Animal Models of Declining Memory in the Aged: Short-term and Spatial Memory in the Aged Rat

Abstract

Short-term and spatial memory were studied in Fischer 344 rats ranging in age from 6 to 26 months of age. Spatial memory, as measured by performance in an 8-armed radial maze, declined gradually with age. In contrast, short-term memory, as measured by retention of previous choices in the spatial maze over short intervals and performance on a modified form of Konorski's discriminated delayed response task, did not decline differentially as a function of age. These findings may be comparable to those obtained in the aged human, who also show marked deficits in spatial memory and little change in primary memory under appropriate test conditions.

Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: Partial reversal by feeding acetyl- l -carnitine and/or R -α-lipoic acid

“…In the case of age-related human neurodegenerative diseases, such as Alzheimer's disease (AD), the deficit can be severe (1)(2)(3)(4). Memory loss is accompanied but not necessarily caused by accumulation of oxidative damage to lipids, proteins, and nucleic acids, and by mitochondrial decay, all of which can disrupt neuronal function (5)(6)(7)(8)(9)(10).…”

The Effect of Aging on Experience-Dependent Plasticity of Hippocampal Place Cells

“…In rodents, age deficits are observed in a variety of spatial learning and memory tasks (Barnes, 1979;Wallace et al, 1980;deToledoMorrell et al, 1984;Gage et al, 1984;Barnes and McNaughton, 1985;Gallagher et al, 1985;Gallagher and Pelleymonter, 1988). These effects cannot be f ully accounted for by sensory or motor deficits (Rapp et al, 1987;Gallagher and Pelleymonter, 1988;Gage et al, 1989), suggesting that alterations in hippocampal function with age may contribute to their etiology.…”

An evaluation of spatial information processing in aged rats.

“…Related to this intensified research effort is an increasing growth in the proportion of aged individuals in the population Because the incidence of various forms of cognitive deterioration is well documented to increase with increasing age (Botwimck, 1978), an important focus of current research is to delineate age-related changes in learning and memory in laboratory animals Such investigations may, therefore, highlight specific cognitive processes that are compromised in senescence, as well as provide insight into possible neural sites and mechanisms of senescent memory decline.In this context, a number of investigations utilizing a wide range of behavioral testing procedures have demonstrated that the performance of aged animals is impaired relative to young subjects (see Kubams & Zometzer, 1981, for a recent review) Perhaps the most consistent finding across investigations using rodents is that aged rats are impaired in tasks that young animals solve using spatial information Specifically, spatial information processing in aged rats has been studied using a number of testing procedures including the Barnes hole-board task (Barnes, 1979, Barnes, Nadel, & Homg, 1980, the 8-arm Correspondence concerning this article should be addressed to Peter R Rapp, who is now at The Salk Institute for Biological Sciences, Developmental Neurobiology Laboratory, P O Box 85800, San Diego, California 92138 radial maze (Barnes et al, 1980; Davis, Idowu, & Gibson, 1983 de Toledo-Morrell, Morell, Fleming, & Cohen, 1984, Gallagher, Bostock, & King, 1985, Wallace, Krauter, & Campbell, 1980, the 12-arm radial maze (Ingram, London, & Goodnck, 1981), as well as the Moms water maze (Gage, Dunnett, & Bjorklund, 1984). Despite differences in testing procedures and animal strains across these studies, old animals have exhibited acquisition deficits in each case These findings therefore suggest that spatial memory testing procedures may be particularly sensitive to changes in learning and memory in aged rats.…”