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A role of short-term synaptic plasticity in extracting velocity information of target in echolocating bats
e152
Abstracts / Neuroscience Research 71S (2011) e108–e415
fiber connections of the caudal mesopallium (MC) of pigeons by a tracttracing method. Injection of CTB was placed at A6.75. CTB-labeled neurons in MC were numerously distributed and the labeling extended rostrally and continuously into the intermediate mesopallium. In the caudal nidopallium, heavy labeling was seen in Field L complex. L1 contained many labeled neurons throughout its whole length. Labeled neurons were found in L3, but were less numerous than those in L1. Especially at levels of caudal L2, labeled neurons in L3 concentrated in a dorsal region and the labeling extended into a lateral portion of dorsal L2. Rostral and middle L2 contained a small number of labeled neurons. L1 labeling extended ventrally to an unnamed region situated between the ventral pole of L2 and the lateral ventricle and continued dorsolatelrally to L3. Injection of BDA was placed at A6.75. BDA-labeled fibers were densely distributed in MC between A7.75 and A6.50, with the labeling gradually reducing rostrally in the medial part of the intermediate mesopallium until A10.00. The main pathway from MC was found to run to the caudal nidopallium in a ventro-latero-caudal direction and reached the caudal pole of the medial part of the caudal nidopallium. MC is suggested to plays a feedback role of higher order auditory information. Research fund: 21580360. doi:10.1016/j.neures.2011.07.654
P2-j11 Distribution of glutamatergic, GABAergic, and glycinergic neurons in the auditory brainstem of Japanese macaque (Macaca fuscata) Tetsufumi Ito 1 , Masahiko Takada 2 1 2
Dep. Anatomy, Faculty of Medical Sciences, Univ of Fukui, Eiheiji, Japan Primate Research Institute, Kyoto Univ, Kyoto, Japan
It is known that cytoarchitecture of some auditory nuclei, especially superior olivary complex (SOC), of primates is very different from rodents. Indeed, there are some debates about correlating some subnuclei of primate with rodent equivalents. Since function of a nucleus is closely related to neurotranmitter expression, not only the cytoarchitecture but also expression of neurotransmitters will help for the identification of the nucleus. We recently found that expression pattern of glutamatergic and inhibitory amino acidergic (i.e. GABAergic and glycinergic) neurons is useful for identifying auditory nuclei of rats and mice (Ito et al., 2011). In this study, distribution of glutamatergic, GABAergic, and glycinergic neurons of the auditory brainstem of Japanese monkey (Macaca fuscata) is revealed by in situ hybridization for vesicular glutamate transporters (VGLUT), GAD67, and GLYT2, respectively. In general, pattern of neurotransmitter expression is very similar with some minor differences. VGLUT1 expression is restricted in the cochlear nuclei complex (CNC). Therefore, majority of glutamatergic neurons expresses only VGLUT2. In the ventral nucleus of the lateral lemniscus, SOC, and CNC, both glycinergic and GABAergic neurons are found. In the dorsal nucleus of the lateral lemniscus, inferior colliculus, and medial geniculate body, no glycinergic cell is found. The results demonstrate that expression pattern of excitatory and inhibitory amino acids helps the identification of auditory nuclei of primate as well as rodents. Research fund: KAKENHI 22700365. doi:10.1016/j.neures.2011.07.655
P2-j12 A role of short-term synaptic plasticity in extracting velocity information of target in echolocating bats Yoshitaka Mutoh 1 , Yoshiki Kashimori 1,2 , Yoshihiro Nagase 2 1 Department of Engeneering Science, University of ElectroCommunications, Chofu, Tokyo, Japan 2 Graduate School of Information Systems, University of Electro-Communications, Chofu, Tokyo, Japan
Most species of bat making echolocation use Doppler-shifted frequency of ultrasonic echo pulse to measure the velocity of target. To perform the fine-frequency analysis, the feedback signals from cortex to subcortical and peripheral areas are needed. The feedback signals are known to modulate the tuning property of subcortical neurons. Recent study has shown on an intriguing property of feedback signals that the electric stimulation of cortical neurons evokes the best frequency (BF) shifts of subcortical neurons away from the BF of the stimulated cortical neuron (centrifugal BF shift) and bucuculine (an antagonist of inhibitory GABA receptors) applied to the stimulation site changes the centrifugal BF shifts into the BF shifts towards the BF of stimulated cortical neurons (centripetal BF shift). Although these BF shifts are generated by the feedback signals from cortical neurons to subcortical neurons, it is not yet clear how the feedback signals determine the direction of BF shift. To address this issue, we present a neural model for detecting Doppler-shifted frequency of echo sound reflecting from a target. The model
consists of cochlea (Ch), inferior colliculus (IC), and Doppler-shifted constant frequency (DSCF) area, each of which is a linear array of frequency-tuned neurons. The three layers construct a tonotopical map, in which the neurons in each layer are tuned in to specific echo frequency ranging from 60.0 to 63.0 kHz, corresponding to the frequency range of the second harmonics. The neurons in different layers are connected with an excitatory and inhibitory synapse, whose weights are updated with learning with short-term dynamics. We show here that the receptive field of cortical neurons is modulated by short-term synaptic plasticity, depending on the stimulus context. This indicates that the tuning properties of subcortical neurons change on-line. We also propose a functional role of synaptic plasticity in detecting a moving target. doi:10.1016/j.neures.2011.07.656
P2-j13 Functional imaging of neuronal activity for odor avoidance of the nematode C. elegans Yosuke Miyanishi 1 , Junichi Nakai 2 , Kotaro Kimura 1 1 2
Dept. of Biological Sciences, Grad. Sch. of Science, Osaka Univ., Osaka, Japan Saitama University Brain Science Institute, Saitama, Japan
To better understand the neural basis that regulates sensory behavior and its modulation by learning, we are studying avoidance behavioral responses of C. elegans to repulsive odor 2-nonanone. We previously reported that the avoidance behavior to 2-nonanone is enhanced, rather than reduced, after preexposure to the odor, and this enhancement is acquired as a nonassociative dopamine-dependent learning (Kimura et al., J. Neurosci., 2010). In addition, we observed that worms respond to a spatial gradient of 2nonanone (Yamazoe and Kimura, in preparation), which cannot be simply explained by the pirouette or weathervane strategies. 2-nonanone is mainly sensed by the AWB neurons, which have been shown to exhibit odor-OFF response in aqueous step stimulation with 2-nonanone (Troemel et al., Cell, 1997; Ha et al., Neuron, 2010). To understand how the neuronal circuits of worms regulate the characteristic 2-nonanone behavioral response, we are monitoring calcium changes in the AWB and downstream neurons using G-CaMP 4 (Shindo et al., PLoS ONE, 2010). We thank Drs. S. Oda, K. Yoshida, and Y. Iino (U. Tokyo) for suggestions on microfluidics; M. Hendricks and Y. Zhang (Harvard) for aqueous 2-nonanone stimulation; and E. Busch and M. de Bono (MRC) for gaseous microfluidic stimulation. doi:10.1016/j.neures.2011.07.657
P2-j14 Sensory interaction between odorants diacetyl and nonanone in the nematode Caenorhabditis elegans Tetsuya Matsuura , Junichi Izumi, Mamoru Hioki, Hiroki Nagaya, Yasuaki Kobayashi, Mitsuyuki Ichinose Dept. of Welfare Eng., Fac. of Eng., Iwate Univ., Morioka, Japan The nematode Caenorhabditis elegans demonstrates chemotactic response to various chemicals. The chemicals are detected by chemosensory neurons in the head sensory organ amphid and the tail organ phasmid, and play a significant role in mediating chemotactic behavior. For example, odorant diacetyl is sensed by AWA neurons and is elicited an attractive response. Nonanone is detected by AWB neurons and is elicited an avoidance response. In the present study, we found a possibility that the nematodes have a sensory interaction between attractant diacetyl and repellent nonanone. Under the presence of food condition, the chemotactic response to 0.01% diacetyl of nematodes, which were pre-exposed to 0.1% diacetyl, was greater than that of non-exposed naive nematodes (p < 0.05). The response to diacetyl of nematodes, which were pre-exposed to 10% nonanone with food, was almost the same as that of naive nematodes in spite of decline in motor activity. These results suggest that the pre-exposure to diacetyl or nonanone causes a diacetyl-food associative learning in the nematodes. In the absence of food condition, the response to diacetyl of nematodes, which were preexposed to diacetyl or nonanone, was significantly smaller than that of non-exposed control nematodes, indicating that the nematodes showed a diacetyl adaptation after pre-exposure to diacetyl or nonanone. On the other hand, the chemotactic response to 10% nonanone of nematodes, which were pre-exposed to each odorant with food or without food, was decreased in comparison with that of non-exposed nematodes (p < 0.05). The nematodes may show a nonanone adaptation after pre-exposure to diacetyl or nonanone. To clarify this mechanism, we investigated the chemotactic response to diacetyl or nonanone using some mutants, which showed a defect in sensitivity of diacetyl or nonanone. The results using the mutants
Abstracts / Neuroscience Research 71S (2011) e108–e415
fiber connections of the caudal mesopallium (MC) of pigeons by a tracttracing method. Injection of CTB was placed at A6.75. CTB-labeled neurons in MC were numerously distributed and the labeling extended rostrally and continuously into the intermediate mesopallium. In the caudal nidopallium, heavy labeling was seen in Field L complex. L1 contained many labeled neurons throughout its whole length. Labeled neurons were found in L3, but were less numerous than those in L1. Especially at levels of caudal L2, labeled neurons in L3 concentrated in a dorsal region and the labeling extended into a lateral portion of dorsal L2. Rostral and middle L2 contained a small number of labeled neurons. L1 labeling extended ventrally to an unnamed region situated between the ventral pole of L2 and the lateral ventricle and continued dorsolatelrally to L3. Injection of BDA was placed at A6.75. BDA-labeled fibers were densely distributed in MC between A7.75 and A6.50, with the labeling gradually reducing rostrally in the medial part of the intermediate mesopallium until A10.00. The main pathway from MC was found to run to the caudal nidopallium in a ventro-latero-caudal direction and reached the caudal pole of the medial part of the caudal nidopallium. MC is suggested to plays a feedback role of higher order auditory information. Research fund: 21580360. doi:10.1016/j.neures.2011.07.654
P2-j11 Distribution of glutamatergic, GABAergic, and glycinergic neurons in the auditory brainstem of Japanese macaque (Macaca fuscata) Tetsufumi Ito 1 , Masahiko Takada 2 1 2
Dep. Anatomy, Faculty of Medical Sciences, Univ of Fukui, Eiheiji, Japan Primate Research Institute, Kyoto Univ, Kyoto, Japan
It is known that cytoarchitecture of some auditory nuclei, especially superior olivary complex (SOC), of primates is very different from rodents. Indeed, there are some debates about correlating some subnuclei of primate with rodent equivalents. Since function of a nucleus is closely related to neurotranmitter expression, not only the cytoarchitecture but also expression of neurotransmitters will help for the identification of the nucleus. We recently found that expression pattern of glutamatergic and inhibitory amino acidergic (i.e. GABAergic and glycinergic) neurons is useful for identifying auditory nuclei of rats and mice (Ito et al., 2011). In this study, distribution of glutamatergic, GABAergic, and glycinergic neurons of the auditory brainstem of Japanese monkey (Macaca fuscata) is revealed by in situ hybridization for vesicular glutamate transporters (VGLUT), GAD67, and GLYT2, respectively. In general, pattern of neurotransmitter expression is very similar with some minor differences. VGLUT1 expression is restricted in the cochlear nuclei complex (CNC). Therefore, majority of glutamatergic neurons expresses only VGLUT2. In the ventral nucleus of the lateral lemniscus, SOC, and CNC, both glycinergic and GABAergic neurons are found. In the dorsal nucleus of the lateral lemniscus, inferior colliculus, and medial geniculate body, no glycinergic cell is found. The results demonstrate that expression pattern of excitatory and inhibitory amino acids helps the identification of auditory nuclei of primate as well as rodents. Research fund: KAKENHI 22700365. doi:10.1016/j.neures.2011.07.655
P2-j12 A role of short-term synaptic plasticity in extracting velocity information of target in echolocating bats Yoshitaka Mutoh 1 , Yoshiki Kashimori 1,2 , Yoshihiro Nagase 2 1 Department of Engeneering Science, University of ElectroCommunications, Chofu, Tokyo, Japan 2 Graduate School of Information Systems, University of Electro-Communications, Chofu, Tokyo, Japan
Most species of bat making echolocation use Doppler-shifted frequency of ultrasonic echo pulse to measure the velocity of target. To perform the fine-frequency analysis, the feedback signals from cortex to subcortical and peripheral areas are needed. The feedback signals are known to modulate the tuning property of subcortical neurons. Recent study has shown on an intriguing property of feedback signals that the electric stimulation of cortical neurons evokes the best frequency (BF) shifts of subcortical neurons away from the BF of the stimulated cortical neuron (centrifugal BF shift) and bucuculine (an antagonist of inhibitory GABA receptors) applied to the stimulation site changes the centrifugal BF shifts into the BF shifts towards the BF of stimulated cortical neurons (centripetal BF shift). Although these BF shifts are generated by the feedback signals from cortical neurons to subcortical neurons, it is not yet clear how the feedback signals determine the direction of BF shift. To address this issue, we present a neural model for detecting Doppler-shifted frequency of echo sound reflecting from a target. The model
consists of cochlea (Ch), inferior colliculus (IC), and Doppler-shifted constant frequency (DSCF) area, each of which is a linear array of frequency-tuned neurons. The three layers construct a tonotopical map, in which the neurons in each layer are tuned in to specific echo frequency ranging from 60.0 to 63.0 kHz, corresponding to the frequency range of the second harmonics. The neurons in different layers are connected with an excitatory and inhibitory synapse, whose weights are updated with learning with short-term dynamics. We show here that the receptive field of cortical neurons is modulated by short-term synaptic plasticity, depending on the stimulus context. This indicates that the tuning properties of subcortical neurons change on-line. We also propose a functional role of synaptic plasticity in detecting a moving target. doi:10.1016/j.neures.2011.07.656
P2-j13 Functional imaging of neuronal activity for odor avoidance of the nematode C. elegans Yosuke Miyanishi 1 , Junichi Nakai 2 , Kotaro Kimura 1 1 2
Dept. of Biological Sciences, Grad. Sch. of Science, Osaka Univ., Osaka, Japan Saitama University Brain Science Institute, Saitama, Japan
To better understand the neural basis that regulates sensory behavior and its modulation by learning, we are studying avoidance behavioral responses of C. elegans to repulsive odor 2-nonanone. We previously reported that the avoidance behavior to 2-nonanone is enhanced, rather than reduced, after preexposure to the odor, and this enhancement is acquired as a nonassociative dopamine-dependent learning (Kimura et al., J. Neurosci., 2010). In addition, we observed that worms respond to a spatial gradient of 2nonanone (Yamazoe and Kimura, in preparation), which cannot be simply explained by the pirouette or weathervane strategies. 2-nonanone is mainly sensed by the AWB neurons, which have been shown to exhibit odor-OFF response in aqueous step stimulation with 2-nonanone (Troemel et al., Cell, 1997; Ha et al., Neuron, 2010). To understand how the neuronal circuits of worms regulate the characteristic 2-nonanone behavioral response, we are monitoring calcium changes in the AWB and downstream neurons using G-CaMP 4 (Shindo et al., PLoS ONE, 2010). We thank Drs. S. Oda, K. Yoshida, and Y. Iino (U. Tokyo) for suggestions on microfluidics; M. Hendricks and Y. Zhang (Harvard) for aqueous 2-nonanone stimulation; and E. Busch and M. de Bono (MRC) for gaseous microfluidic stimulation. doi:10.1016/j.neures.2011.07.657
P2-j14 Sensory interaction between odorants diacetyl and nonanone in the nematode Caenorhabditis elegans Tetsuya Matsuura , Junichi Izumi, Mamoru Hioki, Hiroki Nagaya, Yasuaki Kobayashi, Mitsuyuki Ichinose Dept. of Welfare Eng., Fac. of Eng., Iwate Univ., Morioka, Japan The nematode Caenorhabditis elegans demonstrates chemotactic response to various chemicals. The chemicals are detected by chemosensory neurons in the head sensory organ amphid and the tail organ phasmid, and play a significant role in mediating chemotactic behavior. For example, odorant diacetyl is sensed by AWA neurons and is elicited an attractive response. Nonanone is detected by AWB neurons and is elicited an avoidance response. In the present study, we found a possibility that the nematodes have a sensory interaction between attractant diacetyl and repellent nonanone. Under the presence of food condition, the chemotactic response to 0.01% diacetyl of nematodes, which were pre-exposed to 0.1% diacetyl, was greater than that of non-exposed naive nematodes (p < 0.05). The response to diacetyl of nematodes, which were pre-exposed to 10% nonanone with food, was almost the same as that of naive nematodes in spite of decline in motor activity. These results suggest that the pre-exposure to diacetyl or nonanone causes a diacetyl-food associative learning in the nematodes. In the absence of food condition, the response to diacetyl of nematodes, which were preexposed to diacetyl or nonanone, was significantly smaller than that of non-exposed control nematodes, indicating that the nematodes showed a diacetyl adaptation after pre-exposure to diacetyl or nonanone. On the other hand, the chemotactic response to 10% nonanone of nematodes, which were pre-exposed to each odorant with food or without food, was decreased in comparison with that of non-exposed nematodes (p < 0.05). The nematodes may show a nonanone adaptation after pre-exposure to diacetyl or nonanone. To clarify this mechanism, we investigated the chemotactic response to diacetyl or nonanone using some mutants, which showed a defect in sensitivity of diacetyl or nonanone. The results using the mutants