Role of the calcium-binding protein parvalbumin in short-term synaptic plasticity

Role of the calcium-binding protein parvalbumin in short-term synaptic plasticity

^*Max-Planck-Institute for Biophysical Chemistry, D37 077 Göttingen, Germany; ^‡New York University, New York, NY 10016; and ^§Institute of Histology and General Embryology, CH 1705 Fribourg, Switzerland

Edited by Erwin Neher, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany, and approved September 18, 2000 (received for review August 2, 2000)

Abstract

GABAergic (GABA = γ-aminobutyric acid) neurons from different brain regions contain high levels of parvalbumin, both in their soma and in their neurites. Parvalbumin is a slow Ca²⁺ buffer that may affect the amplitude and time course of intracellular Ca²⁺ transients in terminals after an action potential, and hence may regulate short-term synaptic plasticity. To test this possibility, we have applied paired-pulse stimulations (with 30- to 300-ms intervals) at GABAergic synapses between interneurons and Purkinje cells, both in wild-type (PV+/+) mice and in parvalbumin knockout (PV−/−) mice. We observed paired-pulse depression in PV+/+ mice, but paired-pulse facilitation in PV−/− mice. In paired recordings of connected interneuron-Purkinje cells, dialysis of the presynaptic interneuron with the slow Ca²⁺ buffer EGTA (1 mM) rescues paired-pulse depression in PV−/− mice. These data show that parvalbumin potently modulates short-term synaptic plasticity.

Footnotes

↵ † To whom reprint requests should be addressed at the present address: Institut de Neurobiologie de la Méditerranée (INMED), Institut National de la Santé et de la Recherche Médicale U29, Avenue de Luminy, B.P. 13, 13273 Marseille Cedex 09, France. E-mail: caillard{at}luminy.univ-mrs.fr.
This paper was submitted directly (Track II) to the PNAS office.
↵ ¶ Farre Castany, M. A., Mariethoz, C., Tetko, I. V., Schwaller, B., Celio, M., Hunzicker, W., Meyer, M. & Villa, A. E. P. (2000) Eur. J. Neurosci. 12, Suppl. 11, 172 (abstr.).
↵ ‖ Schwaller, B., Villa, A., Tandon, P., Tetko, I. V., Silveira, D. C. & Celio, M. R. (2000) Eur. J. Neurosci. 12, Suppl. 11, 106 (abstr.).
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.230362997.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.230362997
Abbreviations:

PV+/+,

wild type;

PV−/−,

parvalbumin knockout;

PV,

parvalbumin;

PPR,

paired-pulse ratio;

eIPSC,

evoked inhibitory postsynaptic current;

GABA,

γ-aminobutyric acid;

ISI,

interstimulus interval;

[Mg2+]i,

intracellular Mg2+ concentration