The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Janice M. Juraska - One of the best experts on this subject based on the ideXlab platform.
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hippocampal anatomy and water maze performance are affected by neonatal Cryoanesthesia in rats of both sexes
Hormones and Behavior, 2000Co-Authors: Joseph L Nunez, Wendy A Koss, Janice M. JuraskaAbstract:There is recent evidence that Cryoanesthesia, commonly used during neonatal hormone manipulations (e.g., gonadectomy), has deleterious effects on the morphology of the splenium of the corpus callosum and primary visual cortex in adult rats of both sexes. (Nunez and Juraska, 1998; Nunez, Kim, and Juraska, 1998). In the present study, the effect of neonatal Cryoanesthesia on the morphology of the hippocampus and dentate gyrus and on performance in the Morris water maze was investigated. Cold exposure for as brief as 30 min (5 degrees C) on Postnatal Day 1 resulted in a significant decrease in the volume of the hippocampus and in brain weight of adults. Performance on the water maze was also impaired in cold-exposed animals. This study indicates that not only morphology but also behavioral performance in adulthood are affected by neonatal Cryoanesthesia.
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the size of the splenium of the rat corpus callosum influence of hormones sex ratio and neonatal Cryoanesthesia
Developmental Psychobiology, 1998Co-Authors: Joseph L Nunez, Janice M. JuraskaAbstract:The splenium (posterior of the corpus callosum is sexually dimorphic in the 1⁄ 5) adult rat brain. In the present study we examined the role of developmental hormones and Cryoanesthesia (which is normally used during the performance of neonatal hormone manip- ulations) on the gross size of the splenium in male and female rats. There was a sex difference in splenial size (male. female) among nonhormonally manipulated animals, p 5 .0007. While neonatal castration was ineffective in altering the size of the male splenium, testosterone in- jections in females were found to increase the size of the splenium relative to oil-injected females, p 5 .05. The effect of developmental testosterone was further observed: Sex ratio (males to females) of the litter correlated with splenial area in females, r5 .55, p 5 .03. Duration of Cryoanesthesia negatively correlated with splenial area in males, r .81, p 5 .03, with a similar trend in females. q 1998 John Wiley & Sons, Inc.Dev Psychobiol 33: 295- 303, 1998
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neonatal Cryoanesthesia affects the morphology of the visual cortex in the adult rat
Developmental Brain Research, 1998Co-Authors: Joseph L Nunez, Bennet Y Kim, Janice M. JuraskaAbstract:Abstract Hypothermia is often employed as an anesthetic for manipulations of neonatal animals. We previously reported [J. Nunez, J.M. Juraska, The effect of neonatal Cryoanesthesia on the gross size of the splenium of the corpus callosum, Dev. Psychobiol. 30 (1997) 259; J. Nunez, J.M. Juraska, The size of the splenium of the rat corpus callosum: influence of hormones, sex ratio and neonatal Cryoanesthesia, Dev. Psychobiol., in press.] that the area of the splenium of the adult rat corpus callosum negatively correlated with the time neonatal pups spent in the cold. In the present study, we examined the effect of exposure to neonatal hypothermia (0, 15, 30 and 60 min at 4°C, within 2 h of birth) on the thickness and volume of the binocular (Oc1B) and monocular (Oc1M) fields of the adult rat visual cortex. The number of neurons and glia in layer 2/3 in these areas was also assessed in the 0 and 60 min cold-exposed groups. Cryoanesthesia significantly decreased the length, thickness, volume and number of neurons and glia in both Oc1M and Oc1B. We also observed significant effects of cold exposure on the thickness of individual cortical layers, with some layers affected more than others after differential exposure times. Sex differences (males greater than females) were observed in a number of measures after varying amounts of time in cold and in the absence of cold exposure, in confirmation of previous work from our lab [S.N.M. Reid, J.M. Juraska, Sex differences in the gross size of the rat neocortex, J. Comp. Neurol. 321 (1992) 442–447; S.N.M. Reid, J.M. Juraska, Sex differences in neuron number in the binocular area of the rat visual cortex, J. Comp. Neurol. 321 (1992) 448–455.]. The present study points to the potential confound of using Cryoanesthesia on neonatal animals to study cortical structure or function.
Joseph L Nunez - One of the best experts on this subject based on the ideXlab platform.
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hippocampal anatomy and water maze performance are affected by neonatal Cryoanesthesia in rats of both sexes
Hormones and Behavior, 2000Co-Authors: Joseph L Nunez, Wendy A Koss, Janice M. JuraskaAbstract:There is recent evidence that Cryoanesthesia, commonly used during neonatal hormone manipulations (e.g., gonadectomy), has deleterious effects on the morphology of the splenium of the corpus callosum and primary visual cortex in adult rats of both sexes. (Nunez and Juraska, 1998; Nunez, Kim, and Juraska, 1998). In the present study, the effect of neonatal Cryoanesthesia on the morphology of the hippocampus and dentate gyrus and on performance in the Morris water maze was investigated. Cold exposure for as brief as 30 min (5 degrees C) on Postnatal Day 1 resulted in a significant decrease in the volume of the hippocampus and in brain weight of adults. Performance on the water maze was also impaired in cold-exposed animals. This study indicates that not only morphology but also behavioral performance in adulthood are affected by neonatal Cryoanesthesia.
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the size of the splenium of the rat corpus callosum influence of hormones sex ratio and neonatal Cryoanesthesia
Developmental Psychobiology, 1998Co-Authors: Joseph L Nunez, Janice M. JuraskaAbstract:The splenium (posterior of the corpus callosum is sexually dimorphic in the 1⁄ 5) adult rat brain. In the present study we examined the role of developmental hormones and Cryoanesthesia (which is normally used during the performance of neonatal hormone manip- ulations) on the gross size of the splenium in male and female rats. There was a sex difference in splenial size (male. female) among nonhormonally manipulated animals, p 5 .0007. While neonatal castration was ineffective in altering the size of the male splenium, testosterone in- jections in females were found to increase the size of the splenium relative to oil-injected females, p 5 .05. The effect of developmental testosterone was further observed: Sex ratio (males to females) of the litter correlated with splenial area in females, r5 .55, p 5 .03. Duration of Cryoanesthesia negatively correlated with splenial area in males, r .81, p 5 .03, with a similar trend in females. q 1998 John Wiley & Sons, Inc.Dev Psychobiol 33: 295- 303, 1998
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neonatal Cryoanesthesia affects the morphology of the visual cortex in the adult rat
Developmental Brain Research, 1998Co-Authors: Joseph L Nunez, Bennet Y Kim, Janice M. JuraskaAbstract:Abstract Hypothermia is often employed as an anesthetic for manipulations of neonatal animals. We previously reported [J. Nunez, J.M. Juraska, The effect of neonatal Cryoanesthesia on the gross size of the splenium of the corpus callosum, Dev. Psychobiol. 30 (1997) 259; J. Nunez, J.M. Juraska, The size of the splenium of the rat corpus callosum: influence of hormones, sex ratio and neonatal Cryoanesthesia, Dev. Psychobiol., in press.] that the area of the splenium of the adult rat corpus callosum negatively correlated with the time neonatal pups spent in the cold. In the present study, we examined the effect of exposure to neonatal hypothermia (0, 15, 30 and 60 min at 4°C, within 2 h of birth) on the thickness and volume of the binocular (Oc1B) and monocular (Oc1M) fields of the adult rat visual cortex. The number of neurons and glia in layer 2/3 in these areas was also assessed in the 0 and 60 min cold-exposed groups. Cryoanesthesia significantly decreased the length, thickness, volume and number of neurons and glia in both Oc1M and Oc1B. We also observed significant effects of cold exposure on the thickness of individual cortical layers, with some layers affected more than others after differential exposure times. Sex differences (males greater than females) were observed in a number of measures after varying amounts of time in cold and in the absence of cold exposure, in confirmation of previous work from our lab [S.N.M. Reid, J.M. Juraska, Sex differences in the gross size of the rat neocortex, J. Comp. Neurol. 321 (1992) 442–447; S.N.M. Reid, J.M. Juraska, Sex differences in neuron number in the binocular area of the rat visual cortex, J. Comp. Neurol. 321 (1992) 448–455.]. The present study points to the potential confound of using Cryoanesthesia on neonatal animals to study cortical structure or function.
J M Pequignot - One of the best experts on this subject based on the ideXlab platform.
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long term effects of neonatal Cryoanesthesia on hypoxic ventilatory response in weanling rats depend on neonatal testosterone
Advances in Experimental Medicine and Biology, 2003Co-Authors: Joseph Vincent, Jorge Soliz, J M PequignotAbstract:Among the factors known to interact with the developmental plasticity of the respiratory controller network, gender and perinatal testosterone secretion have recently been described to influence the ventilatory response to acute or chronic hypoxia before puberty (Mortola et al 1996; Joseph et al 1999; Joseph et al 2000). In the present experiments, we used Cryoanesthesia as a tool to perform neonatal gonadectomy to address the hypothesis that endogenous neonatal testosterone secretion in male pups could affect the hypoxic ventilatory response (HVR - 10 % O2) in weanling (20-22 day-old) male rats. We selected weaning as an age of fully mature HVR (Joseph et al 2000), while rats are still sexually immature, thus allowing to discard any effect related to endogenous secretion of adult testes (Tatsumi et al. 1994). Our findings show that Cryoanesthesia by itself produces a marked decrease of HVR in weanling rats, and this effect was dependent on the neonatal testosterone secretion. Because the Cryoanesthesia approach is in many ways similar to surgical processes used for arterial switch operation in human neonates (performed under cardiopulmonary bypass, cardiocirculatory arrest and deep hypothermia), our findings may be potentially relevant for long term outcomes of infants submitted to this surgical procedure.
Todd E Golde - One of the best experts on this subject based on the ideXlab platform.
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the effect of brief neonatal Cryoanesthesia on physical development and adult cognitive function in mice
Behavioural Brain Research, 2014Co-Authors: Christopher Janus, Todd E GoldeAbstract:Abstract Deep hypothermia (Cryoanesthesia) is often used as general anesthesia during surgery in neonatal rodents. Neonatal Cryoanesthesia has been used recently to generate somatic brain transgenic (SBT) mouse models via intracerebral ventricular injection of rAAV vectors into both non-transgenic mice and numerous transgenic mouse models. Since, the evaluation of cognition is one of the main experimental endpoints in many of these studies, we examined the consequences of brief neonatal Cryoanesthesia on the physical development and mnemonic function of adult mice. Two groups of 129FVBF1 pups from reciprocal breeding crosses underwent Cryoanesthesia for 6 min (Cryo6) or 12 min (Cryo12), respectively, within the first hours (
Joseph Vincent - One of the best experts on this subject based on the ideXlab platform.
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long term effects of neonatal Cryoanesthesia on hypoxic ventilatory response in weanling rats depend on neonatal testosterone
Advances in Experimental Medicine and Biology, 2003Co-Authors: Joseph Vincent, Jorge Soliz, J M PequignotAbstract:Among the factors known to interact with the developmental plasticity of the respiratory controller network, gender and perinatal testosterone secretion have recently been described to influence the ventilatory response to acute or chronic hypoxia before puberty (Mortola et al 1996; Joseph et al 1999; Joseph et al 2000). In the present experiments, we used Cryoanesthesia as a tool to perform neonatal gonadectomy to address the hypothesis that endogenous neonatal testosterone secretion in male pups could affect the hypoxic ventilatory response (HVR - 10 % O2) in weanling (20-22 day-old) male rats. We selected weaning as an age of fully mature HVR (Joseph et al 2000), while rats are still sexually immature, thus allowing to discard any effect related to endogenous secretion of adult testes (Tatsumi et al. 1994). Our findings show that Cryoanesthesia by itself produces a marked decrease of HVR in weanling rats, and this effect was dependent on the neonatal testosterone secretion. Because the Cryoanesthesia approach is in many ways similar to surgical processes used for arterial switch operation in human neonates (performed under cardiopulmonary bypass, cardiocirculatory arrest and deep hypothermia), our findings may be potentially relevant for long term outcomes of infants submitted to this surgical procedure.