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The neural circuit formation of the turtle trunk region
Abstracts Acknowledgements Grant: supported by the JSPS KAKENHI (20590176). Ethics: approved by the Institutional Animal Care and Use Committee of Shin Nippon Biomedical Laboratories. doi:10.1016/j.neures.2009.09.774
P2-d03 The neural circuit formation of the turtle trunk region Masahumi Kawaguchi 1,2 , Aki Watanabe 2 , Hiroshi Nagashima 3 , Shigeru kuratani 3 , Yasunori Murakami 2 1
CMES, Ehime University, Japan; 2 Biology Fac. of Sci., Ehime University, Japan; 3 Lab. for Evolutionary Morphology, RIKEN CDB, Japan
The turtle has the shell, which is derived from ribs. In general vertebrate, the rib primordiums project from dorsal side to ventral, whereas they project horizontally at dorsal side in turtle. Such a peculiar modification of the body plan appears to change the peripheral nerve patterning at dorsal side of the turtle trunk region. However, it is unknown how the specific nerve system develops during turtle embryonic stage. To explore it, we analyzed the wiring structure of trunk nerve system and the expression pattern of the genes related to neural circuit formation in Pelodiscus Sinensis. Immunohistochemistry showed that the turtle embryo at stage 14 contained dorsal branches of spinal nerves. By in situ hybridization, Lhx3, a marker for the motoneurons projecting to the dorsal branches, was expressed in the turtle spinal cord at stage 12. We then analyzed expression pattern of axon guidance molecules (Sema3a, EphA4 and Fgf8) to clarify the mechanism for modification of the turtle specific trunk nerve system. doi:10.1016/j.neures.2009.09.775
P2-d04 Gene expression pattern and its alteration in the developing Dreher mutant inner ear Katsuhiko Ono 1,2 , Miki Furusho 2 , Hitoshi Gotoh 2 , Hirohide Takebayashi 2,3 , Kazuhiro Ikenaka 2 1
Dept Biol, Kyoto Pref Univ Med, Kyoto, Japan; 2 Div Neurobiol Bioinfo, Natl Inst Physiol Sci, Okazaki, Japan; 3 Dept Morph Neural Sci, Kumamoto Univ, Kumamoto, Japan Dreher mutant mouse carries mutated Lmx1a gene, resulting in multiple malformations, including nervous system and inner ear. To understand mechanisms underlying inner ear malformation, we examined morphology and gene expression pattern of the mutant inner ear. The inner ear of the E18.5 Dreher mouse is roughly divided into dorsal and ventral portions, though semicircular canals, cochlear or endolymphatic sac was not recognized. In the E10.5 inner ear, genes that demarcate the dorsal and ventral parts of the otocyst seemed to be expressed normally in the mutant mouse, and thus the dorsoventral axis is normally formed in the mutant inner ear. At E12.5, Msx1 was expressed in the distal tip of the cochlear primordium in the wild type animals. However, it was expressed slightly wider in the age-matched mutant cochlear anlage. These results suggest that at least cochlear malformation is involved with altered expression of Msx1 in the Dreher mouse. doi:10.1016/j.neures.2009.09.776
P2-d05 Behavior of avian pallial GABAergic interneurons in the mammalian neocortex: Implications for the evolutional adaptation to the neocortex in pallial GABAergic interneurons Daisuke H. Tanaka, Kazunori Nakajima Keio University School of Medicine, Japan Changes in neuronal migration processes during development might have driven the marked changes of the pallial structures in amniotes during evolution. In most amniotes, pallial GABAergic interneurons are generated in the medial ganglionic eminence (MGE) and migrate tangentially into the pallium. How these MGE-derived GABAergic interneurons, however, have adapted to the marked changes in the pallium during evolution remains unclear. Here, chick MGE cells were labeled with mCherry and grafted with GFP-expressing mouse MGE cells into the mouse MGE in utero, and their distributions were examined at later stages. Although most chick cells behaved like mouse cells in terms of migration and differentiation, we found some specific differences between chick and mouse cells. These data support the idea that overall mechanisms in migration and differentiation are highly conserved between mammals and aves but some specific differences we found might be crucial for MGE-derived GABAergic interneurons to adapt to mammalian neocortex. doi:10.1016/j.neures.2009.09.777
S153
P2-d06 Resveratrol is harmful to naive PC12 cells but beneficial to the differentiated ones Shoichi Takeuchi 1 , Motoko Shiozaki 1 , Naoya Hayakawa 1 , Masahiro Shibata 2 , Masato Koike 3 , Yasuo Uchiyama 3 , Takahiro Gotow 1 1
Lab Cell Biol, Koshien Univ, Takarazuka, Japan; 2 Div Gross Anat Morphogen, Niigata Univ Grad Med Dent, Niigata, Japan; 3 Dept Cell Biol Neurosci, Juntendo Univ, Sch Med, Tokyo, Japan Resveratrol, a polyphenol rich in red wine, is considered to have neuroprotective functions. We analyzed PC12 cells how they are influenced by resveratrol by morphological and biochemical techniques. PC12 cells were cultured in DMEM with10% FBS and changed to the medium with 0.2% FBS. Undifferentiated (naive) PC12 cells were then treated with different concentrations of resveratrol (1, 10 and 100 M) or red wine extracts (0.01, 0.1 and 1%). PC12 cells, differentiated by NGF, were treated in the same way as naive cells. Wine extracts induced neurite extensions of both naive and differentiated PC12 cells but more significantly in the latter. Resveratorol enhanced more powerfully neurite extension of differentiated PC12 cells but inhibited those of naive ones that died in its higher concentration. Resveratrol may kill tumorigenic cells but be beneficial to differentiated ones. doi:10.1016/j.neures.2009.09.778
P2-d07 Genetic trace of mouse neocortical arealization Takayoshi Inoue 1 , Youhei Terakawa 1,2 , Junko Asami 1 , Yukiko U. Inoue 1 1
National Institute of Neuroscience, NCNP, Kodaira, Japan; and Eng, Waseda Univ, Tokyo, Japan
2
Faculty of Sci
The cerebral cortex (neocortex) defined by its characteristic cytoarchitecture can be subdivided into scores of functional areas, yet how these areal organizations emerge during development and/or evolution remains elusive. Here we sought to identify ontogenetic and/or phylogenetic origin of cellular and molecular basis that facilitates neocortical arealization by using an efficient bacterial artificial chromosome (BAC) modification methodology and transgenic evaluation system in mice. Consequently, we obtained variety of BAC transgenic mouse lines in which distinct sets of developing mouse neocortical areas/layers are differentially demarcated via reporter (e.g. LacZ, EGFP, mCherry, etc.) or effector (e.g. CreERT2) gene expressions. This primarily provides evidence that separable genetic program might determine each neocortical area/layer specificity. Those animal resources should further offer new and rigid analytical frameworks in elucidating mechanism of neocortical arealization. doi:10.1016/j.neures.2009.09.779
P2-d08 Mechanism of subunit switching from NR2B to NR2C in mouse cerebellar granule cell cultures Kouichirou Iijima 1 , Haruka Abe 1,2 , Makoto Okazawa 1 , Koki Moriyoshi 3 , Shigetada Nakanishi 1 1
Systems Bio., OBI, Osaka, Japan; 2 Functional Bio., Univ of Kyoto, Kyoto, Japan; 3 Neurosci., Univ of Kyoto, Kyoto, Japan
In the cerebellar development, granule cells switch subunit composition of NMDA receptors from NR2B to NR2C, parallel to synapse formation. This switching alters properties of glutamatergic transmission, and is a key for cerebellar network maturation. We investigated mechanisms of this switching in primary cultures of mouse granule cells at the physiological KCl concentration (5 mM). Granule cells downregulated NR2B mRNA and up-regulated NR2C mRNA, parallel to extensions of neuritic processes. This dual regulation depended on neural activities sensitive to TTX, NBQX, and CPP. Suppression of dual regulation by TTX was restored by selective NMDA stimulation, but not by AMPA stimulation. Importantly, the NMDA stimulation drove switching on NMDA receptors in the cell-surface membrane. The activation of NMDA receptors thus plays a key role in functional subunit switching of NMDA receptors in maturing processes of granule cells. doi:10.1016/j.neures.2009.09.780
P2-d03 The neural circuit formation of the turtle trunk region Masahumi Kawaguchi 1,2 , Aki Watanabe 2 , Hiroshi Nagashima 3 , Shigeru kuratani 3 , Yasunori Murakami 2 1
CMES, Ehime University, Japan; 2 Biology Fac. of Sci., Ehime University, Japan; 3 Lab. for Evolutionary Morphology, RIKEN CDB, Japan
The turtle has the shell, which is derived from ribs. In general vertebrate, the rib primordiums project from dorsal side to ventral, whereas they project horizontally at dorsal side in turtle. Such a peculiar modification of the body plan appears to change the peripheral nerve patterning at dorsal side of the turtle trunk region. However, it is unknown how the specific nerve system develops during turtle embryonic stage. To explore it, we analyzed the wiring structure of trunk nerve system and the expression pattern of the genes related to neural circuit formation in Pelodiscus Sinensis. Immunohistochemistry showed that the turtle embryo at stage 14 contained dorsal branches of spinal nerves. By in situ hybridization, Lhx3, a marker for the motoneurons projecting to the dorsal branches, was expressed in the turtle spinal cord at stage 12. We then analyzed expression pattern of axon guidance molecules (Sema3a, EphA4 and Fgf8) to clarify the mechanism for modification of the turtle specific trunk nerve system. doi:10.1016/j.neures.2009.09.775
P2-d04 Gene expression pattern and its alteration in the developing Dreher mutant inner ear Katsuhiko Ono 1,2 , Miki Furusho 2 , Hitoshi Gotoh 2 , Hirohide Takebayashi 2,3 , Kazuhiro Ikenaka 2 1
Dept Biol, Kyoto Pref Univ Med, Kyoto, Japan; 2 Div Neurobiol Bioinfo, Natl Inst Physiol Sci, Okazaki, Japan; 3 Dept Morph Neural Sci, Kumamoto Univ, Kumamoto, Japan Dreher mutant mouse carries mutated Lmx1a gene, resulting in multiple malformations, including nervous system and inner ear. To understand mechanisms underlying inner ear malformation, we examined morphology and gene expression pattern of the mutant inner ear. The inner ear of the E18.5 Dreher mouse is roughly divided into dorsal and ventral portions, though semicircular canals, cochlear or endolymphatic sac was not recognized. In the E10.5 inner ear, genes that demarcate the dorsal and ventral parts of the otocyst seemed to be expressed normally in the mutant mouse, and thus the dorsoventral axis is normally formed in the mutant inner ear. At E12.5, Msx1 was expressed in the distal tip of the cochlear primordium in the wild type animals. However, it was expressed slightly wider in the age-matched mutant cochlear anlage. These results suggest that at least cochlear malformation is involved with altered expression of Msx1 in the Dreher mouse. doi:10.1016/j.neures.2009.09.776
P2-d05 Behavior of avian pallial GABAergic interneurons in the mammalian neocortex: Implications for the evolutional adaptation to the neocortex in pallial GABAergic interneurons Daisuke H. Tanaka, Kazunori Nakajima Keio University School of Medicine, Japan Changes in neuronal migration processes during development might have driven the marked changes of the pallial structures in amniotes during evolution. In most amniotes, pallial GABAergic interneurons are generated in the medial ganglionic eminence (MGE) and migrate tangentially into the pallium. How these MGE-derived GABAergic interneurons, however, have adapted to the marked changes in the pallium during evolution remains unclear. Here, chick MGE cells were labeled with mCherry and grafted with GFP-expressing mouse MGE cells into the mouse MGE in utero, and their distributions were examined at later stages. Although most chick cells behaved like mouse cells in terms of migration and differentiation, we found some specific differences between chick and mouse cells. These data support the idea that overall mechanisms in migration and differentiation are highly conserved between mammals and aves but some specific differences we found might be crucial for MGE-derived GABAergic interneurons to adapt to mammalian neocortex. doi:10.1016/j.neures.2009.09.777
S153
P2-d06 Resveratrol is harmful to naive PC12 cells but beneficial to the differentiated ones Shoichi Takeuchi 1 , Motoko Shiozaki 1 , Naoya Hayakawa 1 , Masahiro Shibata 2 , Masato Koike 3 , Yasuo Uchiyama 3 , Takahiro Gotow 1 1
Lab Cell Biol, Koshien Univ, Takarazuka, Japan; 2 Div Gross Anat Morphogen, Niigata Univ Grad Med Dent, Niigata, Japan; 3 Dept Cell Biol Neurosci, Juntendo Univ, Sch Med, Tokyo, Japan Resveratrol, a polyphenol rich in red wine, is considered to have neuroprotective functions. We analyzed PC12 cells how they are influenced by resveratrol by morphological and biochemical techniques. PC12 cells were cultured in DMEM with10% FBS and changed to the medium with 0.2% FBS. Undifferentiated (naive) PC12 cells were then treated with different concentrations of resveratrol (1, 10 and 100 M) or red wine extracts (0.01, 0.1 and 1%). PC12 cells, differentiated by NGF, were treated in the same way as naive cells. Wine extracts induced neurite extensions of both naive and differentiated PC12 cells but more significantly in the latter. Resveratorol enhanced more powerfully neurite extension of differentiated PC12 cells but inhibited those of naive ones that died in its higher concentration. Resveratrol may kill tumorigenic cells but be beneficial to differentiated ones. doi:10.1016/j.neures.2009.09.778
P2-d07 Genetic trace of mouse neocortical arealization Takayoshi Inoue 1 , Youhei Terakawa 1,2 , Junko Asami 1 , Yukiko U. Inoue 1 1
National Institute of Neuroscience, NCNP, Kodaira, Japan; and Eng, Waseda Univ, Tokyo, Japan
2
Faculty of Sci
The cerebral cortex (neocortex) defined by its characteristic cytoarchitecture can be subdivided into scores of functional areas, yet how these areal organizations emerge during development and/or evolution remains elusive. Here we sought to identify ontogenetic and/or phylogenetic origin of cellular and molecular basis that facilitates neocortical arealization by using an efficient bacterial artificial chromosome (BAC) modification methodology and transgenic evaluation system in mice. Consequently, we obtained variety of BAC transgenic mouse lines in which distinct sets of developing mouse neocortical areas/layers are differentially demarcated via reporter (e.g. LacZ, EGFP, mCherry, etc.) or effector (e.g. CreERT2) gene expressions. This primarily provides evidence that separable genetic program might determine each neocortical area/layer specificity. Those animal resources should further offer new and rigid analytical frameworks in elucidating mechanism of neocortical arealization. doi:10.1016/j.neures.2009.09.779
P2-d08 Mechanism of subunit switching from NR2B to NR2C in mouse cerebellar granule cell cultures Kouichirou Iijima 1 , Haruka Abe 1,2 , Makoto Okazawa 1 , Koki Moriyoshi 3 , Shigetada Nakanishi 1 1
Systems Bio., OBI, Osaka, Japan; 2 Functional Bio., Univ of Kyoto, Kyoto, Japan; 3 Neurosci., Univ of Kyoto, Kyoto, Japan
In the cerebellar development, granule cells switch subunit composition of NMDA receptors from NR2B to NR2C, parallel to synapse formation. This switching alters properties of glutamatergic transmission, and is a key for cerebellar network maturation. We investigated mechanisms of this switching in primary cultures of mouse granule cells at the physiological KCl concentration (5 mM). Granule cells downregulated NR2B mRNA and up-regulated NR2C mRNA, parallel to extensions of neuritic processes. This dual regulation depended on neural activities sensitive to TTX, NBQX, and CPP. Suppression of dual regulation by TTX was restored by selective NMDA stimulation, but not by AMPA stimulation. Importantly, the NMDA stimulation drove switching on NMDA receptors in the cell-surface membrane. The activation of NMDA receptors thus plays a key role in functional subunit switching of NMDA receptors in maturing processes of granule cells. doi:10.1016/j.neures.2009.09.780