TY - JOUR T1 - Functional Coupling between mGluR1 and Ca<sub>v</sub>3.1 T-Type Calcium Channels Contributes to Parallel Fiber-Induced Fast Calcium Signaling within Purkinje Cell Dendritic Spines JF - The Journal of Neuroscience JO - J. Neurosci. SP - 9668 LP - 9682 DO - 10.1523/JNEUROSCI.0362-09.2009 VL - 29 IS - 31 AU - Michael E. Hildebrand AU - Philippe Isope AU - Taisuke Miyazaki AU - Toshitaka Nakaya AU - Esperanza Garcia AU - Anne Feltz AU - Toni Schneider AU - Jürgen Hescheler AU - Masanobu Kano AU - Kenji Sakimura AU - Masahiko Watanabe AU - Stéphane Dieudonné AU - Terrance P. Snutch Y1 - 2009/08/05 UR - http://www.jneurosci.org/content/29/31/9668.abstract N2 - T-type voltage-gated calcium channels are expressed in the dendrites of many neurons, although their functional interactions with postsynaptic receptors and contributions to synaptic signaling are not well understood. We combine electrophysiological and ultrafast two-photon calcium imaging to demonstrate that mGluR1 activation potentiates cerebellar Purkinje cell Cav3.1 T-type currents via a G-protein- and tyrosine-phosphatase-dependent pathway. Immunohistochemical and electron microscopic investigations on wild-type and Cav3.1 gene knock-out animals show that Cav3.1 T-type channels are preferentially expressed in Purkinje cell dendritic spines and colocalize with mGluR1s. We further demonstrate that parallel fiber stimulation induces fast subthreshold calcium signaling in dendritic spines and that the synaptic Cav3.1-mediated calcium transients are potentiated by mGluR1 selectively during bursts of excitatory parallel fiber inputs. Our data identify a new fast calcium signaling pathway in Purkinje cell dendritic spines triggered by short burst of parallel fiber inputs and mediated by T-type calcium channels and mGluR1s. ER -