Comparison of low-threshold Ca2+ currents in the hippocampal CA1 neurons among the newborn, adult and aged rats.

The electrical and pharmacological properties of the low-threshold Ca2+ current were compared among the newborn, adult and aged rats using the isolated hippocampal CA1 pyramidal neurons. The current-voltage relationship and the time constant of the decay phase of the low-threshold Ca2+ current in adult and aged rats were similar to those in newborn rats. The low-threshold Ca2+ current of adult and aged rats was also sensitive to nicardipine, a dihydropyridine derivative, same as that of newborn rats. We concluded that the nature of low-threshold Ca2+ current in the rat hippocampal CA1 pyramidal neurons is not affected by the aging.