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Neonatal EGF challenge permanently alters physiological property of dopaminergic neurons in the ventral tegmental area
Abstracts / Neuroscience Research 68S (2010) e335–e446
P3-q06 Behavioral profiles of three C57BL/6 substrains Keizo Takao 1,2,3,4,5 , Naoki Matsuo 3,4 , Kazuo Nakanishi 2,4,5 , Tanda 2,4,5 , Tsuyoshi Nobuyuki Yamasaki 2,4,5 , Koichi Miyakawa 1,2,3,4,5 1
Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Japan 2 Frontier Technology Center, Graduate School of Medicine Kyoto University, Kyoto, Japan 3 Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan 4 JST, Core Research for Evolutional Science and Technology (CREST), Kawaguchi, Japan 5 JST, Institute for Bioinformatics Research and Development (BIRD), Kawaguchi, Japan C57BL/6 inbred strains of mice are widely used in knockout and transgenic research. To evaluate the loss-of-function and gain-of-function effects of the gene of interest, animal behaviors are often examined. However, an issue of C57BL/6 substrains is not always appreciated though behaviors of mice are known to be strongly influenced by genetic background. To investigate the behavioral characteristics of C57BL/6 substrains, we subjected C57BL/6J, C57BL/6N, and C57BL/6C mice to a behavioral test battery. We performed both a regular-scale analysis whose experimental conditions were tightly controlled and meta-analysis from large number of behavioral data, derived from 700∼2,200 mice in total, that we have collected so far through the comprehensive behavioral test battery. Significant differences were found in various behavioral tests, including the open field, rotarod, elevated plus maze, startle response/prepulse inhibition, Porsolt forced swim, and spatial working memory version of the 8-arm radial maze among the substrains. Our results show divergence of behavioral performance in C57BL/6 substrains and therefore indicate that small genetic differences might have great influence on behavioral phenotypes. Thus, genetic background of different substrains should be carefully chosen, equated, and considered in the interpretation of the mutant behavioral phenotypes. doi:10.1016/j.neures.2010.07.1918
P3-q07 Effects of multiple nerve crushes on functional recovery of the sciatic nerve Toshiro Itsubo 1 , Akira Kakegawa 2 , Kumiko Yokouchi 2 , Kyutaro Kawagishi 2 , Tetsuji Moriizumi 2 , Nanae Fukushima 2 1
Department of Orthopaedic Surgery, Shinshu University School of Medicine Department of Anatomy, Shinshu University School of Medicine, Matsumoto, Japan 2
Motor neurons can survive and reinnervate the muscles after the sciatic nerve crush injury. In this study, we investigated the effects of multiple nerve crush injuries on functional recovery and reinnervation of muscles. Using functional and immunohistochemical analyses, we evaluated the effects of nerve crush injuries. Motor function was estimated by the sciatic static index (SSI), measuring two parameters of 1-5 toe spread and 2–4 toe spread lengths on both sides, and the SSI scores became a normal range in 4 weeks after the single sciatic nerve crush injury. However, the SSI scores in the rats with the triple nerve crush injuries every week did not recover to normal range up to 8 weeks. Comparisons between the single and triple crush injuries every week were made with muscle fiber diameter and reinnervation of the tibialis anterior muscles. In the rats with the triple nerve crush injuries, the average diameters of 50 muscle fibers were significantly smaller than those with the single nerve crush injury at the point of 2, 3 and 4 weeks after the last crush injury. Reinnervation of the muscles was estimated by the ratio of synaptophysin positive nerve terminals in presynaptic membrane for ␣-bungarotoxin positive neuroreceptors in postsynaptic membrane. At the point of 3 weeks after the last crush injury, the amount of reinnervation of the muscles in the rats with the triple nerve crush injuries was lower than that with the single nerve crush injury. In the rats with repeated sciatic nerve crush injuries at short intervals before recovering motor function, the function may not recover completely because of delay of the reinnervation and the atrophy of the muscles. doi:10.1016/j.neures.2010.07.1919
e433
P3-q08 Neonatal EGF challenge permanently alters physiological property of dopaminergic neurons in the ventral tegmental area Hisaaki Namba , Hiroyuki Nawa Department of Mol. Neurobiol., Brain Res. Inst., Niigata University The neurotophic agent, epidermal growth factor (EGF) is implicated in dopamine-associated brain diseases. We found that neonatal exposure to EGF transiently enhances synaptic and neurochemical development of midbrain dopaminergic neurons, although we do not know how this postnatal EGF action influences later physiological property of this neuronal population. We prepared midbrain slice preparations from adult mice treated with EGF as neonates, and analyzed spontaneous firing activity of dopaminergic neurons and their sensitivity to a dopamine D2 receptor agonist. Cell-attached recording reveals that neonatal EGF treatment decreased the frequency of their pacemaker firing in the ventral tegmental area but not in the substantia nigra compacta. Subsequent whole-cell analysis indicates that EGF increased the threshold of membrane potential generating spikes. D2R agonist application to dopaminergic neurons attenuated their firing frequency in a dose dependent manner, but the magnitude of the suppression was not affected by EGF treatment. Thus, neurotrophic over-stimulation might perturb the physiological development of dopaminergic neurons and contribute to their pathophysiology of psychiatric diseases. doi:10.1016/j.neures.2010.07.1920
P3-q09 Gamma knife irradiation operates differentially on the neuronal subpopulations of the rat basal ganglia Nobuo Kouyama 1 , Yoko Katayama 1 , Motohiro Hayashi 2 , Yoriko Kawakami 1 1
Department Physiol, Tokyo Women’s Med Univ, Tokyo 2 Department Neurosurgery, Tokyo Women’s Med University, Tokyo To investigate the effect of gamma knife irradiation to the neuronal tissues, we have surveyed the histological disruption derived by the unilateral irradiation to the rat brain. Irradiation of high dose gamma ray provoked the necrosis of the brain tissues at the target area, and the rotation behaviors after prolonged survival. In this study, the effect of relatively weak, subnecrotic dose of irradiation and/or shorter survival period will be reported. After the irradiation, the nuclei of the basal ganglia between the striatum and the substantia nigra were systematically surveyed with immunohistochemistry. There was no necrotic lesion with this condition in macroscopic level. As we have reported previously, glial cells are susceptible to the irradiation. A low dose irradiation made the astrocytes to be swollen, giant cells in the target area. Microglia were found in activated form. The fate of the neurons depended on their subtypes. No obvious alteration of the immunoreactivity (IR) to calretinin (CR), tyrosine hydroxylase (TH), mu-opioid receptor (MOPR) was noticed. On the contrary, the IR to enkephalin (Enk) and calbindin (CB) were clearly enhanced over the irradiated hemisphere. They lost, however, the certain localization to the specific neuron subtypes and cytological structures, such as somata. The IR became diffused in the tissues, probably to the extracellular spaces, leaving the neuronal somata unlabeled like the negative stain. The patch/matrix segregation, which could be observed by the CB-IR in the unirradiated striatum, became unclear. Interestingly, however, it could be seen in the next sections by MOPR-IR. There are parvalbumin (PV)-IR neurons over the basal ganglia. The PV labeling of somata in the irradiated lateral globus pallidus, and of the fibers were reduced. These results indicate subtype specific operations of gamma knife in the nervous tissue. doi:10.1016/j.neures.2010.07.1921
P3-q10 Facilitating brain-machine interface research through data-sharing Satoshi Murata , Makoto Takemiya, Yukiyasu Kamitani ATR CNS Brain–machine interface (BMI) research combines algorithms and techniques from computer science with the emphasis on empirical physiological data analysis from neuroscience. On of the goals of BMI is to be able to decode brain signals so that a computer can “read” a person’s cognitive state in order to perform a task. BMI research is inhibited by the fact that collecting data to test new algorithms is time-consuming and costly. Furthermore, people with a solid background in algorithms and theoretical computer science may not have the skills or necessary resources to carry out neurophysiological exper-
P3-q06 Behavioral profiles of three C57BL/6 substrains Keizo Takao 1,2,3,4,5 , Naoki Matsuo 3,4 , Kazuo Nakanishi 2,4,5 , Tanda 2,4,5 , Tsuyoshi Nobuyuki Yamasaki 2,4,5 , Koichi Miyakawa 1,2,3,4,5 1
Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Japan 2 Frontier Technology Center, Graduate School of Medicine Kyoto University, Kyoto, Japan 3 Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan 4 JST, Core Research for Evolutional Science and Technology (CREST), Kawaguchi, Japan 5 JST, Institute for Bioinformatics Research and Development (BIRD), Kawaguchi, Japan C57BL/6 inbred strains of mice are widely used in knockout and transgenic research. To evaluate the loss-of-function and gain-of-function effects of the gene of interest, animal behaviors are often examined. However, an issue of C57BL/6 substrains is not always appreciated though behaviors of mice are known to be strongly influenced by genetic background. To investigate the behavioral characteristics of C57BL/6 substrains, we subjected C57BL/6J, C57BL/6N, and C57BL/6C mice to a behavioral test battery. We performed both a regular-scale analysis whose experimental conditions were tightly controlled and meta-analysis from large number of behavioral data, derived from 700∼2,200 mice in total, that we have collected so far through the comprehensive behavioral test battery. Significant differences were found in various behavioral tests, including the open field, rotarod, elevated plus maze, startle response/prepulse inhibition, Porsolt forced swim, and spatial working memory version of the 8-arm radial maze among the substrains. Our results show divergence of behavioral performance in C57BL/6 substrains and therefore indicate that small genetic differences might have great influence on behavioral phenotypes. Thus, genetic background of different substrains should be carefully chosen, equated, and considered in the interpretation of the mutant behavioral phenotypes. doi:10.1016/j.neures.2010.07.1918
P3-q07 Effects of multiple nerve crushes on functional recovery of the sciatic nerve Toshiro Itsubo 1 , Akira Kakegawa 2 , Kumiko Yokouchi 2 , Kyutaro Kawagishi 2 , Tetsuji Moriizumi 2 , Nanae Fukushima 2 1
Department of Orthopaedic Surgery, Shinshu University School of Medicine Department of Anatomy, Shinshu University School of Medicine, Matsumoto, Japan 2
Motor neurons can survive and reinnervate the muscles after the sciatic nerve crush injury. In this study, we investigated the effects of multiple nerve crush injuries on functional recovery and reinnervation of muscles. Using functional and immunohistochemical analyses, we evaluated the effects of nerve crush injuries. Motor function was estimated by the sciatic static index (SSI), measuring two parameters of 1-5 toe spread and 2–4 toe spread lengths on both sides, and the SSI scores became a normal range in 4 weeks after the single sciatic nerve crush injury. However, the SSI scores in the rats with the triple nerve crush injuries every week did not recover to normal range up to 8 weeks. Comparisons between the single and triple crush injuries every week were made with muscle fiber diameter and reinnervation of the tibialis anterior muscles. In the rats with the triple nerve crush injuries, the average diameters of 50 muscle fibers were significantly smaller than those with the single nerve crush injury at the point of 2, 3 and 4 weeks after the last crush injury. Reinnervation of the muscles was estimated by the ratio of synaptophysin positive nerve terminals in presynaptic membrane for ␣-bungarotoxin positive neuroreceptors in postsynaptic membrane. At the point of 3 weeks after the last crush injury, the amount of reinnervation of the muscles in the rats with the triple nerve crush injuries was lower than that with the single nerve crush injury. In the rats with repeated sciatic nerve crush injuries at short intervals before recovering motor function, the function may not recover completely because of delay of the reinnervation and the atrophy of the muscles. doi:10.1016/j.neures.2010.07.1919
e433
P3-q08 Neonatal EGF challenge permanently alters physiological property of dopaminergic neurons in the ventral tegmental area Hisaaki Namba , Hiroyuki Nawa Department of Mol. Neurobiol., Brain Res. Inst., Niigata University The neurotophic agent, epidermal growth factor (EGF) is implicated in dopamine-associated brain diseases. We found that neonatal exposure to EGF transiently enhances synaptic and neurochemical development of midbrain dopaminergic neurons, although we do not know how this postnatal EGF action influences later physiological property of this neuronal population. We prepared midbrain slice preparations from adult mice treated with EGF as neonates, and analyzed spontaneous firing activity of dopaminergic neurons and their sensitivity to a dopamine D2 receptor agonist. Cell-attached recording reveals that neonatal EGF treatment decreased the frequency of their pacemaker firing in the ventral tegmental area but not in the substantia nigra compacta. Subsequent whole-cell analysis indicates that EGF increased the threshold of membrane potential generating spikes. D2R agonist application to dopaminergic neurons attenuated their firing frequency in a dose dependent manner, but the magnitude of the suppression was not affected by EGF treatment. Thus, neurotrophic over-stimulation might perturb the physiological development of dopaminergic neurons and contribute to their pathophysiology of psychiatric diseases. doi:10.1016/j.neures.2010.07.1920
P3-q09 Gamma knife irradiation operates differentially on the neuronal subpopulations of the rat basal ganglia Nobuo Kouyama 1 , Yoko Katayama 1 , Motohiro Hayashi 2 , Yoriko Kawakami 1 1
Department Physiol, Tokyo Women’s Med Univ, Tokyo 2 Department Neurosurgery, Tokyo Women’s Med University, Tokyo To investigate the effect of gamma knife irradiation to the neuronal tissues, we have surveyed the histological disruption derived by the unilateral irradiation to the rat brain. Irradiation of high dose gamma ray provoked the necrosis of the brain tissues at the target area, and the rotation behaviors after prolonged survival. In this study, the effect of relatively weak, subnecrotic dose of irradiation and/or shorter survival period will be reported. After the irradiation, the nuclei of the basal ganglia between the striatum and the substantia nigra were systematically surveyed with immunohistochemistry. There was no necrotic lesion with this condition in macroscopic level. As we have reported previously, glial cells are susceptible to the irradiation. A low dose irradiation made the astrocytes to be swollen, giant cells in the target area. Microglia were found in activated form. The fate of the neurons depended on their subtypes. No obvious alteration of the immunoreactivity (IR) to calretinin (CR), tyrosine hydroxylase (TH), mu-opioid receptor (MOPR) was noticed. On the contrary, the IR to enkephalin (Enk) and calbindin (CB) were clearly enhanced over the irradiated hemisphere. They lost, however, the certain localization to the specific neuron subtypes and cytological structures, such as somata. The IR became diffused in the tissues, probably to the extracellular spaces, leaving the neuronal somata unlabeled like the negative stain. The patch/matrix segregation, which could be observed by the CB-IR in the unirradiated striatum, became unclear. Interestingly, however, it could be seen in the next sections by MOPR-IR. There are parvalbumin (PV)-IR neurons over the basal ganglia. The PV labeling of somata in the irradiated lateral globus pallidus, and of the fibers were reduced. These results indicate subtype specific operations of gamma knife in the nervous tissue. doi:10.1016/j.neures.2010.07.1921
P3-q10 Facilitating brain-machine interface research through data-sharing Satoshi Murata , Makoto Takemiya, Yukiyasu Kamitani ATR CNS Brain–machine interface (BMI) research combines algorithms and techniques from computer science with the emphasis on empirical physiological data analysis from neuroscience. On of the goals of BMI is to be able to decode brain signals so that a computer can “read” a person’s cognitive state in order to perform a task. BMI research is inhibited by the fact that collecting data to test new algorithms is time-consuming and costly. Furthermore, people with a solid background in algorithms and theoretical computer science may not have the skills or necessary resources to carry out neurophysiological exper-