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Difference between corticostriatal and thalamostriatal afferents to striatal parvalbumin-producing interneuron
Abstracts ous fields, our approach may help fill neuroscience gaps between mouse and human behavioral phenotypes. doi:10.1016/j.neures.2009.09.237
O3-J2-2 Basal ganglia modulation of the firing properties of the pedunculopontine tegmental nucleus (PPN) neurons Kaoru Takakusaki 1 , Hirokazu Iwamuro 2 1 2
Department Physiol., Asahikawa Med. Coll., Asahikawa, Department Integrative Physiol., NIPS, Okazaki, Japan
Japan;
The PPN is involved in the control of higher cognitive-motor functions and basic motor functions such as posture and gait via ascending and descending projections, respectively. Because the PPN receives GABAergic efferents from the substantia nigra pars reticulata (SNr) of the basal ganglia, role of the SNr-PPN projection is a matter of concern with respect to the basal ganglia function. In this study, firing property of PPN neurons was examined in decerebrate cats. Activities of 77 neurons were recorded within and around the PPN. Stimulation of the pontine reticular formation (PRF) evoked antidromic and orthodromic responses in 29 and 55 cells, respectively. Firing of 42 cells was inhibited by stimulating the SNr. These results suggest the presence of reciprocal connections between the PPN and the PRF, which are modulated by the basal ganglia output from the SNr. The present findings are discussed in relation to deep brain stimulation (DBS) applied to the PPN for Parkinson disease patients. doi:10.1016/j.neures.2009.09.238
O3-J2-4 Difference between corticostriatal and thalamostriatal afferents to striatal parvalbumin-producing interneuron Fumino Fujiyama, Hiroshi Kameda, Takeshi Kaneko Department Morphol. Brain Sci., Kyoto University, Kyoto, Japan In addition to the two segregated striatofugal neurons, direct and indirect neurons, the neostriatum contains four kinds of interneurons. However, striatopetal innervation on the striatal interneurons has not been understood completely. To clarify the relationship between striatal parvalbumin (PV)-producing interneurons and striatopetal glutamatergic afferents, we examined the distribution of corticostriatal and thalamostriatal afferents and cholinergic striatal interneurons on the PV-producing neurons, using the transgenic mice expressing dendritic membrane-targeted GFP (green fluorescent protein) in PV-producing neurons and immunohistochemical detection of three kinds of vesicular glutamate transporters, VGLUT1, VGLUT2 and VGLUT3. With these experiments, we are getting the hint how differently the striatal local circuit processes two lines of striatopetal excitatory information. doi:10.1016/j.neures.2009.09.240
O3-J2-5 Phenotypic analysis of Rorb mutant mice Atsushi Yoshiki, Kazuyuki Mekada, Ayumi Murakami, Satoshi Oota RIKEN BioResource Center, Tsukuba, Japan We have recovered a spontaneous Rorb mutant mouse with abnormal gait and small eyes. The mutaion resided in the forth exon, and resulted in replacement of glycine by glutamic acid of isoform 1 (G83E) and isoform 2 (G94E). In order to elucidate the Rorb function, we measured gait pattern of the mutant mice by motion capture system using retroreflective markers. Immunohistological analyses of neural retina and cerebrum were also carried out. As a result of, we could detect high-resolution mutant-specific gait patterns. The specific gait pattern of homozygous mutant was caused by extreme vertical motion of limbs, revealing inefficient motor functions. Immunostaining of neural retina and cerebral tissues of homozygous mutant and wild-type mice clearly demonstrated the expression of the Rorb protein in the both genotypes. Layer-specific staining patterns of Rorb, Brn3a, Syntaxin and Calbindin were significantly altered in the neural retina, but not in the cerebrum. These findings suggest the importance of Rorb in the motor coordination and layer development of neural retina.
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O3-J3-1 Single-neuron labeling reveals parallel mitral- and tufted-cell streams in olfactory cortex Nao Ieki 1 , Kei Igarashi 1,2 , Yukie Yamaguchi 1 , Myungho An 1 , Shin Nagayama 3 , Ko Kobayakawa 4 , Reiko Kobayakawa 4 , Manabu Tanifuji 2 , Hitoshi Sakano 4 , Wei Chen 3 , Kensanku Mori 1 1
Department Physiol., University of Tokyo, Tokyo, Japan; 2 RIKEN BSI, Japan; Department Neurobio. and Anat., University of Texas Med. Sch. at Houston, USA; 4 Department Biophysi. and Biochem., Grad. Sch. of Sci., Univ of Tokyo, Tokyo, Japan 3
Individual glomeruli in the olfactory bulb (OB) represent a single type of odorant receptor (OR). The same OR signal is conveyed from the OB to the olfactory cortex (OC) in two, mitral and tufted cell, pathways. Mitral axons target entire regions of the OC, while tufted axons project only to the anterior regions. It remains unclear whether the two pathways project to distinct target areas in the anterior regions. Improved single-neuron dye-electroporation method enabled us to label entire axons and dendrites of individual functionally identified mitral and tufted cells in the mouse OB. We show that highly odor-sensitive tufted cells and odorant-mixture-sensitive mitral cells target distinct subregions in olfactory cortex. These results suggest that mitral and tufted cells set up distinct signal processing streams in the central olfactory system. doi:10.1016/j.neures.2009.09.242
O3-J3-2 Molecular basis of CO2 sensing in the mouse olfactory system Hiroo Takahashi, Sei-ichi Yoshihara, Akio Tsuboi Lab. for Mol. Biol. of Neural. System, Nara Med. Univ., Nara, Japan Olfactory sensory neurons (OSNs) expressing a given odorant receptor (OR) project axons to a pair of fixed glomeruli on the olfactory bulb to form a topographic map. Interestingly, in the most ventro-lateral region of the olfactory epithelium (OE), there is a unique subset of OSNs, termed Car2 OSNs, which express carbonic anhydrase 2 (Car2) and guanylate cyclase-D, instead of OR. Although Car2 OSNs are known to respond to CO2 and urinary peptide, a molecular mechanism regulating the neuronal development remains unrevealed. Here, we have found that BMP7 and its receptor Acvr1 are expressed specifically in Car2 OSNs, suggesting that BMP7 signaling may regulate the neuronal development in a cell-autonomous manner. We observed that Car2 expression was normal in BMP7 KO mouse embryos, although these mice died soon after birth. We cannot exclude the possible involvement of BMP7 signaling in the development of Car2 OSNs, because these neurons increase in number and maturate after birth. Then, we are in the process of expressing of BMP7/Acvr1 in the postnatal mouse OE with the lentiviral system in vivo. doi:10.1016/j.neures.2009.09.243
O3-J3-3 Genetic dissection of zebrafish olfactory circuitry mediating attractive response to amino acids Tetsuya Koide 1 , Nobuhiko Miyasaka 1 , Koichi Kawakami 2 , Yoshihiro Yoshihara 1 1
RIKEN Brain Science Institute, Japan; 2 Division of Molecular and Developmental Biology, National Institute of Genetics, Japan In fishes, amino acids are olfactory cues to elicit attractive response. However, the neural circuit underlying this olfactory behavior is not fully understood. Here, we applied the Tol2 transposon-mediated gene trap method to genetically dissect the zebrafish olfactory system in anatomical and functional aspects. Four zebrafish lines were established in which a transcription activator Gal4 was expressed in distinct subsets of olfactory sensory neurons. We expressed tetanus neurotoxin in these Gal4 lines to block synaptic transmission, analyzed their behavior to amino acid stimulus, and identified the olfactory neural pathway mediating the attractive response to amino acids. Thus, the integrated approach combining genetic, neuroanatomical, and behavioral methods enables us to elucidate neural circuit mechanism underlying a specific olfactory behavior in zebrafish.
doi:10.1016/j.neures.2009.09.241 doi:10.1016/j.neures.2009.09.244
O3-J3-4 Localized olfactory input in the mushroom bodies of Drosophila larvae Liria M. Masuda-Nakagawa 1 , Nanae Gendre 2 , Kei Ito 1 , Cahir J. O’Kane 3 , Reinhard F. Stocker 2 1
IMCB, University of Tokyo, Tokyo, Japan; 2 Department Biol., University of Fribourg, Switzerland; 3 Department Gen., University of Cambridge, UK
O3-J2-2 Basal ganglia modulation of the firing properties of the pedunculopontine tegmental nucleus (PPN) neurons Kaoru Takakusaki 1 , Hirokazu Iwamuro 2 1 2
Department Physiol., Asahikawa Med. Coll., Asahikawa, Department Integrative Physiol., NIPS, Okazaki, Japan
Japan;
The PPN is involved in the control of higher cognitive-motor functions and basic motor functions such as posture and gait via ascending and descending projections, respectively. Because the PPN receives GABAergic efferents from the substantia nigra pars reticulata (SNr) of the basal ganglia, role of the SNr-PPN projection is a matter of concern with respect to the basal ganglia function. In this study, firing property of PPN neurons was examined in decerebrate cats. Activities of 77 neurons were recorded within and around the PPN. Stimulation of the pontine reticular formation (PRF) evoked antidromic and orthodromic responses in 29 and 55 cells, respectively. Firing of 42 cells was inhibited by stimulating the SNr. These results suggest the presence of reciprocal connections between the PPN and the PRF, which are modulated by the basal ganglia output from the SNr. The present findings are discussed in relation to deep brain stimulation (DBS) applied to the PPN for Parkinson disease patients. doi:10.1016/j.neures.2009.09.238
O3-J2-4 Difference between corticostriatal and thalamostriatal afferents to striatal parvalbumin-producing interneuron Fumino Fujiyama, Hiroshi Kameda, Takeshi Kaneko Department Morphol. Brain Sci., Kyoto University, Kyoto, Japan In addition to the two segregated striatofugal neurons, direct and indirect neurons, the neostriatum contains four kinds of interneurons. However, striatopetal innervation on the striatal interneurons has not been understood completely. To clarify the relationship between striatal parvalbumin (PV)-producing interneurons and striatopetal glutamatergic afferents, we examined the distribution of corticostriatal and thalamostriatal afferents and cholinergic striatal interneurons on the PV-producing neurons, using the transgenic mice expressing dendritic membrane-targeted GFP (green fluorescent protein) in PV-producing neurons and immunohistochemical detection of three kinds of vesicular glutamate transporters, VGLUT1, VGLUT2 and VGLUT3. With these experiments, we are getting the hint how differently the striatal local circuit processes two lines of striatopetal excitatory information. doi:10.1016/j.neures.2009.09.240
O3-J2-5 Phenotypic analysis of Rorb mutant mice Atsushi Yoshiki, Kazuyuki Mekada, Ayumi Murakami, Satoshi Oota RIKEN BioResource Center, Tsukuba, Japan We have recovered a spontaneous Rorb mutant mouse with abnormal gait and small eyes. The mutaion resided in the forth exon, and resulted in replacement of glycine by glutamic acid of isoform 1 (G83E) and isoform 2 (G94E). In order to elucidate the Rorb function, we measured gait pattern of the mutant mice by motion capture system using retroreflective markers. Immunohistological analyses of neural retina and cerebrum were also carried out. As a result of, we could detect high-resolution mutant-specific gait patterns. The specific gait pattern of homozygous mutant was caused by extreme vertical motion of limbs, revealing inefficient motor functions. Immunostaining of neural retina and cerebral tissues of homozygous mutant and wild-type mice clearly demonstrated the expression of the Rorb protein in the both genotypes. Layer-specific staining patterns of Rorb, Brn3a, Syntaxin and Calbindin were significantly altered in the neural retina, but not in the cerebrum. These findings suggest the importance of Rorb in the motor coordination and layer development of neural retina.
S71
O3-J3-1 Single-neuron labeling reveals parallel mitral- and tufted-cell streams in olfactory cortex Nao Ieki 1 , Kei Igarashi 1,2 , Yukie Yamaguchi 1 , Myungho An 1 , Shin Nagayama 3 , Ko Kobayakawa 4 , Reiko Kobayakawa 4 , Manabu Tanifuji 2 , Hitoshi Sakano 4 , Wei Chen 3 , Kensanku Mori 1 1
Department Physiol., University of Tokyo, Tokyo, Japan; 2 RIKEN BSI, Japan; Department Neurobio. and Anat., University of Texas Med. Sch. at Houston, USA; 4 Department Biophysi. and Biochem., Grad. Sch. of Sci., Univ of Tokyo, Tokyo, Japan 3
Individual glomeruli in the olfactory bulb (OB) represent a single type of odorant receptor (OR). The same OR signal is conveyed from the OB to the olfactory cortex (OC) in two, mitral and tufted cell, pathways. Mitral axons target entire regions of the OC, while tufted axons project only to the anterior regions. It remains unclear whether the two pathways project to distinct target areas in the anterior regions. Improved single-neuron dye-electroporation method enabled us to label entire axons and dendrites of individual functionally identified mitral and tufted cells in the mouse OB. We show that highly odor-sensitive tufted cells and odorant-mixture-sensitive mitral cells target distinct subregions in olfactory cortex. These results suggest that mitral and tufted cells set up distinct signal processing streams in the central olfactory system. doi:10.1016/j.neures.2009.09.242
O3-J3-2 Molecular basis of CO2 sensing in the mouse olfactory system Hiroo Takahashi, Sei-ichi Yoshihara, Akio Tsuboi Lab. for Mol. Biol. of Neural. System, Nara Med. Univ., Nara, Japan Olfactory sensory neurons (OSNs) expressing a given odorant receptor (OR) project axons to a pair of fixed glomeruli on the olfactory bulb to form a topographic map. Interestingly, in the most ventro-lateral region of the olfactory epithelium (OE), there is a unique subset of OSNs, termed Car2 OSNs, which express carbonic anhydrase 2 (Car2) and guanylate cyclase-D, instead of OR. Although Car2 OSNs are known to respond to CO2 and urinary peptide, a molecular mechanism regulating the neuronal development remains unrevealed. Here, we have found that BMP7 and its receptor Acvr1 are expressed specifically in Car2 OSNs, suggesting that BMP7 signaling may regulate the neuronal development in a cell-autonomous manner. We observed that Car2 expression was normal in BMP7 KO mouse embryos, although these mice died soon after birth. We cannot exclude the possible involvement of BMP7 signaling in the development of Car2 OSNs, because these neurons increase in number and maturate after birth. Then, we are in the process of expressing of BMP7/Acvr1 in the postnatal mouse OE with the lentiviral system in vivo. doi:10.1016/j.neures.2009.09.243
O3-J3-3 Genetic dissection of zebrafish olfactory circuitry mediating attractive response to amino acids Tetsuya Koide 1 , Nobuhiko Miyasaka 1 , Koichi Kawakami 2 , Yoshihiro Yoshihara 1 1
RIKEN Brain Science Institute, Japan; 2 Division of Molecular and Developmental Biology, National Institute of Genetics, Japan In fishes, amino acids are olfactory cues to elicit attractive response. However, the neural circuit underlying this olfactory behavior is not fully understood. Here, we applied the Tol2 transposon-mediated gene trap method to genetically dissect the zebrafish olfactory system in anatomical and functional aspects. Four zebrafish lines were established in which a transcription activator Gal4 was expressed in distinct subsets of olfactory sensory neurons. We expressed tetanus neurotoxin in these Gal4 lines to block synaptic transmission, analyzed their behavior to amino acid stimulus, and identified the olfactory neural pathway mediating the attractive response to amino acids. Thus, the integrated approach combining genetic, neuroanatomical, and behavioral methods enables us to elucidate neural circuit mechanism underlying a specific olfactory behavior in zebrafish.
doi:10.1016/j.neures.2009.09.241 doi:10.1016/j.neures.2009.09.244
O3-J3-4 Localized olfactory input in the mushroom bodies of Drosophila larvae Liria M. Masuda-Nakagawa 1 , Nanae Gendre 2 , Kei Ito 1 , Cahir J. O’Kane 3 , Reinhard F. Stocker 2 1
IMCB, University of Tokyo, Tokyo, Japan; 2 Department Biol., University of Fribourg, Switzerland; 3 Department Gen., University of Cambridge, UK