title: Requirement for nuclear calcium signaling in Drosophila long-term memory.
abstract: Calcium is used throughout evolution as an intracellular signal transducer. In the mammalian central nervous system, calcium mediates the dialogue between the synapse and the nucleus that is required for transcription-dependent persistent neuronal adaptations. A role for nuclear calcium signaling in similar processes in the invertebrate brain has yet to be investigated. Here, we show by in vivo calcium imaging of adult brain neurons of the fruit fly Drosophila melanogaster, that electrical foot shocks used in olfactory avoidance conditioning evoked transient increases in cytosolic and nuclear calcium concentrations in neurons. These calcium signals were detected in Kenyon cells of the flies' mushroom bodies, which are sites of learning and memory related to smell. Acute blockade of nuclear calcium signaling during conditioning selectively and reversibly abolished the formation of long-term olfactory avoidance memory, whereas short-term, middle-term, or anesthesia-resistant olfactory memory remained unaffected. Thus, nuclear calcium signaling is required in flies for the progression of memories from labile to transcription-dependent long-lasting forms. These results identify nuclear calcium as an evolutionarily conserved signal needed in both invertebrate and vertebrate brains for transcription-dependent memory consolidation.
authors: Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, INF 364, 69120 Heidelberg, Germany.
authors: Jan-Marek
authors: JM
authors: Weislogel
authors: C Peter
authors: CP
authors: Bengtson
authors: Michaela K
authors: MK
authors: Müller
authors: Jan N
authors: JN
authors: Hörtzsch
authors: Martina
authors: M
authors: Bujard
authors: Christoph M
authors: CM
authors: Schuster
authors: Hilmar
authors: H
authors: Bading
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000831:Animals, Newborn; D001362:Avoidance Learning / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004558:Electric Stimulation; D018869:Heat-Shock Response / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D015151:Immunoblotting; D057567:Memory, Long-Term / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D024521:Mushroom Bodies / Q000378:metabolism / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D009833:Olfactory Pathways / Q000378:metabolism / Q000502:physiology
chemical_list: D002118:Calcium