NMDA depolarizations and long-term potentiation are reduced in the aged rat neocortex.
N-Methyl-D-aspartate (NMDA) responses were recorded intracellularly in layer V neocortical neurons in in vitro slices taken from young (4-6 months) and aged (27-29 months) Fischer 344 rats. Increasing amounts of NMDA produced membrane depolarizations in both groups of cells. The regression analysis showed significantly reduced sensitivity to NMDA in old neurons compared to young. A significant long-term potentiation of the field potential evoked by subcortical white matter stimulation was present in young but not in old slices. These results suggest that aging results in a decreased sensitivity to NMDA and impaired synaptic plasticity in the neocortex.
Baskys
A
A
Playfair Neuroscience Unit, Toronto Western Hospital, Ont. Canada.
Reynolds
J N
JN
Carlen
P L
PL
D000375:Aging / Q000502:physiology*; D000544:Alzheimer Disease / Q000503:physiopathology*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects*; D004195:Disease Models, Animal; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
D016202:N-Methylaspartate