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Neural responses of inferior colliculus to echolocation sounds in Japanese house bat (Pipistrellus abramus)
S100
Abstracts / Neuroscience Research 58S (2007) S1–S244
6 Neural responses of inferior colliculus to echolocation P1-f0
9 Effects of musical experience on the automatic auditory P1-f0
sounds in Japanese house bat (Pipistrellus abramus)
feature processing
Kazuhiro Goto 1 , Shizuko Hiryu 2 , Hiroshi Riquimaroux 1 1 Department of Knowledge and Engineering and Computer Sciences, Doshisha University, Kyotanabe, Japan; 2 Research Center for Intelligent Information Science, Doshisha University, Kyotanabe, Japan
Kentaro Ono 1 , Akinori Nakamura 1 , Kenji Yoshiyama 2 , Takeshi Kinkori 1 , Masahiko Bundo 3 , Kengo Ito 1 1 Department of Brain Sciences and Molecular Imaging, National Center for Geriatrics and Gerontology, Japan; 2 Department of Psychiatry, NCGG, Japan; 3 Department of Brainsurgery, NCGG, Japan
In our laboratory, we found compensation for intensity of the echo by recording the returning echoes from flying bats (Pipistrellus abramus) with telemetry microphones. This result suggested the existence of neural mechanisms that proved the echo-intensity compensation. A number of neurophysiological studies for intensities of pulse and echo were conducted, however, the echo intensity compensation had hardly investigated. In this study, we recorded the single unit responses of inferior colliculus (IC) in the awake bats to returning echoes presented under free field stimulation, and investigated the relationship between the results and echo-intensity compensation behavior.
7 Arc mRNA expression pattern in female zebra finch P1-f0 auditory pathway Akira Fujimura, Koji Hotta, Kotaro Oka Center for Biosciences and Informatics, Keio University, Kanagawa, Japan Male song discrimination mechanism in the female brain is an open question in the songbird study. To answer this question, we utilized the cellular compartment analysis of temporal activity by fluorescent in situ hybridisation (catFISH) for Arc mRNA. Arc is one of effector immediate early genes, and expression of Arc is synaptic-activity dependent. Arc mRNA is not translated at the cell bodies but transferred to the peripheral of the neurons and translated locally. Because this process is time-dependent, two populations of neurons that are activated at different timings can be discriminated with Arc mRNA expression by FISH. Two conspecific songs were applied sequentially with 50 min interval to the female zebra finch. Then, the expression of Arc was investigated. We found that caudal medial mesopallium and hippocampal formation are the candidates for song discrimination regions. In these regions, some neurons activated by two songs are overlapped. These findings provide the neural coding strategy of auditory pathway for song discrimination. Research funds: Grant-in-Aid for Scientific Research on Priority Areas No. 454
8 P2X1 in the inferior colliculus P1-f0 Kousuke Taki, Motoi Kudo Department of Anatomy, Shiga University of Medical Science, Otsu, Japan P2X receptors are ionotropic receptors activated by extracellular ATP. P2X receptors in the dorsal root ganglion are thought to be related to the nociception. P2X receptors are also reported to be distributed throughout the central nervous system. We explored P2X1 expression in the inferior colliculus (IC) which is known as brainstem auditory center by immunohistochemistry. P2X1 immunoreactive cells were found in the central and the external nucleus of the IC as large or medial sized multipolar cells. They seemed to disappear in the late developmental period: The IC of 8 weeks old rats had many positive cells, while the IC of 12 weeks old rats had no positive cells. We also found sparse but distinct P2X1 immunoreactive fibers in the central nucleus of the IC. They seemed to appear with late maturation between 8 week and 12 week. Double immunofluorecence study with tracer technique showed that these fibers were corticocollicular. These findings suggest that ATP from glial cells in the IC modulates auditory processing. Research fund: KAKENHI (17500228)
Music consists of different features of sound information. Although they are believed to be processed differently, its detailed brain mechanisms and effects of learning are still unclear. We studied the effects of musical training on preattentive discriminating processes of the sound features using auditory mismatch fields (MMFs), which are evoked by deviant sounds embedded in a repetitve standard sounds. During four different oddball tasks to detect the frequency, rhythm, chord and timbre information processing, MMFs were measured in eight musicians and nine nonmusicians using magnetoencephalography. Irrespective of the musical experience, MMF waveforms were different among the sound features. However, musicians generally showed the left hemispheric dominance, whereas nonmusicians showed the right dominance, especially in frequency and chord. These results suggest that the auditory feature processing is modulated by musical experience.
A rat model for investigating speech sound recognition P1-f10 in humans: Discrimination learning of synthetic speech sounds dependent on the presence of the auditory cortex Masaharu Kudoh, Masato Habuka, Ryuichi Hishida, Katsuei Shibuki Department of Neurophysiology, Brain Research Institute, Niigata University, Niigata, Japan The first and second formants of vowels are essential for vowel recognition. We have reported that discrimination learning between vowel-like sounds with multiple formants requires the presence of the auditory association cortex in rats. In the present study, we investigated discrimination learning of voiced stop consonants /b, d, g/, which are characterized by transition of multiple formants. Water-deprived rats were trained to discriminate between two synthesized stop consonants. Licking a spout during presentation of a consonant was rewarded with water while the other was not. Bilateral lesions of the auditory cortex impaired discrimination learning between stop consonants with multiple formant transitions, while discrimination between single formant transitions was not affected. These results suggest that discrimination learning between synthetic speech sounds in rats may serve as an animal model for investigating speech sound recognition in humans.
P1-f11 Functional connections between the core and belt fields of the guinea pig auditory cortex observed by optical imaging Junsei Horikawa, Ryota Numata, Daisuke Uchiyama, Shunji Sugimoto Department of Knowledge-Based Information Engineering, Toyohashi University of Technology, Toyohashi, Japan Functional connections between the core and belt fields of the guinea pig auditory cortex were investigated using voltage-sensitive-dye optical imaging and local cortical inhibition and activation by muscimol and bicuculline (GABAa agonist and antagonist, respectively). Inhibition of AI in the core fields by muscimol resulted in a decrease of responses to pure tones in the ventroanterior (VA), ventromedial (VM), ventroposterior (VP) and posterior (P) belt fields. Inhibition of the dorsocaudal field (DC) in the core fields resulted in a decrease of the response in VM, P and VP. Activation of AI by bicuculline induced an increase of the response in DC, VA and VM and a decrease of the response in P and VP. Activation of DC induced an increase of the response in VM, VP and P but no change in the response in AI and VA. These results suggest that AI and DC, respectively, send differential excitatory and inhibitory outputs to each belt fields of the auditory cortex.
Abstracts / Neuroscience Research 58S (2007) S1–S244
6 Neural responses of inferior colliculus to echolocation P1-f0
9 Effects of musical experience on the automatic auditory P1-f0
sounds in Japanese house bat (Pipistrellus abramus)
feature processing
Kazuhiro Goto 1 , Shizuko Hiryu 2 , Hiroshi Riquimaroux 1 1 Department of Knowledge and Engineering and Computer Sciences, Doshisha University, Kyotanabe, Japan; 2 Research Center for Intelligent Information Science, Doshisha University, Kyotanabe, Japan
Kentaro Ono 1 , Akinori Nakamura 1 , Kenji Yoshiyama 2 , Takeshi Kinkori 1 , Masahiko Bundo 3 , Kengo Ito 1 1 Department of Brain Sciences and Molecular Imaging, National Center for Geriatrics and Gerontology, Japan; 2 Department of Psychiatry, NCGG, Japan; 3 Department of Brainsurgery, NCGG, Japan
In our laboratory, we found compensation for intensity of the echo by recording the returning echoes from flying bats (Pipistrellus abramus) with telemetry microphones. This result suggested the existence of neural mechanisms that proved the echo-intensity compensation. A number of neurophysiological studies for intensities of pulse and echo were conducted, however, the echo intensity compensation had hardly investigated. In this study, we recorded the single unit responses of inferior colliculus (IC) in the awake bats to returning echoes presented under free field stimulation, and investigated the relationship between the results and echo-intensity compensation behavior.
7 Arc mRNA expression pattern in female zebra finch P1-f0 auditory pathway Akira Fujimura, Koji Hotta, Kotaro Oka Center for Biosciences and Informatics, Keio University, Kanagawa, Japan Male song discrimination mechanism in the female brain is an open question in the songbird study. To answer this question, we utilized the cellular compartment analysis of temporal activity by fluorescent in situ hybridisation (catFISH) for Arc mRNA. Arc is one of effector immediate early genes, and expression of Arc is synaptic-activity dependent. Arc mRNA is not translated at the cell bodies but transferred to the peripheral of the neurons and translated locally. Because this process is time-dependent, two populations of neurons that are activated at different timings can be discriminated with Arc mRNA expression by FISH. Two conspecific songs were applied sequentially with 50 min interval to the female zebra finch. Then, the expression of Arc was investigated. We found that caudal medial mesopallium and hippocampal formation are the candidates for song discrimination regions. In these regions, some neurons activated by two songs are overlapped. These findings provide the neural coding strategy of auditory pathway for song discrimination. Research funds: Grant-in-Aid for Scientific Research on Priority Areas No. 454
8 P2X1 in the inferior colliculus P1-f0 Kousuke Taki, Motoi Kudo Department of Anatomy, Shiga University of Medical Science, Otsu, Japan P2X receptors are ionotropic receptors activated by extracellular ATP. P2X receptors in the dorsal root ganglion are thought to be related to the nociception. P2X receptors are also reported to be distributed throughout the central nervous system. We explored P2X1 expression in the inferior colliculus (IC) which is known as brainstem auditory center by immunohistochemistry. P2X1 immunoreactive cells were found in the central and the external nucleus of the IC as large or medial sized multipolar cells. They seemed to disappear in the late developmental period: The IC of 8 weeks old rats had many positive cells, while the IC of 12 weeks old rats had no positive cells. We also found sparse but distinct P2X1 immunoreactive fibers in the central nucleus of the IC. They seemed to appear with late maturation between 8 week and 12 week. Double immunofluorecence study with tracer technique showed that these fibers were corticocollicular. These findings suggest that ATP from glial cells in the IC modulates auditory processing. Research fund: KAKENHI (17500228)
Music consists of different features of sound information. Although they are believed to be processed differently, its detailed brain mechanisms and effects of learning are still unclear. We studied the effects of musical training on preattentive discriminating processes of the sound features using auditory mismatch fields (MMFs), which are evoked by deviant sounds embedded in a repetitve standard sounds. During four different oddball tasks to detect the frequency, rhythm, chord and timbre information processing, MMFs were measured in eight musicians and nine nonmusicians using magnetoencephalography. Irrespective of the musical experience, MMF waveforms were different among the sound features. However, musicians generally showed the left hemispheric dominance, whereas nonmusicians showed the right dominance, especially in frequency and chord. These results suggest that the auditory feature processing is modulated by musical experience.
A rat model for investigating speech sound recognition P1-f10 in humans: Discrimination learning of synthetic speech sounds dependent on the presence of the auditory cortex Masaharu Kudoh, Masato Habuka, Ryuichi Hishida, Katsuei Shibuki Department of Neurophysiology, Brain Research Institute, Niigata University, Niigata, Japan The first and second formants of vowels are essential for vowel recognition. We have reported that discrimination learning between vowel-like sounds with multiple formants requires the presence of the auditory association cortex in rats. In the present study, we investigated discrimination learning of voiced stop consonants /b, d, g/, which are characterized by transition of multiple formants. Water-deprived rats were trained to discriminate between two synthesized stop consonants. Licking a spout during presentation of a consonant was rewarded with water while the other was not. Bilateral lesions of the auditory cortex impaired discrimination learning between stop consonants with multiple formant transitions, while discrimination between single formant transitions was not affected. These results suggest that discrimination learning between synthetic speech sounds in rats may serve as an animal model for investigating speech sound recognition in humans.
P1-f11 Functional connections between the core and belt fields of the guinea pig auditory cortex observed by optical imaging Junsei Horikawa, Ryota Numata, Daisuke Uchiyama, Shunji Sugimoto Department of Knowledge-Based Information Engineering, Toyohashi University of Technology, Toyohashi, Japan Functional connections between the core and belt fields of the guinea pig auditory cortex were investigated using voltage-sensitive-dye optical imaging and local cortical inhibition and activation by muscimol and bicuculline (GABAa agonist and antagonist, respectively). Inhibition of AI in the core fields by muscimol resulted in a decrease of responses to pure tones in the ventroanterior (VA), ventromedial (VM), ventroposterior (VP) and posterior (P) belt fields. Inhibition of the dorsocaudal field (DC) in the core fields resulted in a decrease of the response in VM, P and VP. Activation of AI by bicuculline induced an increase of the response in DC, VA and VM and a decrease of the response in P and VP. Activation of DC induced an increase of the response in VM, VP and P but no change in the response in AI and VA. These results suggest that AI and DC, respectively, send differential excitatory and inhibitory outputs to each belt fields of the auditory cortex.