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Mitral and tufted cells differ in concentration threshold and temporal profiles of odor response in the mouse olfactory bulb
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Abstracts / Neuroscience Research 71S (2011) e108–e415
whether the body weight level affected enhanced sucrose preference induced by a modified taste-nutrition association paradigm in C57BL/6 male mice. Under daily 19-h water deprivation, food restricted-mice were allowed to consume one of two sweeteners: a caloric 0.15 M sucrose (Suc) in odd days or an artificial non-caloric sweetener, 5 mM sodium saccharin (Sac), in even days (alternative conditioning procedure). As their body weights were reduced to about 80% of their original level, the amount of Suc intake remarkably increased, while that of Sac intake unchanged. When their body weights were recovered to the original level, the preference for Suc was abruptly dropped down to the similar preference level for Sac (Saltatory suppression of Suc preference). The similar result appeared even when separate mouse group were simultaneously given 0.15 M Suc and 5 mM Sac using two-bottle method with the same food restriction. We examined the effects of lesions of the somatosensory area related to four limbs in the cerebral cortex on the saltatory suppression of Suc preference. Lesioned mice did not exhibit the saltatory suppression of Suc preference. In Experiment 2, separate mice group was conditioned to acquire learned aversion to the Suc and were allowed to consume the Suc solution every day with food restriction. Their Suc intake was increased as energetic source to compensate caloric deficiency. However, the Suc intake gradually decreased in a few days after their body weight recovered to their original level, resulting in the preference for Suc lowered to the similar level in ad libitum fed-mice. These results indicate that the integrative neural mechanism controls the caloric sugar preference through neural crosstalk among nutritional need, homeostatic energetic status, taste-related memory and cognitive function.
convey neural activation evoked by the lateral olfactory tract (LOT) stimulation: a medial pathway from the PC to the AC, and a lateral pathway from the PC to the lateral EC along the rhinal sulcus (Kajiwara et al., Eur J Neurosci 2007). Interestingly, in addition to being activated directly via the medial pathway, AC was activated a second time via activity that propagated from the lateral EC. To assess the physiological property of the olfactory network, we examined the dependency of stimulus intensity and frequency on the spatiotemporal patterns of LOT-evoked neural activity especially via these three neural pathways (PC-AC, PC-EC and EC-AC). When we decreased the intensity of the electrical stimulation to the LOT, only a subtle response in the EC-AC pathway was observed, though PC was apparently activated. However, we found that the amplitude of neural responses recorded in the pathway from the EC to the AC was significantly enhanced under the influence of the repetitive stimulation to the LOT at the frequency of 10 Hz. In addition to the imaging study, laminar profiles of evoked field potentials were recorded in the AC using a multichannel silicon probe. Current source density analysis performed on the field responses revealed that (i) EC activities input to the deeper cortical area in the layer II/III of the AC than the area to which PC activities input, (ii) 10 Hz stimulation to the LOT produced a large current-sink in the layer III/IV of the AC. Judging from the comparison of peak latencies between the field potentials of the AC and basolateral amygdala (AMG), it seems very possible that the neural activity observed in the AC was transmitted to the AMG. Research fund: KAKENHI(21700389). doi:10.1016/j.neures.2011.07.1570
doi:10.1016/j.neures.2011.07.1568
P4-j14 Involvement of mGluRs in umami detection in mice Yoko Kusuhara 1,2 , Keiko Yasumatsu 1 , Tadahiro Ohkuri 1 , Ryusuke Yoshida 1 , Katsumasa Maeda 2 , Yuzo Ninomiya 1 1
Section of Oral Neurosci., Grad. Sch. of Dent., Kyushu Univ., Fukuoka, Japan 2 Section of Periodontol., Div. of Rehabilitation, Faculty of Dent. Sci., Kyushu Univ., Fukuoka, Japan Monosodium l-Glutamate (MSG) elicits umami taste that is one of the five basic qualities. Recent molecular studies have identified several candidate receptors for umami in taste cells, such as the hetero dimer T1R1/T1R3 and mGluRs (brain-GluR1, brain mGluR4, taste-mGluR1, and taste-mGluR4). Previous studies with T1R-KO mice reported some controversial results. One study showed that behavioral and chorda tympani (CT) nerve responses to umami alone, and both umami and sweet compounds were abolished in T1R1-KO and T1R3-KO mice, respectively, whereas T1R3-KO mice in another study showed largely reduced behavioral and CT responses to umami but almost no change in umami responses of the glossopharyngeal (GL) nerve, which is thought to be more important in detection of umami taste than the CT. The latter study indicates a possibility of existence of multiple umami receptors. To further test the possibility, here, we used T1R1-KO mice and examined potential effects of antagonists of mGluRs (AIDA for group I mGluRs; CPPG for group III mGluRs) on behavioral and CT and GL responses to MSG with amiloride and other taste compounds. The results showed that T1R1-KO mice exhibited complete loss of synergistic responses to MSG and IMP but substantial residual responses to MSG alone in both CT and GL nerves. The residual responses to MSG were significantly inhibited by addition of AIDA or CPPG. In behavioral experiments with CTA (conditioned taste aversion) paradigm, we conditioned mice to avoid 0.3 M MSG, and found that the conditioned mice exhibited clear avoidance to MSG, but not to other basic taste stimuli, indicating that mice can detect umami taste. Comparable with electrophysiological results, the number of licks of mice to MSG solution increased by addition of AIDA or CPPG, in a concentration-dependent manner. These results suggest that mGluRs may be involved in the residual responses to MSG in T1R1-KO mice. doi:10.1016/j.neures.2011.07.1569
P4-j15 Repetitive olfactory nerve stimulation induced enhancement of neural activities in the amygdaloid cortex of guinea pig isolated whole brain Riichi Kajiwara 1 , Takashi Tominaga 2 , Ichiro Takashima 3 1
Biomed. Res. Inst., AIST, Tsukuba, Japan 2 Dept. Neurophys., Tokushima Bunri Univ., Sanuki, Japan 3 Human Tech RI, AIST, Tsukuba, Japan
The amygdaloid cortex (AC) and the entorhinal cortex (EC) are activated by the olfactory bulb directly and indirectly via the piriform cortex (PC). Using a voltage-sensitive dye imaging technique in the guinea pig isolated whole brain in vitro preparation, actually, we observed two distinct pathways that
P4-j16 Mitral and tufted cells differ in concentration threshold and temporal profiles of odor response in the mouse olfactory bulb Nao Ieki 1,2 , Kei Igarashi 1 , Kensaku Mori 1 1
Dept. Physiology, Grad. Sch. of Med., Tokyo Univ., Tokyo, Japan Research Fellow
2
JPSP
In the mammalian olfactory bulb, each glomerulus has 4 types of projection neurons; external tufted cell (eTC), middle tufted cell (mTC), internal tufted cell (iTC), and mitral cell (MC). However, the functional difference between these projection neurons is not well understood. By combining single-neuron recording and labeling methods in anesthetized mice, we investigated whether each types of projection neuron have specific odor response properties and distinct axonal projection patterns in the olfactory cortex. Here we show that odor concentration threshold was lower, and the temporal profile of the odor response was faster and briefer in TCs than in MCs. Also, accuracy of the response to the rapid change in the odor concentration was higher in eTCs than in MCs. Moreover, axonal projection patterns were segregated in TCs and MCs throughout the olfactory cortex areas. These result suggest that eTCs form a temporally rapid and low odorant discriminability channel, and mitral cells constitute a temporally slow but high odorant discriminability channel. doi:10.1016/j.neures.2011.07.1571
P4-j17 Neural circuit mechanism underlying behavioral transition from attack to parenting toward pups in male mice Kashiko Tachikawa 1 , Sayaka Komatsu 1 , Sayaka Shindo 1 , Yoshihiro Yoshihara 2 , Kumi Kuroda 1 1
Kuroda Research Unit, RIKEN BSI, Wako, Japan Synapse, RIKEN BSI, Wako, Japan
2
Lab Neurobiology of
Sexually-naïve male mice show robust aggressive behaviors toward pups. However, during the cohabituation period with pregnant females after their first mating, the male mice gradually lose aggressiveness toward pups. Subsequently, when these males become fathers, they display parental (paternal) behaviors toward pups, similar to the maternal behaviors by mothers. To elucidate the neural circuit mechanism underlying this behavioral transition, we examined the brain regions differently activated by pup exposure between sexually-naïve male mice and father mice, using c-Fos expression as a marker for neuronal activation. We found that, upon pup exposure, the brain regions along the vomeronasal neural pathway, which mediates signal transduction, coding, and processing of pheromonal information, were more strongly activated in sexually-naïve male mice than those in father’s. Surgical ablation of the vomeronasal organ resulted in abrogation of the aggressive behaviors toward pups in sexually-naïve male mice and further led to expression of parental behaviors in half of them. These results suggest that the chemical cues inducing aggressive behaviors toward pups are received by
Abstracts / Neuroscience Research 71S (2011) e108–e415
whether the body weight level affected enhanced sucrose preference induced by a modified taste-nutrition association paradigm in C57BL/6 male mice. Under daily 19-h water deprivation, food restricted-mice were allowed to consume one of two sweeteners: a caloric 0.15 M sucrose (Suc) in odd days or an artificial non-caloric sweetener, 5 mM sodium saccharin (Sac), in even days (alternative conditioning procedure). As their body weights were reduced to about 80% of their original level, the amount of Suc intake remarkably increased, while that of Sac intake unchanged. When their body weights were recovered to the original level, the preference for Suc was abruptly dropped down to the similar preference level for Sac (Saltatory suppression of Suc preference). The similar result appeared even when separate mouse group were simultaneously given 0.15 M Suc and 5 mM Sac using two-bottle method with the same food restriction. We examined the effects of lesions of the somatosensory area related to four limbs in the cerebral cortex on the saltatory suppression of Suc preference. Lesioned mice did not exhibit the saltatory suppression of Suc preference. In Experiment 2, separate mice group was conditioned to acquire learned aversion to the Suc and were allowed to consume the Suc solution every day with food restriction. Their Suc intake was increased as energetic source to compensate caloric deficiency. However, the Suc intake gradually decreased in a few days after their body weight recovered to their original level, resulting in the preference for Suc lowered to the similar level in ad libitum fed-mice. These results indicate that the integrative neural mechanism controls the caloric sugar preference through neural crosstalk among nutritional need, homeostatic energetic status, taste-related memory and cognitive function.
convey neural activation evoked by the lateral olfactory tract (LOT) stimulation: a medial pathway from the PC to the AC, and a lateral pathway from the PC to the lateral EC along the rhinal sulcus (Kajiwara et al., Eur J Neurosci 2007). Interestingly, in addition to being activated directly via the medial pathway, AC was activated a second time via activity that propagated from the lateral EC. To assess the physiological property of the olfactory network, we examined the dependency of stimulus intensity and frequency on the spatiotemporal patterns of LOT-evoked neural activity especially via these three neural pathways (PC-AC, PC-EC and EC-AC). When we decreased the intensity of the electrical stimulation to the LOT, only a subtle response in the EC-AC pathway was observed, though PC was apparently activated. However, we found that the amplitude of neural responses recorded in the pathway from the EC to the AC was significantly enhanced under the influence of the repetitive stimulation to the LOT at the frequency of 10 Hz. In addition to the imaging study, laminar profiles of evoked field potentials were recorded in the AC using a multichannel silicon probe. Current source density analysis performed on the field responses revealed that (i) EC activities input to the deeper cortical area in the layer II/III of the AC than the area to which PC activities input, (ii) 10 Hz stimulation to the LOT produced a large current-sink in the layer III/IV of the AC. Judging from the comparison of peak latencies between the field potentials of the AC and basolateral amygdala (AMG), it seems very possible that the neural activity observed in the AC was transmitted to the AMG. Research fund: KAKENHI(21700389). doi:10.1016/j.neures.2011.07.1570
doi:10.1016/j.neures.2011.07.1568
P4-j14 Involvement of mGluRs in umami detection in mice Yoko Kusuhara 1,2 , Keiko Yasumatsu 1 , Tadahiro Ohkuri 1 , Ryusuke Yoshida 1 , Katsumasa Maeda 2 , Yuzo Ninomiya 1 1
Section of Oral Neurosci., Grad. Sch. of Dent., Kyushu Univ., Fukuoka, Japan 2 Section of Periodontol., Div. of Rehabilitation, Faculty of Dent. Sci., Kyushu Univ., Fukuoka, Japan Monosodium l-Glutamate (MSG) elicits umami taste that is one of the five basic qualities. Recent molecular studies have identified several candidate receptors for umami in taste cells, such as the hetero dimer T1R1/T1R3 and mGluRs (brain-GluR1, brain mGluR4, taste-mGluR1, and taste-mGluR4). Previous studies with T1R-KO mice reported some controversial results. One study showed that behavioral and chorda tympani (CT) nerve responses to umami alone, and both umami and sweet compounds were abolished in T1R1-KO and T1R3-KO mice, respectively, whereas T1R3-KO mice in another study showed largely reduced behavioral and CT responses to umami but almost no change in umami responses of the glossopharyngeal (GL) nerve, which is thought to be more important in detection of umami taste than the CT. The latter study indicates a possibility of existence of multiple umami receptors. To further test the possibility, here, we used T1R1-KO mice and examined potential effects of antagonists of mGluRs (AIDA for group I mGluRs; CPPG for group III mGluRs) on behavioral and CT and GL responses to MSG with amiloride and other taste compounds. The results showed that T1R1-KO mice exhibited complete loss of synergistic responses to MSG and IMP but substantial residual responses to MSG alone in both CT and GL nerves. The residual responses to MSG were significantly inhibited by addition of AIDA or CPPG. In behavioral experiments with CTA (conditioned taste aversion) paradigm, we conditioned mice to avoid 0.3 M MSG, and found that the conditioned mice exhibited clear avoidance to MSG, but not to other basic taste stimuli, indicating that mice can detect umami taste. Comparable with electrophysiological results, the number of licks of mice to MSG solution increased by addition of AIDA or CPPG, in a concentration-dependent manner. These results suggest that mGluRs may be involved in the residual responses to MSG in T1R1-KO mice. doi:10.1016/j.neures.2011.07.1569
P4-j15 Repetitive olfactory nerve stimulation induced enhancement of neural activities in the amygdaloid cortex of guinea pig isolated whole brain Riichi Kajiwara 1 , Takashi Tominaga 2 , Ichiro Takashima 3 1
Biomed. Res. Inst., AIST, Tsukuba, Japan 2 Dept. Neurophys., Tokushima Bunri Univ., Sanuki, Japan 3 Human Tech RI, AIST, Tsukuba, Japan
The amygdaloid cortex (AC) and the entorhinal cortex (EC) are activated by the olfactory bulb directly and indirectly via the piriform cortex (PC). Using a voltage-sensitive dye imaging technique in the guinea pig isolated whole brain in vitro preparation, actually, we observed two distinct pathways that
P4-j16 Mitral and tufted cells differ in concentration threshold and temporal profiles of odor response in the mouse olfactory bulb Nao Ieki 1,2 , Kei Igarashi 1 , Kensaku Mori 1 1
Dept. Physiology, Grad. Sch. of Med., Tokyo Univ., Tokyo, Japan Research Fellow
2
JPSP
In the mammalian olfactory bulb, each glomerulus has 4 types of projection neurons; external tufted cell (eTC), middle tufted cell (mTC), internal tufted cell (iTC), and mitral cell (MC). However, the functional difference between these projection neurons is not well understood. By combining single-neuron recording and labeling methods in anesthetized mice, we investigated whether each types of projection neuron have specific odor response properties and distinct axonal projection patterns in the olfactory cortex. Here we show that odor concentration threshold was lower, and the temporal profile of the odor response was faster and briefer in TCs than in MCs. Also, accuracy of the response to the rapid change in the odor concentration was higher in eTCs than in MCs. Moreover, axonal projection patterns were segregated in TCs and MCs throughout the olfactory cortex areas. These result suggest that eTCs form a temporally rapid and low odorant discriminability channel, and mitral cells constitute a temporally slow but high odorant discriminability channel. doi:10.1016/j.neures.2011.07.1571
P4-j17 Neural circuit mechanism underlying behavioral transition from attack to parenting toward pups in male mice Kashiko Tachikawa 1 , Sayaka Komatsu 1 , Sayaka Shindo 1 , Yoshihiro Yoshihara 2 , Kumi Kuroda 1 1
Kuroda Research Unit, RIKEN BSI, Wako, Japan Synapse, RIKEN BSI, Wako, Japan
2
Lab Neurobiology of
Sexually-naïve male mice show robust aggressive behaviors toward pups. However, during the cohabituation period with pregnant females after their first mating, the male mice gradually lose aggressiveness toward pups. Subsequently, when these males become fathers, they display parental (paternal) behaviors toward pups, similar to the maternal behaviors by mothers. To elucidate the neural circuit mechanism underlying this behavioral transition, we examined the brain regions differently activated by pup exposure between sexually-naïve male mice and father mice, using c-Fos expression as a marker for neuronal activation. We found that, upon pup exposure, the brain regions along the vomeronasal neural pathway, which mediates signal transduction, coding, and processing of pheromonal information, were more strongly activated in sexually-naïve male mice than those in father’s. Surgical ablation of the vomeronasal organ resulted in abrogation of the aggressive behaviors toward pups in sexually-naïve male mice and further led to expression of parental behaviors in half of them. These results suggest that the chemical cues inducing aggressive behaviors toward pups are received by