Diminished calcium currents in aged hippocampal dentate gyrus granule neurones.
Voltage-dependent calcium currents in hippocampal dentate gyrus granule neurons of young adult (4-6 months) and aged (24-26 months) Fischer 344 rats have been examined using single-electrode voltage-clamp techniques. Calcium currents, especially a high threshold slowly inactivating L-type current, were significantly depressed in neurons obtained from aged animals. Furthermore, these age-dependent changes could be reversed by intracellular injection of the calcium chelator, ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). These results are in agreement with the hypothesis that aging results in a persistent increase in the free cytoplasmic calcium concentration in mammalian central neurons.
Reynolds
J N
JN
Playfair Neuroscience Unit, Toronto Western Hospital, Addiction Research Foundation, Ont., Canada.
Carlen
P L
PL
D000200:Action Potentials / Q000187:drug effects; D000375:Aging / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D051381:Rats; D011916:Rats, Inbred F344
D004533:Egtazic Acid; D002118:Calcium