The Drosophila cell-adhesion molecule Klingon is required for long-term memory and is regulated by Notch signaling activity

Abstract

Although cell adhesion molecules have been implicated in long-lasting synaptic plasticity, their contribution to the long-lasting memory is not clear. In Drosophila, long-lasting memory can be dissected into a translation-dependent long-term memory (LTM) or a translation-independent anesthesia resistant memory (ARM). A behavioral screen for defects in long-lasting memory identified the ruslan (rus) mutant, which is disrupted in klingon (klg), a member of the Drosophila immunoglobulin superfamily of cell adhesion molecules. Strikingly, Klg is regulated by the Notch signaling pathway, and Notch induced enhancement of LTM is disrupted by the klg mutation. Klg is significantly localized at the juncture between neuropil and glia in the adult brain. Furthermore, LTM was restored in klg mutant when klg is expressed either in neuronal or glial cells, suggesting that Notch regulates Klg expression to establish neuron-glia communication required for LTM formation.