Figure 5.
Schematic model of proposed interactions of L-VGCC and altered CICR in driving Ca2+-related processes in the hippocampus of young (A) and aged (B) animals. The increased L-VGCC activity and enhanced CICR are in series, amplifying the impact of Ca2+ influx on multiple functions. The thickness of arrows schematically represents the relative weight of contribution to [Ca2+]i levels and responses. Despite similar spike-mediated depolarization, with aging, the contribution is increased at several stages. The dashed arrows indicate a possible direct parallel contribution of L-VGCCs to [Ca2+]i.