Role of the calcium-binding protein parvalbumin in short-term synaptic plasticity.
GABAergic (GABA = gamma-aminobutyric acid) neurons from different brain regions contain high levels of parvalbumin, both in their soma and in their neurites. Parvalbumin is a slow Ca(2+) buffer that may affect the amplitude and time course of intracellular Ca(2+) 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 Ca(2+) buffer EGTA (1 mM) rescues paired-pulse depression in PV-/- mice. These data show that parvalbumin potently modulates short-term synaptic plasticity.
Caillard
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O
Max-Planck-Institute for Biophysical Chemistry, D37 077 Göttingen, Germany. caillard@luminy.univ-mrs.fr
Moreno
H
H
Schwaller
B
B
Llano
I
I
Celio
M R
MR
Marty
A
A
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002531:Cerebellum / Q000187:drug effects / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D004558:Electric Stimulation; D004594:Electrophysiology / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D010320:Parvalbumins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D010320:Parvalbumins; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D004533:Egtazic Acid; D015763:2-Amino-5-phosphonovalerate