title: Dendritic calcium spikes induce bi-directional synaptic plasticity in the lateral amygdala.
abstract: Postsynaptic induction of long-term potentiation (LTP) at cortical and thalamic afferent synapses onto lateral amygdala (LA) projection neurons not only involves NMDA receptor activation, but also depends on L-type voltage-dependent calcium channels (L-VDCCs). Here we show, using whole cell recordings and two-photon Ca2+ imaging, that L-VDCCs contribute to the induction of dendritic Ca2+ spikes in LA projection neurons. Dendritic Ca2+ spikes can be induced in the absence of sodium spikes by supra-threshold somatic depolarization or by pairing sub-threshold depolarization with synaptic stimulation. Moreover, synaptic induction of Ca2+ spikes is facilitated by R-VDCCs in a pathway-specific manner. Once induced, dendritic Ca2+ spikes propagate into large parts of the dendritic tree. We show that pairing synaptic stimulation with single dendritic Ca2+ spikes can induce bi-directional plasticity, the sign of which might be determined by the anatomical location of active synaptic inputs relative to the spike initiation zone. These data suggest an important role for dendritic Ca2+ spikes in dendritic integration and provide a mechanism by which local synaptic activity may influence global dendritic integration in LA projection neurons.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
authors.forename: Yann
authors.initials: Y
authors.lastname: Humeau
authors.forename: Andreas
authors.initials: A
authors.lastname: Lüthi
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D000679:Amygdala / Q000166:cytology* / Q000502:physiology; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003712:Dendrites / Q000378:metabolism*; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D066298:In Vitro Techniques; D008012:Lidocaine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009434:Neural Pathways / Q000502:physiology / Q000528:radiation effects; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure; D009532:Nickel / Q000494:pharmacology; D018408:Patch-Clamp Techniques / Q000379:methods; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D013111:Spider Venoms / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D014700:Verapamil / Q000494:pharmacology
chemical_list: D000779:Anesthetics, Local; D002121:Calcium Channel Blockers; C115521:SNX 482; D013111:Spider Venoms; C012647:QX-314; C022838:nickel chloride; D009532:Nickel; D008012:Lidocaine; D014700:Verapamil; D002118:Calcium