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
-
- 3,629
- views
-
- 461
- downloads
-
- 8
- 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
Life histories of oviparous species dictate high metabolic investment in the process of gonadal development leading to ovulation. In vertebrates, these two distinct processes are controlled by the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH), respectively. While it was suggested that a common secretagogue, gonadotropin-releasing hormone (GnRH), oversees both functions, the generation of loss-of-function fish challenged this view. Here, we reveal that the satiety hormone cholecystokinin (CCK) is the primary regulator of this axis in zebrafish. We found that FSH cells express a CCK receptor, and our findings demonstrate that mutating this receptor results in a severe hindrance to ovarian development. Additionally, it causes a complete shutdown of both gonadotropins secretion. Using in-vivo and ex-vivo calcium imaging of gonadotrophs, we show that GnRH predominantly activates LH cells, whereas FSH cells respond to CCK stimulation, designating CCK as the bona fide FSH secretagogue. These findings indicate that the control of gametogenesis in fish was placed under different neural circuits, that are gated by CCK.
