scholarly journals Behavioral Tagging: A Translation of the Synaptic Tagging and Capture Hypothesis

2015 ◽  
Vol 2015 ◽  
pp. 1-21 ◽  
Author(s):  
Diego Moncada ◽  
Fabricio Ballarini ◽  
Haydée Viola
Keyword(s):  
Experimental Data ◽  
Memory Consolidation ◽  
Electrical Stimulus ◽  
Memory Formation ◽  
Synaptic Specificity ◽  
Molecular Machinery ◽  
Synaptic Changes ◽  
Plastic Changes ◽  
Synaptic Tagging And Capture ◽  
Related Proteins

Similar molecular machinery is activated in neurons following an electrical stimulus that induces synaptic changes and after learning sessions that trigger memory formation. Then, to achieve perdurability of these processes protein synthesis is required for the reinforcement of the changes induced in the network. The synaptic tagging and capture theory provided a strong framework to explain synaptic specificity and persistence of electrophysiological induced plastic changes. Ten years later, the behavioral tagging hypothesis (BT) made use of the same argument, applying it to learning and memory models. The hypothesis postulates that the formation of lasting memories relies on at least two processes: the setting of a learning tag and the synthesis of plasticity related proteins, which once captured at tagged sites allow memory consolidation. BT explains how weak events, only capable of inducing transient forms of memories, can result in lasting memories when occurring close in time with other behaviorally relevant experiences that provide proteins. In this review, we detail the findings supporting the existence of BT process in rodents, leading to the consolidation, persistence, and interference of a memory. We focus on the molecular machinery taking place in these processes and describe the experimental data supporting the BT in humans.

scholarly journals The Autophagy Machinery in Human-Parasitic Protists; Diverse Functions for Universally Conserved Proteins

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1258
Author(s):  
Hirokazu Sakamoto ◽  
Kumiko Nakada-Tsukui ◽  
Sébastien Besteiro
Keyword(s):  
Membrane Vesicle ◽  
Model Organisms ◽  
Unicellular Eukaryotes ◽  
Current State ◽  
Important Challenge ◽  
Molecular Machinery ◽  
Cellular Machinery ◽  
Apparent Reduction ◽  
Related Proteins ◽  
Genome Projects

Autophagy is a eukaryotic cellular machinery that is able to degrade large intracellular components, including organelles, and plays a pivotal role in cellular homeostasis. Target materials are enclosed by a double membrane vesicle called autophagosome, whose formation is coordinated by autophagy-related proteins (ATGs). Studies of yeast and Metazoa have identified approximately 40 ATGs. Genome projects for unicellular eukaryotes revealed that some ATGs are conserved in all eukaryotic supergroups but others have arisen or were lost during evolution in some specific lineages. In spite of an apparent reduction in the ATG molecular machinery found in parasitic protists, it has become clear that ATGs play an important role in stage differentiation or organelle maintenance, sometimes with an original function that is unrelated to canonical degradative autophagy. In this review, we aim to briefly summarize the current state of knowledge in parasitic protists, in the light of the latest important findings from more canonical model organisms. Determining the roles of ATGs and the diversity of their functions in various lineages is an important challenge for understanding the evolutionary background of autophagy.

scholarly journals Regional synapse gain and loss accompany memory formation in larval zebrafish

2022 ◽  
Vol 119 (3) ◽  
pp. e2107661119
Author(s):  
William P. Dempsey ◽  
Zhuowei Du ◽  
Anna Nadtochiy ◽  
Colton D. Smith ◽  
Karl Czajkowski ◽  
...  
Keyword(s):  
Classical Conditioning ◽  
Structural Changes ◽  
Memory Formation ◽  
Excitatory Synapses ◽  
Microscopy Imaging ◽  
Functional Changes ◽  
Larval Zebrafish ◽  
Before And After ◽  
Synaptic Changes ◽  
With Memory

Defining the structural and functional changes in the nervous system underlying learning and memory represents a major challenge for modern neuroscience. Although changes in neuronal activity following memory formation have been studied [B. F. Grewe et al., Nature 543, 670–675 (2017); M. T. Rogan, U. V. Stäubli, J. E. LeDoux, Nature 390, 604–607 (1997)], the underlying structural changes at the synapse level remain poorly understood. Here, we capture synaptic changes in the midlarval zebrafish brain that occur during associative memory formation by imaging excitatory synapses labeled with recombinant probes using selective plane illumination microscopy. Imaging the same subjects before and after classical conditioning at single-synapse resolution provides an unbiased mapping of synaptic changes accompanying memory formation. In control animals and animals that failed to learn the task, there were no significant changes in the spatial patterns of synapses in the pallium, which contains the equivalent of the mammalian amygdala and is essential for associative learning in teleost fish [M. Portavella, J. P. Vargas, B. Torres, C. Salas, Brain Res. Bull. 57, 397–399 (2002)]. In zebrafish that formed memories, we saw a dramatic increase in the number of synapses in the ventrolateral pallium, which contains neurons active during memory formation and retrieval. Concurrently, synapse loss predominated in the dorsomedial pallium. Surprisingly, we did not observe significant changes in the intensity of synaptic labeling, a proxy for synaptic strength, with memory formation in any region of the pallium. Our results suggest that memory formation due to classical conditioning is associated with reciprocal changes in synapse numbers in the pallium.

scholarly journals Parvalbumin-expressing interneurons coordinate hippocampal network dynamics required for memory consolidation

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Nicolette Ognjanovski ◽  
Samantha Schaeffer ◽  
Jiaxing Wu ◽  
Sima Mofakham ◽  
Daniel Maruyama ◽  
...  
Keyword(s):  
Memory Consolidation ◽  
Activity Patterns ◽  
Memory Formation ◽  
Contextual Fear Conditioning ◽  
Long Term Memory ◽  
Ca1 Neurons ◽  
Functional Connections ◽  
The Hours ◽  
Hippocampal Area ◽  
Episodic Memories

Abstract Activity in hippocampal area CA1 is essential for consolidating episodic memories, but it is unclear how CA1 activity patterns drive memory formation. We find that in the hours following single-trial contextual fear conditioning (CFC), fast-spiking interneurons (which typically express parvalbumin (PV)) show greater firing coherence with CA1 network oscillations. Post-CFC inhibition of PV+ interneurons blocks fear memory consolidation. This effect is associated with loss of two network changes associated with normal consolidation: (1) augmented sleep-associated delta (0.5–4 Hz), theta (4–12 Hz) and ripple (150–250 Hz) oscillations; and (2) stabilization of CA1 neurons’ functional connectivity patterns. Rhythmic activation of PV+ interneurons increases CA1 network coherence and leads to a sustained increase in the strength and stability of functional connections between neurons. Our results suggest that immediately following learning, PV+ interneurons drive CA1 oscillations and reactivation of CA1 ensembles, which directly promotes network plasticity and long-term memory formation.

scholarly journals An Emerging Role of m6A in Memory: A Case for Translational Priming

2020 ◽  
Vol 21 (20) ◽  
pp. 7447
Author(s):  
Amanda M. Leonetti ◽  
Ming Yin Chu ◽  
Fiona O. Ramnaraign ◽  
Samuel Holm ◽  
Brandon J. Walters
Keyword(s):  
Learning And Memory ◽  
Memory Consolidation ◽  
Protein Translation ◽  
Memory Formation ◽  
Current Data ◽  
Neuron Development ◽  
Neuronal Functions ◽  
The Brain ◽  
Fine Tune

Investigation into the role of methylation of the adenosine base (m6A) of RNA has only recently begun, but it quickly became apparent that m6A is able to control and fine-tune many aspects of mRNA, from splicing to translation. The ability of m6A to regulate translation distally, away from traditional sites near the nucleus, quickly caught the eye of neuroscientists because of implications for selective protein translation at synapses. Work in the brain has demonstrated how m6A is functionally required for many neuronal functions, but two in particular are covered at length here: The role of m6A in 1) neuron development; and 2) memory formation. The purpose of this review is not to cover all data about m6A in the brain. Instead, this review will focus on connecting mechanisms of m6A function in neuron development, with m6A’s known function in memory formation. We will introduce the concept of “translational priming” and discuss how current data fit into this model, then speculate how m6A-mediated translational priming during memory consolidation can regulate learning and memory locally at the synapse.

NMDA receptors: Substrates or modulators of memory formation

1997 ◽  
Vol 20 (4) ◽  
pp. 634-634 ◽  
Author(s):  
David L. Walker ◽  
Paul E. Gold
Keyword(s):  
Nmda Receptors ◽  
Memory Consolidation ◽  
Memory Formation ◽  
Current Evidence ◽  
General Hypothesis ◽  
Attentional Processes

We agree with Shors & Matzel's general hypothesis that the proposed link between NMDA-dependent LTP and memory is weak. They suggest that NMDA-dependent LTP is important to arousal or attentional processes which influence learning in an anterograde manner. However, current evidence is also consistent with the view that NMDA receptors modulate memory consolidation retroactively, as occurs in several other receptor classes.

scholarly journals Locus Coeruleus and Dopamine-Dependent Memory Consolidation

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Miwako Yamasaki ◽  
Tomonori Takeuchi
Keyword(s):  
Synaptic Plasticity ◽  
Locus Coeruleus ◽  
Memory Consolidation ◽  
Molecular Mechanisms ◽  
Memory Enhancement ◽  
Long Time ◽  
Related Proteins ◽  
Anatomical Evidence ◽  
Environmental Novelty

Most everyday memories including many episodic-like memories that we may form automatically in the hippocampus (HPC) are forgotten, while some of them are retained for a long time by a memory stabilization process, called initial memory consolidation. Specifically, the retention of everyday memory is enhanced, in humans and animals, when something novel happens shortly before or after the time of encoding. Converging evidence has indicated that dopamine (DA) signaling via D1/D5receptors in HPC is required for persistence of synaptic plasticity and memory, thereby playing an important role in the novelty-associated memory enhancement. In this review paper, we aim to provide an overview of the key findings related to D1/D5receptor-dependent persistence of synaptic plasticity and memory in HPC, especially focusing on the emerging evidence for a role of the locus coeruleus (LC) in DA-dependent memory consolidation. We then refer to candidate brain areas and circuits that might be responsible for detection and transmission of the environmental novelty signal and molecular and anatomical evidence for the LC-DA system. We also discuss molecular mechanisms that might mediate the environmental novelty-associated memory enhancement, including plasticity-related proteins that are involved in initial memory consolidation processes in HPC.

Differential histone acetylation in the Amygdala leads to fear memory consolidation and extinction

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Vandana Ranjan ◽  
Sanjay Singh ◽  
Sarfraj Ahmad Siddiqui ◽  
M Y Khan ◽  
Anand Prakash
Keyword(s):  
Histone Acetylation ◽  
Memory Consolidation ◽  
Histone H3 ◽  
Fear Memory ◽  
Memory Formation ◽  
Acetylation Level ◽  
Creb Activation ◽  
Conditioning Model ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

<p>In the present study, a fear-conditioning model in rats was used to gauge the changes in the histone acetylation level in the<br />different nuclei of amygdala during fear memory consolidation and its extinction. It was found by immunohistochemical<br />examination of Amygdala that during the fear memory consolidation histone H3 acetylation level was significantly<br />increased in the Central amygdala (CeA), the output of the fear circuitry, as compared to the unconditioned group and<br />subsequently, when this fear memory was extinguished during fear extinction, the histone H3 acetylation levels decreased<br />significantly as compared to the conditioned group. However, in another nuclei of the amygdala, the intercalated cells<br />(ITCs) the Acetyl H3 levels increased during extinction and but not in the conditioned group as compared to the<br />unconditioned group. The p-ERK and p-CREB levels also significantly varied in the different nuclei of amygdala<br />between the two groups and showed correlation with the Histone acetylation changes observed in these groups. In<br />conclusion the present study points out that the memory formation, during fear memory consolidation and its extinction,<br />may be dependent on differential neuronal activity under epigenetic control through acetylation at k-9 residue of histone<br />H3, in different regions of the amygdala as evident by the p-ERK and p-CREB activation, which are the markers for<br />activity of neurons and memory formation.</p>

scholarly journals Hunting for Synaptic Tagging and Capture in Memory Formation

2007 ◽  
Vol 27 (47) ◽  
pp. 12761-12763 ◽  
Author(s):  
J. Viosca ◽  
D. Jancic ◽  
J. P. Lopez-Atalaya ◽  
E. Benito
Keyword(s):  
Memory Formation ◽  
Synaptic Tagging And Capture
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