Activity-dependent survival of rat cerebellar granule neurons is not associated with sustained elevation of intracellular Ca2+.
Ca2+ plays a pivotal role for the activity-dependent survival of neurons. In primary culture of cerebellar granule neurons, we found that there is no significant difference in intracellular Ca2+ level in the survival-promoting condition (cultures in the presence of 25 mM KCl) and that in the apoptosis-inducing condition (cultures in the presence of 5 mM KCl). This was not due to the inactivation of voltage-dependent L-type Ca2+ channels in the survival-promoting condition, but due to the enhanced rate of the influx and the efflux of Ca2+ in the survival-promoting condition compared to that in the apoptosis-inducing condition. These results suggest that the activity-dependent survival of the granule neurons is not associated with sustained rise of intracellular Ca2+ but associated with the enhanced turnover rate of Ca2+.
Ono
T
T
Department of Molecular Biology, The Tokyo Metropolitan Institute of Medical Science, Bunkyo-ku, Japan. ono@rinshoken.or.jp
Kudo
Y
Y
Kohara
K
K
Kawashima
S
S
Ogura
A
A
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D004594:Electrophysiology; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009543:Nifedipine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats
D002121:Calcium Channel Blockers; D007476:Ionophores; D015759:Ionomycin; D011189:Potassium Chloride; D009543:Nifedipine; D002118:Calcium