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Behavioral state-dependent change of granule-to-mitral inhibition in the rat olfactory bulb
Abstracts / Neuroscience Research 58S (2007) S1–S244
O2P-JØ6 G protein-coupled novel temperature sensing mechanism
Kuhara 1 ,
Masatoshi Okumura 1 , Matsumoto 1 , Ikue Mori 1
Kimura 1,2,3 ,
S67
O2P-JØ9 Decoding an innate aversive quality from an odor map in the mouse olfactory bulb
Atsushi Koutarou D. Kunihiro 1 Department of Biology, Nagoya University, Japan; 2 Nagoya University, Japan; 3 Present address: National Institute of Genetics, Japan
Ko Kobayakawa 1 , Reiko Kobayakawa 1 , Kensaku Mori 2 , Hitoshi Sakano 1 1 Department of Biophysics and Biochemistry, University of Tokyo, Tokyo, Japan; 2 Department of Physiology, Graduate School of Medicine, The University of Tokyo, Japan
Animal receives environmental stimuli such as light, smell, and temperature by using sensory neurons. While light and smell are received by G protein-coupled receptors, temperature is received by TRP channel. Here we show novel temperature sensing mechanism through G proteincoupled signaling in C. elegans. The loss-of-function mutation in inhibitor of G protein, RGS, encoded by eat-16 gene led to abnormal thermotaxis, which was caused by malfunction of AWC sensory neuron. Thermotactic defect in eat-16 mutant was suppressed by the mutations in G protein (ODR-3)-coupled signaling in AWC. Calcium imaging revealed that AWC neuron in wild-type was activated by temperature changes. By contrast, AWC activity was significantly decreased in the G protein ODR-3 mutant. These results suggest that G protein-coupled signaling is required for thermosensation. We also found that TRP channel OSM-9 localizing at AWC cell body is involved in continuity of neural response.
The binding signals of odorants received in the olfactory epithelium (OE) are converted to a topographic map of activated glomeruli in the OB. In order to study how the odor map is decoded, we generated mutant mice in which OSNs in a specific area of the OE were depleted by targeted expression of the diphtheria toxin gene. In the zone 1 (dorso-medial zone)-depleted animal, the antero-dorsal domain in the OB was devoid of axon termini and without glomerular structures. The zone 1-depleted mouse displayed no aversive responses to aversive compounds, although it was capable of detecting and discriminating them. In contrast, the class II-depleted mouse, in which the glomeruli were formed only in the most antero-dorsal part of zone 1, demonstrated aversive behavior. These results indicate that zone 1 glomeruli in the OB have a separate role in decoding the odor map, and that there may be genetically programmed, hard-wired neural circuits for innately aversive odorants.
Research funds: KAKENHI 18770005
O2P-JØ7 An LCR H for the mouse odorant receptor (OR) genes acts in cis, and not in trans
O2P-J1Ø Behavioral state-dependent change of granule-tomitral inhibition in the rat olfactory bulb
Hirofumi Nishizumi, Kohei Kumasaka, Hitoshi Sakano Department of Biophysics & Biochemistry, University of Tokyo, Tokyo, Japan
Yusuke Tsuno, Hideki Kashiwadani, Kensaku Mori Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
In the mouse, over 1000 OR genes are clustered at 44 different loci among most of the chromosomes. We have previously reported a locus control region (LCR) as a 2 kb homology (H) sequence conserved between the mouse and human, that regulates the MOR28 cluster. Now, we narrowed down the essential sequences in the H to a 124 bp region. Mutation analyses of the 124 bp region revealed 2 homeodomain sequences that are essential for the H activity. Recently, Axel’s group reported that the H may act not only in cis but also in trans. A trans-acting LCR may help ensure the 1 neuron-1 OR rule if we assume that the H is the only one LCR in the OR gene family. However, our knockout experiment demonstrated that deletion of the H abolished the expression of 3 proximal zone 4 genes in the MOR28 cluster, indicating the presence of another LCR for the downstream zone 1 genes. No other OR gene clusters, including the other allele of the MOR28 cluster, were affected by the H-knockout. Based on these results, we propose that the OR genes are regulated by multiple LCRs that act in cis, and not in trans.
Behavioral states regulate information processing modes at local neuronal circuits, which are reflected by the change in the local EEG pattern. Here we asked whether dendrodendritic synaptic interactions in the olfactory bulb depend on the brain states. In the brain of urethane-anesthetized rats that showed periodic alternation of neocortical EEG pattern, granuleto-mitral dendrodendritic synaptic inhibition was much larger during slow-wave state than during fast-wave state. The state-dependent shift in the dendrodendritic inhibition was observed also in freely behaving rats, being greatly enhanced during slow-wave sleep state compared to awake states. These results provide the evidence for the behavioral statedependent modulation of the dendrodendritic synaptic interaction and suggest that olfactory bulb networks can engage in different information processing modes via the states of the dendrodendritic inhibition. Research funds: KAKENHI (18100004, 17023012), JSPS Research Fellowships
Research funds: KAKENHI (17570172)
O2P-JØ8 A new candidate pheromone receptor contributing to the male courtship behavior of Drosophila Masayuki Koganezawa, Daisuke Yamamoto Graduate School of Life Sciences, Tohoku University, Sendai, Japan
O2P-J12 The re-presentation of conditioned stimulus after acquisition of conditioned taste aversion increase ventral pallidum GABA release in rats Tadashi Inui 1 , Tsuyoshi Shimura 1 , Takashi Yamamoto 2 Department of Behavioral Physiology, Graduate School of Human Sciences, Osaka University, Osaka, Japan; 2 Graduate School of Dentistry, Osaka University, Osaka, Japan
1
Courtship behavior of Drosophila heavily depends on chemoreception. A gustatory receptor (Gr) gene, Gr32a, is a candidate for pheromone receptor. We report here that male courtship behavior is impaired when the Gr32a-expressing neurons are prevented from functioning. To block synaptic transmission in Gr32a-expressing neurons, the tetanus toxin (TNT) was expressed under the control of the Gr32a promoter (Gr32a > TNT) The depression of Gr32a-expressing neuron activities had no significant effects on the basic courtship activity. However, it leads to a specific defect in the wing extension/vibration step during the courtship. The control male flies normally extend one of their wings while another wing is rigidly placed in its closed position. On the contrary, the Gr32a > TNT flies often extend both wings simultaneously. The present result suggests that male flies determine which of the wings to extend or to close based on the lateralized pheromonal input from Gr32a-expressing neurons. Research funds: This work was supported by Grant-in-Aid for Specially Promoted Research (18002012) from MEXT to D.Y.
Previous our studies provided the evidence that GABAA receptors in the ventral pallidum (VP) are involved in palatability shift from ingestive to aversive in conditioned taste aversion (CTA). Present studies explored the possibility that the re-presentation of CS after acquisition of CTA might affect the GABA releasein the VP. Initially, rats received a pairing of 5 mM saccharin (CS) and an i.p. injection of 0.15 M LiCl (conditioned group) or saline (unconditioned group). After this conditioning, microdialysis was carried out in the rats re-presented with CS via an intra-oral cannula. GABA was measured by HPLC with OPA-sulfite precolumn derivatization. The CS re-presentation rapidly induced aversive behaviors in conditioned group, but not in unconditioned group. The conditioned group showed significant increase in the GABA release (by 135%), the unconditioned group did not. These data suggest that palatability shift as a function of CTA increases the VP GABA release. Research funds: KAKENHI (17730431)
O2P-JØ6 G protein-coupled novel temperature sensing mechanism
Kuhara 1 ,
Masatoshi Okumura 1 , Matsumoto 1 , Ikue Mori 1
Kimura 1,2,3 ,
S67
O2P-JØ9 Decoding an innate aversive quality from an odor map in the mouse olfactory bulb
Atsushi Koutarou D. Kunihiro 1 Department of Biology, Nagoya University, Japan; 2 Nagoya University, Japan; 3 Present address: National Institute of Genetics, Japan
Ko Kobayakawa 1 , Reiko Kobayakawa 1 , Kensaku Mori 2 , Hitoshi Sakano 1 1 Department of Biophysics and Biochemistry, University of Tokyo, Tokyo, Japan; 2 Department of Physiology, Graduate School of Medicine, The University of Tokyo, Japan
Animal receives environmental stimuli such as light, smell, and temperature by using sensory neurons. While light and smell are received by G protein-coupled receptors, temperature is received by TRP channel. Here we show novel temperature sensing mechanism through G proteincoupled signaling in C. elegans. The loss-of-function mutation in inhibitor of G protein, RGS, encoded by eat-16 gene led to abnormal thermotaxis, which was caused by malfunction of AWC sensory neuron. Thermotactic defect in eat-16 mutant was suppressed by the mutations in G protein (ODR-3)-coupled signaling in AWC. Calcium imaging revealed that AWC neuron in wild-type was activated by temperature changes. By contrast, AWC activity was significantly decreased in the G protein ODR-3 mutant. These results suggest that G protein-coupled signaling is required for thermosensation. We also found that TRP channel OSM-9 localizing at AWC cell body is involved in continuity of neural response.
The binding signals of odorants received in the olfactory epithelium (OE) are converted to a topographic map of activated glomeruli in the OB. In order to study how the odor map is decoded, we generated mutant mice in which OSNs in a specific area of the OE were depleted by targeted expression of the diphtheria toxin gene. In the zone 1 (dorso-medial zone)-depleted animal, the antero-dorsal domain in the OB was devoid of axon termini and without glomerular structures. The zone 1-depleted mouse displayed no aversive responses to aversive compounds, although it was capable of detecting and discriminating them. In contrast, the class II-depleted mouse, in which the glomeruli were formed only in the most antero-dorsal part of zone 1, demonstrated aversive behavior. These results indicate that zone 1 glomeruli in the OB have a separate role in decoding the odor map, and that there may be genetically programmed, hard-wired neural circuits for innately aversive odorants.
Research funds: KAKENHI 18770005
O2P-JØ7 An LCR H for the mouse odorant receptor (OR) genes acts in cis, and not in trans
O2P-J1Ø Behavioral state-dependent change of granule-tomitral inhibition in the rat olfactory bulb
Hirofumi Nishizumi, Kohei Kumasaka, Hitoshi Sakano Department of Biophysics & Biochemistry, University of Tokyo, Tokyo, Japan
Yusuke Tsuno, Hideki Kashiwadani, Kensaku Mori Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
In the mouse, over 1000 OR genes are clustered at 44 different loci among most of the chromosomes. We have previously reported a locus control region (LCR) as a 2 kb homology (H) sequence conserved between the mouse and human, that regulates the MOR28 cluster. Now, we narrowed down the essential sequences in the H to a 124 bp region. Mutation analyses of the 124 bp region revealed 2 homeodomain sequences that are essential for the H activity. Recently, Axel’s group reported that the H may act not only in cis but also in trans. A trans-acting LCR may help ensure the 1 neuron-1 OR rule if we assume that the H is the only one LCR in the OR gene family. However, our knockout experiment demonstrated that deletion of the H abolished the expression of 3 proximal zone 4 genes in the MOR28 cluster, indicating the presence of another LCR for the downstream zone 1 genes. No other OR gene clusters, including the other allele of the MOR28 cluster, were affected by the H-knockout. Based on these results, we propose that the OR genes are regulated by multiple LCRs that act in cis, and not in trans.
Behavioral states regulate information processing modes at local neuronal circuits, which are reflected by the change in the local EEG pattern. Here we asked whether dendrodendritic synaptic interactions in the olfactory bulb depend on the brain states. In the brain of urethane-anesthetized rats that showed periodic alternation of neocortical EEG pattern, granuleto-mitral dendrodendritic synaptic inhibition was much larger during slow-wave state than during fast-wave state. The state-dependent shift in the dendrodendritic inhibition was observed also in freely behaving rats, being greatly enhanced during slow-wave sleep state compared to awake states. These results provide the evidence for the behavioral statedependent modulation of the dendrodendritic synaptic interaction and suggest that olfactory bulb networks can engage in different information processing modes via the states of the dendrodendritic inhibition. Research funds: KAKENHI (18100004, 17023012), JSPS Research Fellowships
Research funds: KAKENHI (17570172)
O2P-JØ8 A new candidate pheromone receptor contributing to the male courtship behavior of Drosophila Masayuki Koganezawa, Daisuke Yamamoto Graduate School of Life Sciences, Tohoku University, Sendai, Japan
O2P-J12 The re-presentation of conditioned stimulus after acquisition of conditioned taste aversion increase ventral pallidum GABA release in rats Tadashi Inui 1 , Tsuyoshi Shimura 1 , Takashi Yamamoto 2 Department of Behavioral Physiology, Graduate School of Human Sciences, Osaka University, Osaka, Japan; 2 Graduate School of Dentistry, Osaka University, Osaka, Japan
1
Courtship behavior of Drosophila heavily depends on chemoreception. A gustatory receptor (Gr) gene, Gr32a, is a candidate for pheromone receptor. We report here that male courtship behavior is impaired when the Gr32a-expressing neurons are prevented from functioning. To block synaptic transmission in Gr32a-expressing neurons, the tetanus toxin (TNT) was expressed under the control of the Gr32a promoter (Gr32a > TNT) The depression of Gr32a-expressing neuron activities had no significant effects on the basic courtship activity. However, it leads to a specific defect in the wing extension/vibration step during the courtship. The control male flies normally extend one of their wings while another wing is rigidly placed in its closed position. On the contrary, the Gr32a > TNT flies often extend both wings simultaneously. The present result suggests that male flies determine which of the wings to extend or to close based on the lateralized pheromonal input from Gr32a-expressing neurons. Research funds: This work was supported by Grant-in-Aid for Specially Promoted Research (18002012) from MEXT to D.Y.
Previous our studies provided the evidence that GABAA receptors in the ventral pallidum (VP) are involved in palatability shift from ingestive to aversive in conditioned taste aversion (CTA). Present studies explored the possibility that the re-presentation of CS after acquisition of CTA might affect the GABA releasein the VP. Initially, rats received a pairing of 5 mM saccharin (CS) and an i.p. injection of 0.15 M LiCl (conditioned group) or saline (unconditioned group). After this conditioning, microdialysis was carried out in the rats re-presented with CS via an intra-oral cannula. GABA was measured by HPLC with OPA-sulfite precolumn derivatization. The CS re-presentation rapidly induced aversive behaviors in conditioned group, but not in unconditioned group. The conditioned group showed significant increase in the GABA release (by 135%), the unconditioned group did not. These data suggest that palatability shift as a function of CTA increases the VP GABA release. Research funds: KAKENHI (17730431)