title: Age-associated alterations of hippocampal place cells are subregion specific.
abstract: Aging is associated with spatial memory impairments and with deficient encoding of information by the hippocampus. In young adult rats, recent studies on the firing properties of hippocampal neurons have emphasized the importance of the CA3 subregion in the rapid encoding of new spatial information. Here, we compared the spatial firing patterns of CA1 and CA3 neurons in aged memory-impaired rats with those of young rats as they explored familiar and novel environments. We found that CA1 place cells in aged and young rats had similar firing characteristics in the familiar and novel environments. In contrast, aged CA3 place cells had higher firing rates in general and failed to change their firing rates and place fields as much as CA3 cells of young rats when the rats were introduced to a novel environment. Thus, aged CA3 cells failed to rapidly encode new spatial information compared with young CA3 cells. These data suggest an important and selective contribution of CA3 dysfunction to age-related memory impairment.
authors: Department of Neuroscience and Neurology, University of Kuopio, Kuopio 70211, Finland. Iain.Wilson@uku.fi
authors: Iain A
authors: IA
authors: Wilson
authors: Sami
authors: S
authors: Ikonen
authors: Michela
authors: M
authors: Gallagher
authors: Howard
authors: H
authors: Eichenbaum
authors: Heikki
authors: H
authors: Tanila
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000375:Aging / Q000473:pathology*; D000818:Animals; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008569:Memory Disorders / Q000473:pathology* / Q000503:physiopathology; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000502:physiology*