Increase in single L-type calcium channels in hippocampal neurons during aging

Voltage-activated calcium (Ca²⁺) influx is increased in mammalian CAt hippocampal neurons during aging. However, the molecular basis for this elevation is not known. The partially dissociated hippocampal ('zipper') slice preparation was used to analyze single Ca²⁺ channel activity in CA1 neurons of adult and aged rats. Total L-type Ca²⁺ channel activity in patches was found to increase with aging, primarily because of an increase in the density of functional channels. Learning in aged animals was inversely correlated with channel density. This increase in functional Ca²⁺ channels with aging could underlie the vulnerability of neurons to age-associated neurodegenerative conditions.