自律神経系 Autonomic Nervous System
P1-1-158 Withdrawn	P1-1-159 音のテンポと呼吸数の組み合わせが自律神経系に与える影響II：心拍変動解析 The effects of the combination of acoustic tempo and respiratory rate on the autonomic nervous system II : heart rate variability ○渡辺謙1, 大石悠貴2, 柏野牧夫1,2,3 ○Ken Watanabe1, Yuuki Ooishi2, Makio Kashino1,2,3 東工大院・総合理工・物情1, NTTコミュニケーション科学基礎研究所2 Dept Info Process, Tokyo Inst of Tech, Tokyo1, NTT Communication Science Laboratories, Kanagawa2, JST CREST, Japan3 Many studies have investigated the effects of music on human activity and revealed the influences of music on the autonomic nervous system (ANS) and respiration patterns.However, it is not clear what effect is induced by different individual musical parameters. In this study, we focused on one of the musical parameters, namely tempo, and investigated the effects of the relationship between acoustic tempo and respiratory rate on the ANS. Thirty six healthy people aged 20-35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome displayed on a screen, and in each five-minute session they listened to simple drum sounds each of which had a constant tempo. We varied the respiratory rate - acoustic tempo combination. The respiratory rate was controlled at 15, 20 cycles per minute (CPM) and the acoustic tempo was 60, 80 beats per minute (BPM) or silent environment. Electrocardiograms (ECGs) and an elastic chest band were used to measure the heart rate and respiratory rate, respectively, throughout the experiments. The mean heart rate and heart rate variability (HRV) were calculated from the ECGs as indices of ANS activity.We observed a significant increase in the mean heart rate and the ratio of the low-frequency component (0.04-0.15 Hz) to the high-frequency component (0.15-0.40 Hz) of HRV, only when the combination of the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the combination of respiratory rate and acoustic tempo is important for the effects of music on the sympathetic tone.
P1-1-160 新生ラット摘出脳幹―脊髄標本においてcapsaicinが呼吸リズムに及ぼす影響 Effects of capsaicin on the respiratory rhythm in brainstem-spinal cord preparations from the newborn rats ○谷まりほ1, 鬼丸洋1 ○Mariho Tani1, Hiroshi Onimaru1 昭和大学大学院　医学研究科　第二生理学1 Department of Physiology, Showa University School of Medicine, Hatanodai, Tokyo, Japan1 Capsaicin is an agonist for heat-sensitive transient receptor potential vanilloid 1(TRPV1) channel and stimulates pain nerve terminals to cause intense burning sensation.We examined the effects of capsaicin on respiratory rhythm generation in the brainstem-spinal cord preparations isolated from 0-3 day old Wistar rats. Preparations were superfused at a rate of 3.0 ml/min with the following artificial cerebrospinal fluid (in mM): 124 NaCl, 5.0 KCl, 1.24 KH2PO4, 2.4 CaCl2, 1.3 MgCl2, 26 NaHCO3 and 30 glucose, equilibrated with 95% O2 and 5% CO2, pH 7.4, at 26-27%deg;C. Inspiratory activity was monitored from the fourth cervical ventral root. Bath application of capsaicin induced biphasic responses in the respiratory rate; initial decrease and subsequent increase. The inhibitory and excitatory effects were dose-dependent (1-10 µM). Effects of capsaicin were partially reversed by TRPV1 antagonist, capsazepine (10 µM). These effects of capsaicin were strongly desensitized to the repeated application. This desensitization was observed even after treatment with calmodulin antagonist, W-7(50 µM) or in the low Ca2+ /high Mg2+ solution with 0.5 mM EGTA. Pre-inspiratory (Pre-I) neurons were depolarized in 2 min after capsaicin application and partially recovered after washed out. We confirmed immunoreactivity of TRPV1 channel protein on parafacial neurons including cells expressing a transcription factor, Phox2b. Although capsaicin depolarized CO2 sensitive Pre-I neurons in the presence of TTX, the response was not enough to engage for membrane depolarization by hypercapnic stimulation (2% -> 8%). Our findings suggest that activation of TRPV1 channels in the medulla had the various influences on the respiratory center. The desensitization of capsaicin effects in the respiratory center might be produced by calcium-independent mechanisms. Furthermore, our results suggested that TRPV1 channels are less involved in CO2 sensitivity of Phox2b-expressing Pre-I neurons.	P1-1-161 結合腕傍核へ投射する孤束核ニューロンは高炭酸ガス負荷によって活性化される Parabrachial nucleus-projecting neurons in the nucleus of the solitary tract are activated by hypercapnia in the mouse ○横田茂文1, 安井幸彦1 ○Shigefumi Yokota1, Satvinder Kaur2, Veronique G.J.M. Vanderhorst2, Clifford B. Saper2, Yukihiko Yasui1, Nancy L. Chamberlin2 島根大学医学部解剖学講座神経形態学1, ベスイスラエル・デアコネス病院・ハーバード医学校、神経学2 Dept. of Anat. & Morphol. Neurosci., Shimane Univ. Sch. of Med., Izumo, Japan1, Dept. of Neurol., Beth Israel Deaconess Med. Ctr and Harvard Med. Sch., Boston, USA2 Elevated CO2 (hypercapnia) facilitates breathing by increasing the depth and frequency of ventilation. However, the neural mechanisms underlying these effects are not completely understood. It is suggested that the nucleus of the solitary tract (NST) receives arterial PCO2 information not only from the carotid body but also from the retrotrapezoid nucleus, and the parabrachial nucleus (PBN) is a key mediator of respiratory facilitation in the hypercapnia. In the present study, we examine the distribution of NST neurons activated by hypercapnia by using Fos-labeling, and then examine whether or not PBN-projecting NST neurons are activated by hypercapnia by using retrograde tracing combined with Fos-labeling. In the results, 1) after 2 hours exposure to normoxic hypercapnia (10% CO2), the number of Fos-positive neurons in the caudal NST was increased compared to the control condition, 2) using in situ hybridization combined with Fos-labeling, we demonstrated that the Fos-positive neurons in the medial NST showed vesicular glutamate transporter 2 (VGLUT2) mRNA and those in the lateral NST showed vesicular GABA transporter (VGAT) mRNA, 3) after cholera toxin B subunit (CTb) injection into the lateral PBN, some CTb-labeled neurons in the commissural, medial, and ventrolateral NST subnuclei showed Fos-immunoreactivity, 4) using a combined retrograde tracing and in situ hybridization, we further demonstrated that most of the CTb-labeled medial NST neurons and some of the CTb-labeled ventrolateral NST neurons were positive for VGLUT2 mRNA and VGAT mRNA, respectively after CTb injection into the PBN. These excitatory and inhibitory NST-PBN projections may have an important role for the control of respiration during hypercapnia.
P1-1-162 DMSOによる痛覚・呼吸機能の抑制 DMSO: A potential detriment for nociception and respiration ○武田湖太郎1, , 小山田吉孝3, 岡田泰昌1 ○Kotaro Takeda1, Mieczyslaw Pokorski1,2, Yoshitaka Oyamada3, Yasumasa Okada1 国立病院機構村山医療センター 臨床研究センター1, 国立病院機構東京医療センター 呼吸器科3 Clinical Research Center, National Hospital Organization Murayama Medical Center, Musashimurayama, Japan1, Department of Respiratory Research, Medical Research Center, Polish Academy of Sciences, Warsaw, Poland2, Department of Respiratory Medicine, National Hospital Organization Tokyo Medical Center, Tokyo, Japan3 Dimethyl sulfoxide (DMSO) is one of the most versatile substances among organosulfur compounds. Since its toxicity is much smaller (i.e., the LD50 dose is higher) than those ethanol, acetone, and other common solvents, DMSO is widely used as a solvent in pharmacological animal experiments. Nevertheless, there are reports of DMSO's suppressive actions on sensory perception and neural function. In the present study, therefore, we examined the dose-dependent effects of DMSO (intraperitoneally injected cumulative doses of 0.5, 1.5, 3.5, 7.5, and 15.5 g/kg at 50 minutes intervals) on nociception and on respiratory control in the unrestrained adult mice. We performed the hot-plate test at 55ºC to assess acute pain sensitivity to thermal stimulation. The response latency of front-paw licking, hind-paw licking, standing, and jumping were measured before and after each DMSO dose condition. The respiratory flow was measured by whole body plethysmography during room air and hypoxic conditions (inspired O2 concentration 7%). Tidal volume, breathing frequency, and instantaneous minute ventilation were calculated from the flow data, and were compared among each DMSO dose condition. For nociception, low DMSO doses (0.5 and 1.5 g/kg) did not affect the response latency to thermal stimulation, but the highest dose (15.5 g/kg) prolonged it. For respiratory function, the respiratory parameters, especially tidal volume and instantaneous minute ventilation, were inhibited at higher DMSO doses (7.5 and 15.5 g/kg). Hypoxic ventilatory augmentation was also suppressed at these high doses of DMSO. We conclude that DMSO at the cumulative dose higher than 3.5 g/kg could suppress sensory neural functions. Therefore, caution should be exercised when DMSO is used as a solvent in pharmacological experiments of pain or respiration.	P1-1-163 ラットの睡眠活動時における海馬CA1神経活動と腎および腰部交感神経活動の周波数依存性カップリング Frequency coupling between hippocampal CA1 neuronal activity and renal and lumbar sympathetic nerve activity during sleep-wake cycle in rats ○森本祐加1, 吉本光佐2, 朝倉枝里子1, 松浦文奈1, 三木健寿1 ○Yuka Morimoto1, Misa Yoshimoto2, Eriko Asakura1, Ayana Matsuura1, Kenju Miki1 奈良女子大学　生活環境学部　統御生理学 三木研究室1, 国立循環器病センター研究所2 Dep of Integr Physiol, Nara Women's Univ, Nara1, Dept of Cardiac Physiol, NCVC, Osaka2 The hippocampus is critically involved in emotional information processing. Emotional enhancement activates sympathetic outflows, causing changes in cardiovascular functions. Thus, there has been thought some informational links between hippocampus neural activity and sympathetic outflows. However, little is known about relationships between hippocampus neuronal and sympathetic nerve activity under normal physiological states. In the present study hippocampal CA1 neuronal activity and renal (RSNA) and lumbar sympathetic nerve activity (LSNA) were measured simultaneously and continuously in freely moving rats, and we studied the relationships among hippocampal CA1 neuronal activity and RSNA and LSNA. Wistar male rats were instrumented chronically with multiple electrodes for hippocampal CA1 neuronal activity and bipolar electrode for RSNA, LSNA and electroencephalogram. Power spectral density (PSD) and coherence of these neural activities during NREM sleep, REM sleep, moving, grooming, eating and drinking states were determined. The PSD of CA1 neuronal activity showed a peak centered at approximately 0.1 Hz. The PSD of RSNA and LSNA had four peaks that were centered at approximately 0.1 Hz, 0.5 Hz, 1.5 Hz and 7.5 Hz. The peaks PSD of RSNA and LSNA around 1.5 Hz and 7.5 Hz may be correlated with respiratory and cardiac cycle, respectively. There was a weak but significant coherence at ~0.1 Hz between CA1 neural activity and LSNA and RSNA. These data suggest that informational link between hippocampus neuronal activity and sympathetic nerve activity around may exist at a very low frequency band around ~0.1 Hz.
P1-1-164 マウス舌下神経核における呼吸性リズム発火の発達変化 Developmental changes in the respiration-related rhythmic activity in mouse hypoglossal nucleus ○岡部明仁1, 荒田晶子2, 清水-岡部千草1, 小西史朗3, 福田敦夫4, 高山千利1 ○Akihito Okabe1, Akiko Arata2, Chigusa Shimizu-Okabe1, Shiro Konishi3, Atsuo Fukuda4, Chitoshi Takayama1 琉球大院・医・分子解剖1, 兵庫医大・生理2, 徳島文理大・香川薬・薬理3, 浜松医大・医・神経生理4 Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, Nishihara1, Department of Physiology, Hyogo College of Medicine, Nishinomiya2, Faculty of Pharmaceutical Science at Kagawa, Tokushima Bunri University, Shido3, Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu4 The role of GABAergic neurotransmission associated with respiration-related rhythmic activity (RRA) has been still under discussion in the medulla at neonatal stage. The property of GABAergic action likely depends on the concentration of intracellular chloride ions ([Cl-]i) determined by the balance of KCC2 (K+-Cl- cotransporter-extrusion system) and NKCC1 (Na+, K+-2Cl- cotransporter-accumulation system). Here, we examined how the Cl- cotransporters contribute to the RRA during development in the hypoglossal motor nucleus where inspiratory neurons reside. We recorded the RRA extracellulary in 700 μm-thick-medullary slice preparation obtained from postnatal day (P) 0-7 mice. Soaking slices with 8 mM-K+-containing artificial cerebrospinal fluid (ACSF) induced the RRA. Under these conditions, application of 100 μM GABA significantly increased the frequency of RRA after P3. On the other hand, a KCC2 blocker (50 μM DIOA) caused a significant decrease of the RRA frequency in P5-7 slices. However, a NKCC1 blocker (10 μM bumetanide) did not cause any changes in the RRA frequency during the first week after birth. In addition, the immunoreactivity of KCC2 was detected in the hypoglossal nucleus at the stage from P0 to P7. These results suggested that the effects of KCC2 increased and did not change NKCC1 during first week. It seemed that the GABA receptors on the inhibitory neurons with KCC2 might exist in the hypoglossal nucleus and that would be the key player to maintain the RRA frequency in a week after birth.	P1-1-165 除皮質ラット灌流標本では吸気相と同期して下顎の開口運動が起こる Lower jaw movements generated in the inspiratory phase in a decerebrate and arterially perfused in situ rat preparation ○中山希世美1, 横松充2, 望月文子1, 井上富雄1, 矢澤格3 ○Kiyomi Nakayama1, Mitsuru Yokomatsu2, Ayako Mochizuki1, Tomio Inoue1, Itaru Yazawa3 昭和大・歯・口腔生理1, 昭和大・歯・小児成育歯科2, 昭和大・医・第一解剖3 Dept. of Oral Physiology, Showa Univ. School of Dent., Tokyo, Japan1, Dept. of Pediatric Dentistry, Showa Univ. School of Dent., Tokyo, Japan2, Dept. of Anatomy, Showa Univ. School of Med., Tokyo, Japan3 The relevance of the studies to the neural mechanisms of adult breathing, chewing and swallowing is unclear, because the neonatal brainstem-spinal cord (P0-2 days) is immature and most studies have been performed before the primitive reflexes disappear. To overcome these difficulties in the rat, we have adapted a decerebrate, artificially-perfused in situ preparation first developed by Pickering et al., (J. Neurosci. Meth. 2006). Using electrophysiological techniques in a decerebrate and arterially perfused in situ rat preparation (P9-24 days), extracellular recordings were performed to investigate the interplay of neural discharge patterns involved in respiration and lower jaw movements in response to various perfusion flow rates. Respiratory discharge was recorded from the phrenic nerve and respiratory-related discharges were obtained from the trigeminal, facial and hypoglossal nerves. Body temperature was set at room temperature. The frequencies of neuronal discharges from all the four nerves increased with increases in the flow rates. When the flow rate was set at about 6× the total blood volume per minute, the phrenic discharge showed "eupneaic pattern" and "regular rhythm". As the flow rate futher increased, the preparation was exposed to a hyperoxic/normocapnic state and all nerve discharges became clearly organized into episodes of greater frequency and duration, punctuated by periods of quiescence. All respiratory-related discharges synchronized to the phrenic discharge at all flow rates we tested. Experiments are currently in progress to establish the utility of this preparation for studies of adult trigeminal respiratory motor behavior generated by the mature brainstem-spinal cord.
P1-1-166 新生ラットin vitro標本及び幼若ラットin situ標本の呼吸リズム形成におけるNa/K APTaseの重要性 Significance of Na/K ATPase on respiratory rhythm generation in the new born rat in vitro- and in the juvenile rat in situ- preparations ○鬼丸洋1, 津澤佳代1, 谷まりほ1, 矢澤格2 ○Hiroshi Onimaru1, Kayo Tsuzawa1, Mariho Tani1, Itaru Yazawa2 昭和大学医学部第二生理1, 昭和大学医学部解剖学教室2 Dept Physiol, Showa Univ School of Med, Tokyo1, Dept Anat, Showa Univ School of Med, Tokyo2 Significance of Na/K ATPase on respiratory rhythm generation is not well understood. We studied effects of a Na/K ATPase blocker, ouabain on respiratory rhythm. Experiments were performed with brainstem-spinal cord preparations from 0-3 day old Wistar rats. Some experiments were performed with the in situ perfused- preparation from juvenile rat (P11-13). Newborn rat preparations were superfused at a rate of 3.0 ml/min with the following artificial cerebrospinal fluid (in mM): 124 NaCl, 5.0 KCl, 1.24 KH2PO4, 2.4 CaCl2, 1.3 MgCl2, 26 NaHCO3 and 30 glucose, equilibrated with 95% O2 and 5% CO2, pH 7.4, at 26-27oC. Inspiratory activity was monitored from the fourth cervical ventral root (C4). Application of ouabain (15-20 min) increased dose-dependently the burst rate of C4 inspiratory activity. After washed out, the burst rate further increased to reach a quasi maximum values under each condition; 137% of control in 2 μM, 203% in 10 μM, 297% in 40 μM at 30 min after washed out. Inspiratory or pre-inspiratory neurons in the rostral ventrolateral medulla depolarized. We also examined effects of lowering K+ concentration (final concentration of 1.24 mM) on C4 burst rate and membrane potentials. This caused initial decrease of C4 burst rate (74% of control) and subsequent increase (111% of control). Respiratory neurons initially hyperpolarized in response to lowering K+ concentration, then tended to depolarize. We have obtained similar results (i.e. increase in rate of the phrenic burst) in the in situ perfused- preparation from P11-13 rats. We concluded that Na/K ATPase activity is an important factor on respiratory rhythm regulation. K+ concentration in the superfusate could affect activity of Na/K ATPase and thus the respiratory rhythm.

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