Cytoplasmic calcium buffer, calbindin-D28k, is regulated by excitatory amino acids.
Excessive intracellular calcium in neurones is thought to underlie the pathophysiology of several neurodegenerative diseases. An extensively studied animal model is the neurotoxic increases in intracellular Ca2+ induced by excitatory amino acid. We report here that the calcium-binding protein, calbindin-D28k, increases rapidly in Purkinje cells of rat cerebellar slices superfused with excitatory and excitotoxic concentrations of glutamate or its analogue, kainic acid. The increase is reversible and reproducible, is blocked by CNQX and is independent of Ca2+ influx. These results indicate that calbindin containing neurones can regulate their Ca2+ buffering capacity in response to a specific agonist and this regulation is not mediated by cytosolic calcium increases.
Batini
C
C
Laboratoire de physiologie de la motricité, CNRS, Université Pierre et Marie Curie, CHU Pitié-Salpêtrière, Paris, France.
Palestini
M
M
Thomasset
M
M
Vigot
R
R
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000596:Amino Acids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D064092:Calbindin 1; D064026:Calbindins; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D002525:Cerebellar Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011689:Purkinje Cells / Q000187:drug effects / Q000378:metabolism; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
D000596:Amino Acids; C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D011810:Quinoxalines; D064030:S100 Calcium Binding Protein G; D018698:Glutamic Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D007608:Kainic Acid; D002118:Calcium