Modulation of neuronal [Ca2+]i by caffeine is altered with aging

Voltage-dependent calcium channels play an important role in controlling many neuronal processes such as neuronal excitability and synaptic transmission. Any slight alteration in intracellular calcium concentration ([Ca2+](i)) can have a considerable impact on various neuronal functions. The effects of caffeine on [Ca2+](i) were studied in CA1 hippocampal neurons of young (2 months) and old (24 months) C57BL mice. Fura 2-AM fluorescence photometry was used to measure [Ca2+](i) in the presence and absence of caffeine (100 mu M) in response to KCl (26 MM) application. Caffeine enhanced the peak [Ca2+](i) as compared to control solution in young mice (control: 325 +/- 8 nM, caffeine: 402 +/- 10 nM), but had no effect on the peak [Ca2+](i) in old mice (control: 222 +/- 6 nM, caffeine: 223 +/- 7 nM). These results indicate that caffeine can impact neuronal functions through the modification of [Ca2+](j). The lack of caffeine-induced modulation of [Ca2+](i) in old mice suggests that this role of caffeine has been compromised with aging. (c) 2006 ISDN. Published by Elsevier Ltd. All rights reserved.