Magnesium efflux from Drosophila Kenyon Cells is critical for normal and diet-enhanced long-term memory
- University of Oxford, United Kingdom
- Osaka University, Japan
Abstract
Dietary magnesium (Mg2+) supplementation can enhance memory in young and aged rats. Memory-enhancing capacity was largely ascribed to increases in hippocampal synaptic density and elevated expression of the NR2B subunit of the NMDA-type glutamate receptor. Here we show that Mg2+ feeding also enhances long-term memory in Drosophila. Normal and Mg2+ enhanced fly memory appears independent of NMDA receptors in the mushroom body and instead requires expression of a conserved CNNM-type Mg2+-efflux transporter encoded by the unextended (uex) gene. UEX contains a putative cyclic nucleotide-binding homology domain and its mutation separates a vital role for uex from a function in memory. Moreover, UEX localization in mushroom body Kenyon Cells is altered in memory defective flies harboring mutations in cAMP-related genes. Functional imaging suggests that UEX-dependent efflux is required for slow rhythmic maintenance of Kenyon Cell Mg2+. We propose that regulated neuronal Mg2+ efflux is critical for normal and Mg2+ enhanced memory.
Data availability
Behaviour data from T-maza assays deposited in Dryad Digital Repository (doi:10.5061/dryad.q2bvq83hs). All other data generated or analysed during this study are included in the manuscript and supporting files.
-
Behavior data from T-maze assayDryad Digital Repository, doi:10.5061/dryad.q2bvq83hs.
-
Imaging data from ex-vivo MagIC assay Part IIDryad Digital Repository, doi:10.5061/dryad.zpc866t7d.
-
MagFRET signal from fixed brainDryad Digital Repository, doi:10.5061/dryad.dv41ns1wp.
-
Imaging data from ex-vivo MagIC assay Part IDryad Digital Repository, doi:10.5061/dryad.k0p2ngf6z.
-
Immuno-Fluorescence data from confocal scanningDryad Digital Repository, doi:10.5061/dryad.80gb5mkpx.
Article and author information
Author details
Funding
Wellcome (200846/Z/16/Z)
- Scott Waddell
European Commission (789274)
- Scott Waddell
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Wu et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 3,731
- views
-
- 468
- downloads
-
- 9
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Magnesium efflux from Drosophila Kenyon Cells is critical for normal and diet-enhanced long-term memory
eLife 9:e61339.
https://doi.org/10.7554/eLife.61339
Further reading
-
Magnesium supplements help boost long-term memory in flies
-
- Neuroscience
Detecting causal relations structures our perception of events in the world. Here, we determined for visual interactions whether generalized (i.e. feature-invariant) or specialized (i.e. feature-selective) visual routines underlie the perception of causality. To this end, we applied a visual adaptation protocol to assess the adaptability of specific features in classical launching events of simple geometric shapes. We asked observers to report whether they observed a launch or a pass in ambiguous test events (i.e. the overlap between two discs varied from trial to trial). After prolonged exposure to causal launch events (the adaptor) defined by a particular set of features (i.e. a particular motion direction, motion speed, or feature conjunction), observers were less likely to see causal launches in subsequent ambiguous test events than before adaptation. Crucially, adaptation was contingent on the causal impression in launches as demonstrated by a lack of adaptation in non-causal control events. We assessed whether this negative aftereffect transfers to test events with a new set of feature values that were not presented during adaptation. Processing in specialized (as opposed to generalized) visual routines predicts that the transfer of visual adaptation depends on the feature similarity of the adaptor and the test event. We show that the negative aftereffects do not transfer to unadapted launch directions but do transfer to launch events of different speeds. Finally, we used colored discs to assign distinct feature-based identities to the launching and the launched stimulus. We found that the adaptation transferred across colors if the test event had the same motion direction as the adaptor. In summary, visual adaptation allowed us to carve out a visual feature space underlying the perception of causality and revealed specialized visual routines that are tuned to a launch’s motion direction.
