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Jacob, P. F.

Publications and source records attributed to Jacob, P. F..

4 recordsLinked to original sources

Multisensory learning binds modality-specific neurons into a cross-modal memory engram

Withdrawal StatementThe authors have withdrawn this manuscript. After conducting replication experiments and reanalysing the original data, the authors discovered that the voltage imaging results are not reproducible. Additional voltage imaging work by the authors and their collaborators has not produced robust signals. Furthermore, errors in the pipeline originally used for data analysis could have led to the contamination of data. A complete reanalysis by the authors of the voltage imaging data independently from the original pipeline did not replicate the original analysis. Although the authors have replicated the behavioural and connectomic data and consider that the general conclusions of the article are substantiated, the authors have no confidence in the voltage imaging data. The authors would like to apologize for any inconvenience caused to their scientific colleagues and the readers of the journal. The authors would like to thank Waddell lab members, A. Cook, A. Miriyala and M. Klappenbach, who were involved in the replication experiments but are not authors of the original paper and M. Hoffmann, S. Thornquist and G. Maimon of Rockefeller University for identifying possible errors in the voltage data processing. All authors agree with the withdrawal, with the exception of P. F. Jacob who did not respond to correspondence. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

neuroscience↗

Different dopaminergic neurons signal absolute and relative aversive value in the Drosophila mushroom body.

Animals use prior experience to assign absolute (good or bad) and also relative (better or worse) value to new experience. These learned values guide appropriate later decision-making. While our understanding of how the dopaminergic system computes absolute value is relatively advanced, the mechanistic underpinnings of relative valuation are unclear. Here we reveal mechanisms of absolute and relative aversive valuation in Drosophila. Three types of punishment-sensitive dopaminergic neurons (DANs) drive intensity-scaled plasticity at their respective mushroom body output neuron (MBON) connections to code absolute aversive value. In contrast, by comparing current and previous aversive experiences the MBON-DAN network can code relative aversive value by recruiting a specific subtype of reward-coding dopaminergic neurons which assigns a better than value to the lesser of two aversive experiences. This study therefore provides an important functional consequence of having opposing populations of DANs and illustrates how these can operate together as a system within the MB network to code and compare sequential aversive experience to learn relative aversive value.

neuroscience↗

An opposing self-reinforced odor pre-exposure memory produces latent inhibition in Drosophila

Prior experience of a stimulus can inhibit subsequent acquisition or expression of a learned association of that stimulus. However, the neuronal manifestations of this learning effect, named latent inhibition (LI), are poorly understood. Here we show that odor pre-exposure produces LI of appetitive olfactory memory performance in Drosophila. Behavioral expression of LI requires that the context during memory testing resembles that during the odor pre-exposures. Odor pre-exposure forms an aversive memory that requires dopaminergic neurons that innervate the {gamma}2'1 and 3 mushroom body compartments - those to 3 exhibit increasing odor-driven activity with successive pre-exposures. In contrast, odor-specific responses of the corresponding mushroom body output neurons are suppressed. Odor pre-exposure therefore recruits specific dopaminergic neurons that provide teaching signals that attach negative valence to the odor itself. LI of Drosophila appetitive memory consequently results from a temporary and context-dependent retrieval deficit imposed by competition with this short-lived aversive memory.

neuroscience↗

Spaced training forms complementary long-term memories of opposite valence in Drosophila

Forming long-term memory (LTM) in many cases requires repetitive experience spread over time. In Drosophila, 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.

neuroscience↗