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.
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.
- Scott Waddell
- Scott Waddell
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- K VijayRaghavan, National Centre for Biological Sciences, Tata Institute of Fundamental Research, India
© 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.