were measured. Open-field adaptation was improved in all groups, compared to controls, but more so with running. New cell proliferation, survival, neuron number, and neurotrophin levels were enhanced only when running was accessible. We conclude that exercise is the critical factor mediating increased BDNF levels and adult hippocampal neurogenesis.
Tập 18 Số 9 - Trang 605-609 - 2011
Working memory, long-term memory, and medial temporal lobe functionEarly studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL.
Tập 19 Số 1 - Trang 15-25 - 2012
Environmental Enrichment Modifies the PKA-Dependence of Hippocampal LTP and Improves Hippocampus-Dependent MemorycAMP-dependent protein kinase (PKA) is critical for the expression of some forms of long-term potentiation (LTP) in area CA1 of the mouse hippocampus and for hippocampus-dependent memory. Exposure to spatially enriched environments can modify LTP and improve behavioral memory in rodents, but the molecular bases for the enhanced memory performance seen in enriched animals are undefined. We tested the hypothesis that exposure to a spatially enriched environment may alter the PKA dependence of hippocampal LTP. Hippocampal slices from enriched mice showed enhanced LTP following a single burst of 100-Hz stimulation in the Schaffer collateral pathway of area CA1. In slices from nonenriched mice, this single-burst form of LTP was less robust and was unaffected by Rp-cAMPS, an inhibitor of PKA. In contrast, the enhanced LTP in enriched mice was attenuated by Rp-cAMPS. Enriched slices expressed greater forskolin-induced, cAMP-dependent synaptic facilitation than did slices from nonenriched mice. Enriched mice showed improved memory for contextual fear conditioning, whereas memory for cued fear conditioning was unaffected following enrichment. Our data indicate that exposure of mice to spatial enrichment alters the PKA dependence of LTP and enhances one type of hippocampus-dependent memory. Environmental enrichment can transform the pharmacological profile of hippocampal LTP, possibly by altering the threshold for activity-dependent recruitment of the cAMP-PKA signaling pathway following electrical and chemical stimulation. We suggest that experience-dependent plasticity of the PKA dependence of hippocampal LTP may be important for regulating the efficacy of hippocampus-based memory.
Tập 8 Số 1 - Trang 26-34 - 2001
Different mechanisms of fear extinction dependent on length of time since fear acquisitionFear extinction is defined as a decline in conditioned fear responses (CRs) following nonreinforced exposure to a feared conditioned stimulus (CS). Behavioral evidence indicates that extinction is a form of inhibitory learning: Extinguished fear responses reappear with the passage of time (spontaneous recovery), a shift of context (renewal), and unsignaled presentations of the unconditioned stimulus (reinstatement). However, there also is evidence to suggest that extinction is an “unlearning” process corresponding to depotentiation of potentiated synapses within the amygdala. Because depotentiation is induced more readily at short intervals following LTP induction and is not inducible at all at a sufficient delay, it may be that extinction initiated shortly following fear acquisition preferentially engages depotentiation/“unlearning,” whereas extinction initiated at longer delays recruits a different mechanism. We investigated this possibility through a series of behavioral experiments examining the recoverability of conditioned fear following extinction. Consistent with an inhibitory learning mechanism of extinction, rats extinguished 24–72 h following acquisition exhibited moderate to strong reinstatement, renewal, and spontaneous recovery. In contrast, and consistent with an erasure mechanism, rats extinguished 10 min to 1 h after acquisition exhibited little or no reinstatement, renewal, or spontaneous recovery. These data support a model in which different neural mechanisms are recruited depending on the temporal delay of fear extinction.
Tập 13 Số 2 - Trang 216-223 - 2006