HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 551/1/13    most recent jphysiol.2002.035824v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schmidt, H. Articles by Eilers, J. Search for Related Content PubMed PubMed Citation Articles by Schmidt, H. Articles by Eilers, J.

Mutational analysis of dendritic Ca²⁺ kinetics in rodent Purkinje cells: role of parvalbumin and calbindin D_28k

Hartmut Schmidt *†, Klaus M. Stiefel *, Peter Racay ‡, Beat Schwaller ‡ and Jens Eilers*†

The mechanisms governing the kinetics of climbing fibre-mediated Ca²⁺ transients in spiny dendrites of cerebellar Purkinje cells (PCs) were quantified with high-resolution confocal Ca²⁺ imaging. Ca²⁺ dynamics in parvalbumin (PV^-/-) and parvalbumin/calbindin D_28k null-mutant (PV/CB^-/-) mice were compared with responses in wild-type (WT) animals. In the WT, Ca²⁺ transients in dendritic shafts were characterised by double exponential decay kinetics that were not due to buffered Ca²⁺ diffusion or saturation of the indicator dye. Ca²⁺ transients in PV^-/- PCs reached the same peak amplitude as in the WT but the biphasic nature of the decay was less pronounced, an effect that could be attributed to PV's slow binding kinetics. In contrast, peak amplitudes in PV/CB^-/- PCs were about two times higher than in the WT and the decay became nearly monophasic. Numerical simulations indicate that the residual deviation from a single exponential decay in PV/CB^-/- is due to saturation of the Ca²⁺ indicator dye. Furthermore, the simulations imply that the effect of uncharacterised endogenous Ca²⁺ binding proteins is negligible, that buffered diffusion and dye saturation significantly affects spineous Ca²⁺ transients but not those in the dendritic shafts, and that neither CB nor PV undergoes saturation in spines or dendrites during climbing fibre-evoked Ca²⁺ transients. Calbindin's medium-affinity binding sites are fast enough to reduce the peak amplitude of the Ca²⁺ signal. However, similar to PV, delayed binding by CB leads to biphasic Ca²⁺ decay kinetics. Our results suggest that the distinct kinetics of PV and CB underlie the biphasic kinetics of synaptically evoked Ca²⁺ transients in dendritic shafts of PCs.

This article has been cited by other articles:

				D. Orduz and I. Llano Recurrent axon collaterals underlie facilitating synapses between cerebellar Purkinje cells PNAS, November 6, 2007; 104(45): 17831 - 17836. [Abstract] [Full Text] [PDF]

				D. V. Sarkisov, S. E. Gelber, J. W. Walker, and S. S.-H. Wang Synapse Specificity of Calcium Release Probed by Chemical Two-photon Uncaging of Inositol 1,4,5-Trisphosphate J. Biol. Chem., August 31, 2007; 282(35): 25517 - 25526. [Abstract] [Full Text] [PDF]

				A. Nemri and N. Ghisovan Dendritic spines: it takes two to make an impression J. Physiol., July 1, 2007; 582(1): 15 - 16. [Full Text] [PDF]

				H. Schmidt, S. Kunerth, C. Wilms, R. Strotmann, and J. Eilers Spino-dendritic cross-talk in rodent Purkinje neurons mediated by endogenous Ca2+-binding proteins J. Physiol., June 1, 2007; 581(2): 619 - 629. [Abstract] [Full Text] [PDF]

				M. Muller, F. Felmy, B. Schwaller, and R. Schneggenburger Parvalbumin Is a Mobile Presynaptic Ca2+ Buffer in the Calyx of Held that Accelerates the Decay of Ca2+ and Short-Term Facilitation J. Neurosci., February 28, 2007; 27(9): 2261 - 2271. [Abstract] [Full Text] [PDF]

				V. Matveev, R. Bertram, and A. Sherman Residual Bound Ca2+ Can Account for the Effects of Ca2+ Buffers on Synaptic Facilitation J Neurophysiol, December 1, 2006; 96(6): 3389 - 3397. [Abstract] [Full Text] [PDF]

				M. Canepari and D. Ogden Kinetic, pharmacological and activity-dependent separation of two Ca2+ signalling pathways mediated by type 1 metabotropic glutamate receptors in rat Purkinje neurones J. Physiol., May 15, 2006; 573(1): 65 - 82. [Abstract] [Full Text] [PDF]

				L. Kreiner and A. Lee Endogenous and Exogenous Ca2+ Buffers Differentially Modulate Ca2+-dependent Inactivation of CaV2.1 Ca2+ Channels J. Biol. Chem., February 24, 2006; 281(8): 4691 - 4698. [Abstract] [Full Text] [PDF]

				N. Hernjak, B. M. Slepchenko, K. Fernald, C. C. Fink, D. Fortin, I. I. Moraru, J. Watras, and L. M. Loew Modeling and Analysis of Calcium Signaling Events Leading to Long-Term Depression in Cerebellar Purkinje Cells Biophys. J., December 1, 2005; 89(6): 3790 - 3806. [Abstract] [Full Text] [PDF]

				J.-W. Lin, Q. Fu, and T. Allana Probing the Endogenous Ca2+ Buffers at the Presynaptic Terminals of the Crayfish Neuromuscular Junction J Neurophysiol, July 1, 2005; 94(1): 377 - 386. [Abstract] [Full Text] [PDF]

				H. Schmidt, B. Schwaller, and J. Eilers Calbindin D28k targets myo-inositol monophosphatase in spines and dendrites of cerebellar Purkinje neurons PNAS, April 19, 2005; 102(16): 5850 - 5855. [Abstract] [Full Text] [PDF]

				T. Collin, M. Chat, M. G. Lucas, H. Moreno, P. Racay, B. Schwaller, A. Marty, and I. Llano Developmental Changes in Parvalbumin Regulate Presynaptic Ca2+ Signaling J. Neurosci., January 5, 2005; 25(1): 96 - 107. [Abstract] [Full Text] [PDF]

				C. I. Turnbull, K. Looi, J. E. Mangum, M. Meyer, R. J. Sayer, and M. J. Hubbard Calbindin Independence of Calcium Transport in Developing Teeth Contradicts the Calcium Ferry Dogma J. Biol. Chem., December 31, 2004; 279(53): 55850 - 55854. [Abstract] [Full Text] [PDF]

				S. L. Dargan, B. Schwaller, and I. Parker Spatiotemporal patterning of IP3-mediated Ca2+ signals in Xenopus oocytes by Ca2+-binding proteins J. Physiol., April 15, 2004; 556(2): 447 - 461. [Abstract] [Full Text] [PDF]