Magnesium efflux from Drosophila Kenyon cells is critical for normal and diet-enhanced long-term memory
Dietary magnesium (Mg<sup>2+</sup>) 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 Mg...
Main Authors: | , , , , , |
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Format: | Journal article |
Language: | English |
Published: |
eLife Sciences Publications
2020
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Summary: | Dietary magnesium (Mg<sup>2+</sup>) 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 Mg<sup>2+</sup> feeding also enhances long-term memory in Drosophila. Normal and Mg<sup>2+</sup>-enhanced fly memory appears independent of NMDA receptors in the mushroom body and instead requires expression of a conserved CNNM-type Mg<sup>2+</sup>-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 (KCs) 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 KC Mg<sup>2+</sup>. We propose that regulated neuronal Mg<sup>2+</sup> efflux is critical for normal and Mg<sup>2+</sup>-enhanced memory. |
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