Structural long-term changes at mushroom body input synapses.
How does the sensory environment shape circuit organization in higher brain centers? Here we have addressed the dependence on activity of a defined circuit within the mushroom body of adult Drosophila. This is a brain region receiving olfactory information and involved in long-term associative memory formation. The main mushroom body input region, named the calyx, undergoes volumetric changes correlated with alterations of experience. However, the underlying modifications at the cellular level remained unclear. Within the calyx, the clawed dendritic endings of mushroom body Kenyon cells form microglomeruli, distinct synaptic complexes with the presynaptic boutons of olfactory projection neurons. We developed tools for high-resolution imaging of pre- and postsynaptic compartments of defined calycal microglomeruli. Here we show that preventing firing of action potentials or synaptic transmission in a small, identified fraction of projection neurons causes alterations in the size, number, and active zone density of the microglomeruli formed by these neurons. These data provide clear evidence for activity-dependent organization of a circuit within the adult brain of the fly.
Department of Molecular Neurobiology, Dendrite Differentiation Group, Max Planck Institute (MPI) of Neurobiology, Munich-Martinsried 82152, Germany.
Malte C
MC
Kremer
Frauke
F
Christiansen
Florian
F
Leiss
Moritz
M
Paehler
Stephan
S
Knapek
Till F M
TF
Andlauer
Friedrich
F
Förstner
Peter
P
Kloppenburg
Stephan J
SJ
Sigrist
Gaia
G
Tavosanis
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004330:Drosophila / Q000502:physiology* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D024521:Mushroom Bodies / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000502:physiology; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012903:Smell; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology
C510146:BRP protein, Drosophila; D029721:Drosophila Proteins; C102352:Ork1 protein, Drosophila; D015221:Potassium Channels; D011993:Recombinant Fusion Proteins