RT Journal Article SR Electronic T1 Activity-Dependent Compartmentalized Regulation of Dendritic Ca2+ Signaling in Hippocampal Interneurons JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 4658 OP 4663 DO 10.1523/JNEUROSCI.0493-09.2009 VO 29 IS 14 A1 Topolnik, Lisa A1 Chamberland, Simon A1 Pelletier, Joe-Guillaume A1 Ran, Israeli A1 Lacaille, Jean-Claude YR 2009 UL http://www.jneurosci.org/content/29/14/4658.abstract AB Activity-dependent regulation of synaptic inputs in neurons is controlled by highly compartmentalized and dynamic dendritic calcium signaling. Among multiple Ca2+ mechanisms operating in neuronal dendrites, voltage-sensitive Ca2+ channels (VSCCs) represent a major source of Ca2+ influx; however, their use-dependent implication, regulation, and function in different types of central neurons remain widely unknown. Using two-photon microscopy to probe Ca2+ signaling in dendrites of hippocampal oriens/alveus interneurons, we found that intense synaptic activity or local activation of mGluR5 induced long-lasting potentiation of action potential evoked Ca2+ transients. This potentiation of dendritic Ca2+ signaling required mGluR5-induced intracellular Ca2+ release and PKC activation and was expressed as a selective compartmentalized potentiation of L-type VSCCs. Thus, in addition to mGluR1a-dependent synaptic plasticity, hippocampal interneurons in the feedback inhibitory circuit demonstrate a novel form of mGluR5-induced dendritic plasticity. Given an implication of L-type VSCCs in the induction of Hebbian LTP at interneuron excitatory synapses, their activity-dependent regulation may represent a powerful mechanism for regulating synaptic plasticity.