Diacylglycerol kinase promotes forgetting of aversive olfactory memory in Drosophila.

Abstract

Decades of neuroscience research utilizing Drosophila has led to enormous strides in uncovering genes that positively support the ability to form new memories or consolidate them for the long-term. However, recent research has revealed the existence of more rare but equally important memory suppressor genes whose normal function is to limit memory formation or even promote active forgetting. Here we report that RNAi targeting of diacylglycerol kinase (dgk), a regulator of lipid signaling, within the mushroom body memory circuitry, specifically enhances aversive olfactory memory retention while leaving learning and sensory-motor behavioural controls unaffected. Furthermore, memory retention is enhanced when targeting dgk in these circuits with two additional RNAi lines. Finally, using in vivo functional imaging, we offer evidence that dgk plays a role in regulating baseline synaptic transmission of memory circuits. While the exact mechanism for Dgk's synaptic effects and the implications for memory storage remain unclear, our findings implicate lipid signaling via Dgk as an important regulator of active-forgetting pathways. This work builds on our prior understanding of the importance of lipids in cognition by extended their role to memory suppression and active forgetting.