Behavior data from T-maze assay

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.