scholarly journals Spaced training forms complementary long-term memories of opposite valence inDrosophila

2019 ◽  
Author(s):  
Pedro F. Jacob ◽  
Scott Waddell
Keyword(s):  
Dopaminergic Neurons ◽  
Mushroom Body ◽  
Long Term Memory ◽  
Odor Preference ◽  
Additional Information ◽  
Relative Safety ◽  
Multiple Trials ◽  
Over Time ◽  
Odor Conditioning

AbstractForming long-term memory (LTM) in many cases requires repetitive experience spread over time. InDrosophila, aversive olfactory LTM is optimal following spaced training, multiple trials of differential odor conditioning with rest intervals. Studies often compare memory after spaced to that after massed training, same number of trials without interval. Here we show flies acquire additional information after spaced training, forming an aversive memory for the shock-paired odor and a ‘safety-memory’ for the explicitly unpaired odor. Safety-memory requires repetition, order and spacing of the training trials and relies on specific subsets of rewarding dopaminergic neurons. Co-existence of the aversive and safety memories can be measured as depression of odor-specific responses at different combinations of junctions in the mushroom body output network. Combining two particular outputs appears to signal relative safety. Learning a complementary safety memory thereby augments LTM performance after spaced training by making the odor preference more certain.

scholarly journals Differential Conditioning Produces Merged Long-term Memory in Drosophila

2021 ◽  
Author(s):  
Bohan Zhao ◽  
Jiameng Sun ◽  
Qian Li ◽  
Yi Zhong
Keyword(s):  
Conditioned Stimulus ◽  
Dopaminergic Neurons ◽  
Mushroom Body ◽  
Differential Conditioning ◽  
Long Term Memory ◽  
Single Trial ◽  
Kenyon Cells ◽  
Output Neurons ◽  
New Protein

AbstractMultiple spaced trials of aversive differential conditioning can produce two independent longterm memories (LTMs) of opposite valence. One is an aversive memory for avoiding the conditioned stimulus (CS+), and the other is a safety memory for approaching the non-conditioned stimulus (CS−). Here, we show that a single trial of aversive differential conditioning yields one merged LTM (mLTM) for avoiding both CS+ and CS−. Such mLTM can be detected after sequential exposures to the shock-paired CS+ and unpaired CS−, and be retrieved by either CS+ or CS−. The formation of mLTM relies on triggering aversive-reinforcing dopaminergic neurons and subsequent new protein synthesis. Expressing mLTM involves αβ Kenyon cells and corresponding approach-directing mushroom body output neurons (MBONs), in which similar-amplitude long-term depression of responses to CS+ and CS− seems to signal the mLTM. Our results suggest that animals can develop distinct strategies for occasional and repeated threatening experiences.

scholarly journals Differential conditioning produces merged long-term memory in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Bohan Zhao ◽  
JIameng Sun ◽  
Qian Li ◽  
Yi Zhong
Keyword(s):  
Conditioned Stimulus ◽  
Dopaminergic Neurons ◽  
Mushroom Body ◽  
Differential Conditioning ◽  
Long Term Memory ◽  
Single Trial ◽  
Kenyon Cells ◽  
Output Neurons ◽  
New Protein

Multiple spaced trials of aversive differential conditioning can produce two independent long-term memories (LTMs) of opposite valence. One is an aversive memory for avoiding the conditioned stimulus (CS+), and the other is a safety memory for approaching the non-conditioned stimulus (CS-). Here, we show that a single trial of aversive differential conditioning yields one merged LTM (mLTM) for avoiding both CS+ and CS-. Such mLTM can be detected after sequential exposures to the shock-paired CS+ and unpaired CS-, and be retrieved by either CS+ or CS-. The formation of mLTM relies on triggering aversive-reinforcing dopaminergic neurons and subsequent new protein synthesis. Expressing mLTM involves αβ Kenyon cells and corresponding approach-directing mushroom body output neurons (MBONs), in which similar-amplitude long-term depression of responses to CS+ and CS- seems to signal the mLTM. Our results suggest that animals can develop distinct strategies for occasional and repeated threatening experiences.

scholarly journals Dissecting neural pathways for forgetting in Drosophila olfactory aversive memory

2015 ◽  
Vol 112 (48) ◽  
pp. E6663-E6672 ◽  
Author(s):  
Yichun Shuai ◽  
Areekul Hirokawa ◽  
Yulian Ai ◽  
Min Zhang ◽  
Wanhe Li ◽  
...  
Keyword(s):  
Reversal Learning ◽  
Dopaminergic Neurons ◽  
Mushroom Body ◽  
Biologically Active ◽  
Molecular Pathways ◽  
Neural Pathways ◽  
Active Process ◽  
Glutamatergic Neurons ◽  
Memory Decay ◽  
Over Time

Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-β′1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.

scholarly journals Upregulated energy metabolism in the Drosophila mushroom body is the trigger for long-term memory

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Pierre-Yves Plaçais ◽  
Éloïse de Tredern ◽  
Lisa Scheunemann ◽  
Séverine Trannoy ◽  
Valérie Goguel ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Mushroom Body ◽  
Long Term Memory ◽  
Term Memory

scholarly journals Long-term memory requires sequential protein synthesis in three subsets of mushroom body output neurons in Drosophila

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jie-Kai Wu ◽  
Chu-Yi Tai ◽  
Kuan-Lin Feng ◽  
Shiu-Ling Chen ◽  
Chun-Chao Chen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Mushroom Body ◽  
Long Term Memory ◽  
Term Memory ◽  
Output Neurons

scholarly journals Individual Differences in Learning Efficiency

2019 ◽  
Vol 28 (6) ◽  
pp. 607-613
Author(s):  
Kathleen B. McDermott ◽  
Christopher L. Zerr
Keyword(s):  
Individual Differences ◽  
Experimental Approach ◽  
Long Term Memory ◽  
Positive Relation ◽  
Future Directions ◽  
Term Memory ◽  
Learning Efficiency ◽  
Rate Of Learning ◽  
Over Time

Most research on long-term memory uses an experimental approach whereby participants are assigned to different conditions, and condition means are the measures of interest. This approach has demonstrated repeatedly that conditions that slow the rate of learning tend to improve later retention. A neglected question is whether aggregate findings at the level of the group (i.e., slower learning tends to improve retention) translate to the level of individual people. We identify a discrepancy whereby—across people—slower learning tends to coincide with poorer memory. The positive relation between learning rate (speed of learning) and retention (amount remembered after a delay) across people is referred to as learning efficiency. A more efficient learner can acquire information faster and remember more of it over time. We discuss potential characteristics of efficient learners and consider future directions for research.

scholarly journals Neuronal reactivation during post-learning sleep consolidates long-term memory in Drosophila

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Ugur Dag ◽  
Zhengchang Lei ◽  
Jasmine Q Le ◽  
Allan Wong ◽  
Daniel Bushey ◽  
...  
Keyword(s):  
Memory Consolidation ◽  
Dopaminergic Neurons ◽  
Learning Experience ◽  
Long Term Memory ◽  
Term Memory ◽  
Long Term Storage ◽  
Memory Acquisition ◽  
Underlying Mechanisms ◽  
Term Storage

Animals consolidate some, but not all, learning experiences into long-term memory. Across the animal kingdom, sleep has been found to have a beneficial effect on the consolidation of recently formed memories into long-term storage. However, the underlying mechanisms of sleep dependent memory consolidation are poorly understood. Here, we show that consolidation of courtship long-term memory in Drosophila is mediated by reactivation during sleep of dopaminergic neurons that were earlier involved in memory acquisition. We identify specific fan-shaped body neurons that induce sleep after the learning experience and activate dopaminergic neurons for memory consolidation. Thus, we provide a direct link between sleep, neuronal reactivation of dopaminergic neurons, and memory consolidation.

scholarly journals Features of subsyndromal and persistent delirium

2012 ◽  
Vol 200 (1) ◽  
pp. 37-44 ◽  
Author(s):  
David Meagher ◽  
Dimitrios Adamis ◽  
Paula Trzepacz ◽  
Maeve Leonard
Keyword(s):  
Rating Scale ◽  
Cognitive Test ◽  
Long Term Memory ◽  
Thought Process ◽  
Diagnostic Features ◽  
Term Memory ◽  
Subsyndromal Delirium ◽  
Short And Long Term ◽  
Over Time

BackgroundLongitudinal studies of delirium phenomenology are lacking.AimsWe studied features that characterise subsyndromal delirium and persistent delirium over time.MethodTwice-weekly evaluations of 100 adults with DSM-IV delirium using the Delirium Rating Scale – Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). The generalised estimating equation method identified symptom patterns distinguishing full syndromal from subsyndromal delirium and resolving from persistent delirium.ResultsParticipants (mean age 70.2 years (s.d. = 10.5)) underwent 323 assessments (range 2–9). Full syndromal delirium was significantly more severe than subsyndromal delirium for DRS-R98 thought process abnormalities, delusions, hallucinations, agitation, retardation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance, orientation and memory. Persistent full syndromal delirium had greater disturbance of DRS-R98 thought process abnormalities, delusions, agitation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance and orientation.ConclusionsFull syndromal delirium differs from subsyndromal delirium over time by greater severity of many cognitive and non-cognitive symptoms. Persistent delirium involves increasing prominence of recognised core diagnostic features and cognitive impairment.

scholarly journals Drosophila ORB protein in two mushroom body output neurons is necessary for long-term memory formation

2013 ◽  
Vol 110 (19) ◽  
pp. 7898-7903 ◽  
Author(s):  
T.-P. Pai ◽  
C.-C. Chen ◽  
H.-H. Lin ◽  
A.-L. Chin ◽  
J. S.-Y. Lai ◽  
...  
Keyword(s):  
Mushroom Body ◽  
Memory Formation ◽  
Long Term Memory ◽  
Term Memory ◽  
Output Neurons
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