Calcium oscillations in freshly isolated neonatal rat cortical neurons.
OBJECTIVE
To investigate the mechanisms of intracellular calcium concentration ([Ca2+]i) oscillations in freshly isolated neonatal rat cortical neurons.


METHODS
Cortical neurons were isolated from neonatal rats 6-7 d after birth by enzymatic digestion. [Ca2+]i changes were measured in a microscopic calcium measurement system with Fura-2 as indicator.


RESULTS
In a total of 82 neurons recorded, 47 showed spontaneous [Ca2+]i oscillations. The spontaneous [Ca2+]i oscillations were dependent on [Ca2+]o. Removal of [Ca2+]o completely abolished spontaneous oscillations. Tetraethylammonium 1 mmol/L increased both the amplitude and frequency of calcium oscillations, whereas the frequency was increased by Cs+ 1 mmol/L. Ba2+ 1 mmol/L, in contrast, induced [Ca2+]i oscillations superimposed on a sustained phasic increase.


CONCLUSIONS
Spontaneous [Ca2+]i oscillation is an intrinsic property of neonatal rat cortical neurons. Potassium channels play an important role in the control of both the amplitude and frequency of [Ca2+]i oscillations in cortical neurons.
Liu
Xiao-Hong
XH
Institute of Cell Biology, Beijing Normal University, Beijing 100875, China.
Lü
Guo-Wei
GW
Cui
Zong-Jie
ZJ
D000818:Animals; D000831:Animals, Newborn; D017609:Barium Compounds / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology*; D002586:Cesium / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019789:Tetraethylammonium / Q000494:pharmacology*
D017609:Barium Compounds; D002712:Chlorides; D026902:Potassium Channel Blockers; D015221:Potassium Channels; C024986:barium chloride; D002586:Cesium; D019789:Tetraethylammonium; C028019:cesium chloride