Loss of paired-pulse facilitation at the corticostriatal synapse of the aged rat.
Changes in calcium (Ca2+) homeostasis have been proposed to contribute to the aging process. Paired-pulse facilitation, a form of synaptic enhancement that relies upon an accumulation of Ca2+ in the presynaptic terminal, was used to examine the effect of aging at the corticostriatal synapse. Intracellular recordings in striatal neurons from young rats demonstrated a consistent enhancement in the second of two synaptic responses evoked by stimulation of the corpus callosum. In contrast, neurons from aged rats showed a consistent depression of the second synaptic response at identical pairing intervals. These differences were not explained by an age-dependent increase in synaptic depression and demonstrate an alteration in the Ca(2+)-mediated process of presynaptic facilitation.
Walsh
J P
JP
Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles 90089-0191.
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D000375:Aging / Q000502:physiology*; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology; D003342:Corpus Striatum / Q000166:cytology / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D004594:Electrophysiology; D008297:Male; D009473:Neuronal Plasticity; D009474:Neurons / Q000502:physiology; D051381:Rats; D013569:Synapses / Q000502:physiology*