The Experts below are selected from a list of 16296 Experts worldwide ranked by ideXlab platform
Max S. Cynader - One of the best experts on this subject based on the ideXlab platform.
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columnar distribution of serotonin dependent plasticity within Kitten striate cortex
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Ljubomir Kojic, Robert M Douglas, Richard H Dyck, Joanne A Matsubara, Max S. CynaderAbstract:Recent studies have identified the potential for an important role for serotonin (5-HT) receptors in the developmental plasticity of the Kitten visual cortex. 5-HT2C receptors are transiently expressed in a patchy fashion in the visual cortex of Kittens between 30–80 days of age complementary to patches demarcated by cytochrome oxidase staining. 5-HT, operating via 5-HT2C receptors, increases cortical synaptic plasticity as assessed both in brain slices and in vivo. Herein, we report that bath application of 5-HT substantially increases the probability of long-term potentiation within 5-HT2C receptor-rich zones of cortex, but this effect is not observed in the 5-HT2C receptor-poor zones. Instead, in these zones, 5-HT application increases the probability of long-term depression. These location-specific effects of 5-HT may promote the formation of compartment-specific cortical responses.
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serotonin facilitates synaptic plasticity in Kitten visual cortex an in vitro study
Developmental Brain Research, 1997Co-Authors: Ljubomir Kojic, Robert M Douglas, Max S. CynaderAbstract:Abstract We have addressed the role of serotonin-2C (5-HT 2C ) receptors in the development and maintenance of synaptic plasticity in the Kitten visual cortex. In visual cortical slices, taken from 40- to 80-day-old Kittens, bath application of serotonin markedly facilitated the induction of both long-term depression (LTD) and long-term potentiation (LTP). Field potential responses to white matter stimulation were recorded from layer IV after a regime of low frequency stimulation (LFS; 1 Hz, 15 min), which reliably induced LTP or LTD in younger Kittens (less than 30 days of age). At 40–80 days, this protocol almost never induced LTD or LTP in layer IV. However, in 50% of the visual cortical slices studied in 40–80-day-old Kittens, LTD or LTP was induced, if serotonin (1 or 10 μ M) was co-applied with LFS. No such serotonin facilitation of long-term plasticity was ever detected in >120-day-old animals, indicating that serotonin facilitates synaptic plasticity within a defined period of visual cortical development. Serotonergic 5-HT 2C receptors are likely to contribute to the synaptic plasticity observed in layer IV, since mesulergine, an antagonist of the 5-HT 2C receptor, completely blocked synaptic modifications induced by the combination of low frequency stimulation and serotonin application.
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Blockade of serotonin-2C receptors by mesulergine reduces ocular dominance plasticity in Kitten visual cortex.
Experimental Brain Research, 1997Co-Authors: Yongchang Wang, Qiang Gu, Max S. CynaderAbstract:We have investigated the role of serotonin-2C (5-HT2C) receptors in modulation of ocular dominance plasticity in Kitten visual cortex. A small quantity of the 5-HT2C receptor blocker, mesulergine, was infused into the visual cortex of one hemisphere of 5- to 7-week-old Kittens using osmotic minipumps, while the control hemisphere received vehicle solution. At the same time, one eyelid of the experimental animals was sutured shut. The ocular dominance distributions in the visual cortex (area 17) were assessed using extracellular recording methods after 1 week of combined mesulergine infusion and monocular deprivation. We found that the majority of the neurons remained binocularly responsive in the mesulergine-treated hemisphere, while most of the neurons recorded were either unresponsive or only weakly responsive to the deprived eye in the control hemisphere. Local infusion of mesulergine into the Kitten visual cortex thus reduced the shift of ocular dominance that normally occurs in animals of these ages following monocular deprivation. The blocking effect seems to be distance-dependent and therefore dose-dependent: the farther away the recording sites were from the injection site, the fewer binocularly responsive cells were found. These results are relevant to previous findings indicating transient overexpression of 5-HT2C receptor in visual cortex of Kittens at these ages. The data suggest that the 5-HT2C receptor system may be involved in the formation and modification of ocular dominance columns in the developing visual cortex.
Reidar Andersen - One of the best experts on this subject based on the ideXlab platform.
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risk taking by eurasian lynx lynx lynx in a human dominated landscape effects of sex and reproductive status
Journal of Zoology, 2006Co-Authors: Nils Bunnefeld, John D C Linnell, John Odden, Van Marijtje Duijn, Reidar AndersenAbstract:This study aimed to test how the sex and reproductive status of Eurasian lynx influenced their use of ‘attractive sinks’ – habitats with high prey density and high mortality risks. Locations of 24 Eurasian lynx Lynx lynx were obtained by radiotelemetry in a mixed forest and agricultural habitat in south-eastern Norway. Roe deer, the major food source of lynx in the study area, occurred at higher densities closer to areas of human activity and infrastructure. Proximity of lynx locations to human activity and infrastructure was used as a risk index because the most common causes of death among Scandinavian lynx were of anthropogenic origin. This study shows that distances from lynx locations to human activity were significantly greater for females with newborn Kittens than for males, but this decreased with Kitten age. The data suggest that this response to human activity is influenced by the reproductive strategies of males and females, and might explain male-biased human-induced mortality in this study and in carnivores more generally.
Ljubomir Kojic - One of the best experts on this subject based on the ideXlab platform.
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columnar distribution of serotonin dependent plasticity within Kitten striate cortex
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Ljubomir Kojic, Robert M Douglas, Richard H Dyck, Joanne A Matsubara, Max S. CynaderAbstract:Recent studies have identified the potential for an important role for serotonin (5-HT) receptors in the developmental plasticity of the Kitten visual cortex. 5-HT2C receptors are transiently expressed in a patchy fashion in the visual cortex of Kittens between 30–80 days of age complementary to patches demarcated by cytochrome oxidase staining. 5-HT, operating via 5-HT2C receptors, increases cortical synaptic plasticity as assessed both in brain slices and in vivo. Herein, we report that bath application of 5-HT substantially increases the probability of long-term potentiation within 5-HT2C receptor-rich zones of cortex, but this effect is not observed in the 5-HT2C receptor-poor zones. Instead, in these zones, 5-HT application increases the probability of long-term depression. These location-specific effects of 5-HT may promote the formation of compartment-specific cortical responses.
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serotonin facilitates synaptic plasticity in Kitten visual cortex an in vitro study
Developmental Brain Research, 1997Co-Authors: Ljubomir Kojic, Robert M Douglas, Max S. CynaderAbstract:Abstract We have addressed the role of serotonin-2C (5-HT 2C ) receptors in the development and maintenance of synaptic plasticity in the Kitten visual cortex. In visual cortical slices, taken from 40- to 80-day-old Kittens, bath application of serotonin markedly facilitated the induction of both long-term depression (LTD) and long-term potentiation (LTP). Field potential responses to white matter stimulation were recorded from layer IV after a regime of low frequency stimulation (LFS; 1 Hz, 15 min), which reliably induced LTP or LTD in younger Kittens (less than 30 days of age). At 40–80 days, this protocol almost never induced LTD or LTP in layer IV. However, in 50% of the visual cortical slices studied in 40–80-day-old Kittens, LTD or LTP was induced, if serotonin (1 or 10 μ M) was co-applied with LFS. No such serotonin facilitation of long-term plasticity was ever detected in >120-day-old animals, indicating that serotonin facilitates synaptic plasticity within a defined period of visual cortical development. Serotonergic 5-HT 2C receptors are likely to contribute to the synaptic plasticity observed in layer IV, since mesulergine, an antagonist of the 5-HT 2C receptor, completely blocked synaptic modifications induced by the combination of low frequency stimulation and serotonin application.
Nils Bunnefeld - One of the best experts on this subject based on the ideXlab platform.
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risk taking by eurasian lynx lynx lynx in a human dominated landscape effects of sex and reproductive status
Journal of Zoology, 2006Co-Authors: Nils Bunnefeld, John D C Linnell, John Odden, Van Marijtje Duijn, Reidar AndersenAbstract:This study aimed to test how the sex and reproductive status of Eurasian lynx influenced their use of ‘attractive sinks’ – habitats with high prey density and high mortality risks. Locations of 24 Eurasian lynx Lynx lynx were obtained by radiotelemetry in a mixed forest and agricultural habitat in south-eastern Norway. Roe deer, the major food source of lynx in the study area, occurred at higher densities closer to areas of human activity and infrastructure. Proximity of lynx locations to human activity and infrastructure was used as a risk index because the most common causes of death among Scandinavian lynx were of anthropogenic origin. This study shows that distances from lynx locations to human activity were significantly greater for females with newborn Kittens than for males, but this decreased with Kitten age. The data suggest that this response to human activity is influenced by the reproductive strategies of males and females, and might explain male-biased human-induced mortality in this study and in carnivores more generally.
Miguel Delibes - One of the best experts on this subject based on the ideXlab platform.
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the use of breeding dens and Kitten development in the iberian lynx lynx pardinus
Journal of Zoology, 2002Co-Authors: Nestor Fernandez, Francisco Palomares, Miguel DelibesAbstract:The use of breeding dens and the early Kitten development was studied in a free-ranging population of Iberian lynx Lynx pardinus. Radio-tracking of female lynx allowed intensive monitoring of three litters during 1997, and additional data to be obtained from nine other litters in the previous 4 years. Females gave birth a maximum of one litter per year in spring; nine of the 10 births were recorded between the last 2 weeks of March and the first days of April. Kittens were born semi-altricial and reared for nearly 20 days in secluded hollow trunks. Afterwards, they were moved between different bushes, which served as auxiliary dens, where they began to develop walking and senses. Kittens first consumed meat at the age of 4 weeks, although they were not fully weaned until they were at least 10 weeks old. At the age of 2 months, Kittens began to leave the dens, accompanying their mothers on outings. It is suggested that the pattern of den use was related to the stage of Kitten development, to fulfil the Kittens’ need for both protection and space as they grew. Data on Kitten denning and development should be accounted for in in-situ and ex-situ conservation programmes for this endangered felid.
