Calcium channel types mediating synaptic transmission during aging.

The effects of omega-conotoxin (CTX) GVIA, omega-agatoxin (Aga) IVA, and the dihydropyridine nicardipine were studied on synaptic transmission in the hippocampus during aging. Field excitatory postsynaptic potentials (fEPSPs) were recorded in the CA1 region in slices from young and aged Fischer 344 rats. Peptide toxins reduced synaptic transmissions similarly in both age groups while nicardipine showed no effect. These results suggests that the well documented age-related changes in synaptic transmissions in the hippocampus cannot be explained by changes in the types of Ca2+ channel mediating synaptic transmission.