Calcium oscillations in freshly isolated neonatal rat cortical neurons.
Abstract
AIM: 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.
CONCLUSION: 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.
Keywords:
([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.
CONCLUSION: 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.