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Paul Yarowsky - One of the best experts on this subject based on the ideXlab platform.
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Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
Behavioural brain research, 1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction.
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Short communication Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction. © 1998 Elsevier Science B.V.
Gregory E. Demas - One of the best experts on this subject based on the ideXlab platform.
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Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
Behavioural brain research, 1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction.
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Short communication Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction. © 1998 Elsevier Science B.V.
Karyn M. Frick - One of the best experts on this subject based on the ideXlab platform.
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male mice exhibit better spatial working and Reference Memory than females in a water escape radial arm maze task
Brain Research, 2003Co-Authors: Jodi E. Gresack, Karyn M. FrickAbstract:The present study examined sex differences in spatial working and Reference Memory in C57BL/6 mice. Males and females were tested in a version of the spatial 8-arm radial arm maze in which the motivating stimulus was escape from water. To test spatial working Memory, four arms were baited with submerged escape platforms, each of which was removed after it was found. Four arms that never contained platforms assessed spatial Reference Memory. In addition to determining the number of working Memory and Reference Memory errors made in each session, working Memory errors made in each trial were analyzed to examine performance as the number of arms to be remembered (i.e. the working Memory load) increased. Males committed significantly fewer working Memory and Reference Memory errors than females throughout testing. Within a session, males committed fewer working Memory errors than females as the working Memory load increased. These sex differences were particularly evident during task acquisition. The data indicate that male C57BL/6 mice learn both the working and Reference Memory components of a water-escape motivated radial arm maze task better than female mice.
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estrogen replacement improves spatial Reference Memory and increases hippocampal synaptophysin in aged female mice
Neuroscience, 2002Co-Authors: Karyn M. Frick, Stephanie M Fernandez, S C BulinskiAbstract:Abstract Estrogen deficiency during menopause is often associated with Memory dysfunction. However, inconsistencies regarding the ability of estrogen to improve Memory in menopausal women highlight the need to evaluate, in a controlled animal model, the potential for estrogen to alleviate age-related mnemonic decline. The current study tested whether estrogen could ameliorate spatial Reference Memory decline in aged female mice. At the conclusion of testing, levels of the presynaptic protein synaptophysin, and activities of the synthetic enzymes for acetylcholine and GABA, were measured in the hippocampus and neocortex. Aged (27–28-month-old) female C57BL/6 mice were given daily subcutaneous injections of 1 μg or 5 μg of β-estradiol-3-benzoate dissolved in sesame oil. Control mice received daily injections of sesame oil or no injections. Estradiol treatment began 5 days prior to behavioral testing and continued throughout testing. Spatial and non-spatial Memory were assessed in the Morris water maze. The 5 μg dose of estradiol significantly improved spatial learning and Memory in aged females. The performance of 5 μg females improved significantly more rapidly than that of control females; estradiol-treated females performed at asymptotic levels by session 2. Furthermore, 5 μg females exhibited a more robust spatial bias than controls during probe trials. In contrast, 1 μg of estradiol did not improve spatial task performance. Neither dose affected performance of the non-spatial task. In the hippocampus, synaptophysin was increased in 5 μg females relative to controls. Estrogen did not affect enzyme activities in either brain region. This study is the first to examine the effects of estrogen replacement on spatial Reference Memory and synaptophysin expression in aged post-estropausal female rodents. The results suggest that: (1) estrogen can profoundly improve spatial Reference Memory in aged females, and (2) this improvement may be related to increased hippocampal synaptic plasticity, but not modulation of the synthetic enzymes for acetylcholine and GABA.
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Spatial Reference Memory and neocortical neurochemistry vary with the estrous cycle in C57BL/6 mice.
Behavioral neuroscience, 2001Co-Authors: Karyn M. Frick, Joanne Berger-sweeneyAbstract:Estrous cycle-related variations of spatial Reference Memory and neurochemistry in intact female mice were examined. Spatial Reference Memory was tested in cycling females, ovariectomized (OVX) females, and males by using a 1-day water maze protocol. Choline acetyltransferase (ChAT) and glutamic acid decarboxylase (GAD) activities were measured in the hippocampus and neocortex. Estrus females exhibited worse spatial acquisition and 30-min retention than did proestrus and metestrus females, higher neocortical ChAT activity than proestrus females, and higher neocortical GAD activity than OVX females and males. Neocortical, rather than hippocampal, neurochemistry was more sensitive to hormonal modulation, suggesting that hormonal mediation of neocortical function may play a critical role in regulating spatial Reference Memory in female mice.
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Reference Memory, anxiety and estrous cyclicity in C57BL/6NIA mice are affected by age and sex.
Neuroscience, 2000Co-Authors: Karyn M. Frick, L A Burlingame, J A Arters, Joanne Berger-sweeneyAbstract:Age-related changes in learning and Memory are common in rodents. However, direct comparisons of the effects of aging on learning and Memory in both males and females are lacking. The present study examined whether Memory deteriorates with increasing age in C57BL/6NIA mice, and whether age-related changes in learning and Memory are similar in both sexes. Male and female mice (five, 17 and 25 months of age) were tested in a battery of behavioral tasks including the Morris water maze (spatial and non-spatial Reference Memory), simple odor discrimination (olfactory Reference Memory), plus maze (anxiety/exploration), locomotor activity, and basic reflexes. Five-month-old mice learned the water maze and odor discrimination tasks rapidly. Relative to five-month-old mice, 25-month-old mice exhibited impaired spatial and olfactory Reference Memory, but intact non-spatial Reference Memory. The spatial Reference Memory of 17-month-old mice was also impaired, but less so than 25-month mice. Seventeen-month-old mice exhibited intact non-spatial (visual and olfactory) Reference Memory. Five and 25-month-old mice had similar levels of plus maze exploration and locomotor activity, whereas 17-month-old mice were more active than both groups and were slightly less exploratory than five-month-old mice. Although sex differences were not observed in the five- and 25-month groups, 17-month-old females exhibited more impaired spatial Reference Memory and increased anxiety relative to 17-month-old males. Estrous cycling in females deteriorated significantly with increased age; all 25-month-old females had ceased cycling and 80% of 17-month-old females displayed either irregular or absent estrous cycling. This study is the first to directly compare age-related mnemonic decline in male and female mice. The results suggest that: (i) aged mice exhibit significant deficits in spatial and olfactory Reference Memory relative to young mice, whereas middle-aged mice exhibit only a moderate spatial Memory deficit and; (ii) spatial Reference Memory decline begins at an earlier age in females than in males, a finding that may be related to the cessation of estrous cycling.
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Reference Memory anxiety and estrous cyclicity in c57bl 6nia mice are affected by age and sex
Neuroscience, 1999Co-Authors: Karyn M. Frick, L A Burlingame, J A Arters, Joanne BergersweeneyAbstract:Abstract Age-related changes in learning and Memory are common in rodents. However, direct comparisons of the effects of aging on learning and Memory in both males and females are lacking. The present study examined whether Memory deteriorates with increasing age in C57BL/6NIA mice, and whether age-related changes in learning and Memory are similar in both sexes. Male and female mice (five, 17 and 25 months of age) were tested in a battery of behavioral tasks including the Morris water maze (spatial and non-spatial Reference Memory), simple odor discrimination (olfactory Reference Memory), plus maze (anxiety/exploration), locomotor activity, and basic reflexes. Five-month-old mice learned the water maze and odor discrimination tasks rapidly. Relative to five-month-old mice, 25-month-old mice exhibited impaired spatial and olfactory Reference Memory, but intact non-spatial Reference Memory. The spatial Reference Memory of 17-month-old mice was also impaired, but less so than 25-month mice. Seventeen-month-old mice exhibited intact non-spatial (visual and olfactory) Reference Memory. Five and 25-month-old mice had similar levels of plus maze exploration and locomotor activity, whereas 17-month-old mice were more active than both groups and were slightly less exploratory than five-month-old mice. Although sex differences were not observed in the five- and 25-month groups, 17-month-old females exhibited more impaired spatial Reference Memory and increased anxiety relative to 17-month-old males. Estrous cycling in females deteriorated significantly with increased age; all 25-month-old females had ceased cycling and 80% of 17-month-old females displayed either irregular or absent estrous cycling. This study is the first to directly compare age-related mnemonic decline in male and female mice. The results suggest that: (i) aged mice exhibit significant deficits in spatial and olfactory Reference Memory relative to young mice, whereas middle-aged mice exhibit only a moderate spatial Memory deficit and; (ii) spatial Reference Memory decline begins at an earlier age in females than in males, a finding that may be related to the cessation of estrous cycling.
Randy J. Nelson - One of the best experts on this subject based on the ideXlab platform.
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Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
Behavioural brain research, 1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction.
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Short communication Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction. © 1998 Elsevier Science B.V.
Bruce K. Krueger - One of the best experts on this subject based on the ideXlab platform.
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Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
Behavioural brain research, 1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction.
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Short communication Impaired spatial working and Reference Memory in segmental trisomy (Ts65Dn) mice
1998Co-Authors: Gregory E. Demas, Randy J. Nelson, Bruce K. Krueger, Paul YarowskyAbstract:To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and Reference Memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of Reference Memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working Memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and Reference Memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction. © 1998 Elsevier Science B.V.
