On June 1, 2010, the Proceedings of the National Academy of Sciences USA published a research article from ION entitled "Functional feedback from mushroom bodies to antennal lobes in the Drosophila olfactory pathway". This work was carried out by postdoctoral fellow Dr. Aiqun Hu and graduate student Wei Zhang from the Laboratory of Dr. Zuoren Wang at ION.

Feedback plays important roles in sensory processing. Mushroom bodies are believed to be involved in olfactory learning/memory and multisensory integration in insects. Previous cobalt-labeling studies have suggested the existence of feedback from the mushroom bodies to the antennal lobes in the honey bee. In this study, Authors investigated functional feedback from Drosophila mushroom bodies to the antennal lobes through ectopic expression of the ATP receptor P2X2 in the Kenyon cells of mushroom bodies. Activation of Kenyon cells induced depolarization in projection neurons and local interneurons in the antennal lobes in a nicotinic receptor-dependent manner. Activation of Kenyon cell βγ-lobes in the mushroom body induced more potent responses in the antennal lobe neurons than activation of Kenyon cell somata. These results indicate that functional feedback from Kenyon cells to projection neurons and local interneurons is present in Drosophila and is likely mediated by the βγ-lobes. The presence of this functional feedback from the mushroom bodies to the antennal lobes suggests top-down modulation of olfactory information processing in Drosophila.

This study was supported by grants from the 973-2006CB806604, NSF30625020, NSF30621062, and Chinese Academy of Sciences Bai Ren Project and KSCX1-YW-R-31 (to Z.W.) and China Postdoctoral Foundation-20080430704 and Shanghai Postdoctoral Fund-07R214155 (to A.H.).