title: Conditional modulation of spike-timing-dependent plasticity for olfactory learning.
abstract: Mushroom bodies are a well-known site for associative learning in insects. Yet the precise mechanisms that underlie plasticity there and ensure their specificity remain elusive. In locusts, the synapses between the intrinsic mushroom body neurons and their postsynaptic targets obey a Hebbian spike-timing-dependent plasticity (STDP) rule. Although this property homeostatically regulates the timing of mushroom body output, its potential role in associative learning is unknown. Here we show in vivo that pre-post pairing causing STDP can, when followed by the local delivery of a reinforcement-mediating neuromodulator, specify the synapses that will undergo an associative change. At these synapses, and there only, the change is a transformation of the STDP rule itself. These results illustrate the multiple actions of STDP, including a role in associative learning, despite potential temporal dissociation between the pairings that specify synaptic modification and the delivery of reinforcement-mediating neuromodulator signals.
authors.affiliation: Division of Biology, California Institute of Technology, Pasadena, California 91125, USA. stijn@caltech.edu
authors.forename: Stijn
authors.initials: S
authors.lastname: Cassenaer
authors.forename: Gilles
authors.initials: G
authors.lastname: Laurent
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006110:Grasshoppers / Q000187:drug effects / Q000502:physiology*; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009420:Nervous System / Q000166:cytology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009655:Octopamine / Q000494:pharmacology; D009812:Odorants / Q000032:analysis; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D009655:Octopamine