Image_1_Calcium in Kenyon Cell Somata as a Substrate for an Olfactory Sensory Memory in Drosophila.TIF Alja Lüdke Georg Raiser Johannes Nehrkorn Andreas V. M. Herz C. Giovanni Galizia Paul Szyszka 10.3389/fncel.2018.00128.s001 https://frontiersin.figshare.com/articles/figure/Image_1_Calcium_in_Kenyon_Cell_Somata_as_a_Substrate_for_an_Olfactory_Sensory_Memory_in_Drosophila_TIF/6796217 <p>Animals can form associations between temporally separated stimuli. To do so, the nervous system has to retain a neural representation of the first stimulus until the second stimulus appears. The neural substrate of such sensory stimulus memories is unknown. Here, we search for a sensory odor memory in the insect olfactory system and characterize odorant-evoked Ca<sup>2+</sup> activity at three consecutive layers of the olfactory system in Drosophila: in olfactory receptor neurons (ORNs) and projection neurons (PNs) in the antennal lobe, and in Kenyon cells (KCs) in the mushroom body. We show that the post-stimulus responses in ORN axons, PN dendrites, PN somata, and KC dendrites are odor-specific, but they are not predictive of the chemical identity of past olfactory stimuli. However, the post-stimulus responses in KC somata carry information about the identity of previous olfactory stimuli. These findings show that the Ca<sup>2+</sup> dynamics in KC somata could encode a sensory memory of odorant identity and thus might serve as a basis for associations between temporally separated stimuli.</p> 2018-07-10 08:38:20 Drosophila melanogaster olfaction sensory memory mushroom body Kenyon cells trace conditioning calcium imaging