Development of miniature implantable electrode and telemeter for long-term recording of sympathetic efferent nerve activity

开发用于长期记录交感传出神经活动的微型植入电极和遥测仪

• 批准号: 13557006
• 负责人: KANJI Matsukawa
• 金额: $ 7.17万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13557006/
• 关键词: Microelectrode; Sympathetic nerve activity; Long-term recording; Electro-conductive rubber; Implantable telemeter; Blood pressure regulation; Conscious animals; The autonomic nervous system

It is important for better understanding of sympathetic control of the cardiovascular system to measure sympathetic outflows to various vascular beds and analyze the long-term changes in sympathetic outflow following a given intervention. The aim of this study was to develop a new implantable microelectrode and a miniature telemetry device for stable and long-term recording of sympathetic neural discharges in freely moving small animals. We have made two types of the novel bipolar cuff electrodes with electro-conductive rubber or water-absorbent polymer, which can be applied to the renal nerve in the rat. When the microelectrodes were embedded in saline, electrical impedance of the electrodes was 2.8-9.4 kΩ in a frequency range of 0.05-3 kHz, which corresponded to the band of sympathetic discharge. Either electrode showed stable electrical impedance over several weeks, suggesting that the impedance was low enough to record sympathetic nerve activity with low background noise as long as … More the electrode had good contact with a nerve bundle. Because the present electrodes were of small size (volume, 2mm^3) and handled easily, it took a shorter time to implant each electrode on the nerve without any nerve injury due to drying or mechanical damage and the electrodes worked well as long as being used in the acute type of experiments. Therefore the novel electrodes may be useful for recording of sympathetic nerve discharge in conscious animals. Furthermore, we have attempted to develop a miniature telemetry transmitter, which can be implanted in small animals. Special care was taken to reduce the background noise as much as possible and transmit sympathetic nerve signal without any distortion. The noise level of the novel telemetry system was several microvolts and its signal frequency band was 0.05-3 kHz, indicating that the present novel telemetry system is able to record sympathetic nerve discharge in conscious animals. However, the transmitter was too large to be implanted in smaller animals than the cat or rabbit, because its size was 4 x 5 x 0.5cm. It will be necessary to reduce the size of the transmitter by using one-tip integrated circuit. Less

为了更好地理解心血管系统的交感神经控制，测量不同血管床的交感神经流出并分析特定干预后交感神经流出的长期变化非常重要。本研究的目的是开发一种新型植入式微电极和微型遥测装置，用于稳定、长期记录自由活动的小动物的交感神经放电。我们用导电橡胶或吸水性聚合物制作了两种新型双极袖带电极，可应用于大鼠的肾神经。当微电极嵌入盐水中时，在0.05-3kHz频率范围内电极的电阻抗为2.8-9.4kΩ，对应于交感放电频带。任一电极在几周内都显示出稳定的电阻抗，这表明只要电极与神经束接触良好，阻抗就足够低，可以在低背景噪声下记录交感神经活动。由于现有的电极尺寸小（体积为2mm^3）并且易于操作，因此将每个电极植入神经上的时间较短，不会因干燥或机械损伤而造成神经损伤，并且只要用于急性类型的实验，电极就可以很好地工作。因此，新型电极可用于记录有意识的动物的交感神经放电。此外，我们还尝试开发一种微型遥测发射器，可以植入小动物体内。特别注意尽可能减少背景噪音，并在不失真的情况下传输交感神经信号。该新型遥测系统的噪声水平为几微伏，其信号频带为0.05-3kHz，表明该新型遥测系统能够记录有意识的动物的交感神经放电。然而，发射器太大，无法植入比猫或兔子更小的动物，因为它的尺寸为 4 x 5 x 0.5 厘米。有必要通过使用单端集成电路来减小发射器的尺寸。较少的

项目成果

H. Komine: "Forelimb vasodilatation induced by hypothalamic stimulation is greatly mediated with nitric oxide in anesthetized cats"Japanese Journal of Physiology. in press. (2003)

H. Komine：“麻醉猫中下丘脑刺激引起的前肢血管舒张很大程度上是由一氧化氮介导的”日本生理学杂志。

松川寛二: "新運動生理学:循環 「自律神経と心腎臓」"真興交易. 10 (2001)

Kanji Matsukawa：“新运动生理学：循环‘自主神经和心肾’”Shinko Trading 10 (2001)。

K. Matsukawa: "Motor system (in Japanese). In "Standard Physiology""Bunkou-do Press. 45 (2002)

K. Matsukawa：“运动系统（日语）。在“标准生理学””文兴堂出版社中。

K.Matsukawa: "Reflex responses in plasma catecholamines caused by static contraction of skeletal muscle"Japanese Journal of Physiology. 51. 591-597 (2001)

K.Matsukawa：“骨骼肌静态收缩引起的血浆儿茶酚胺的反射反应”日本生理学杂志。

K.Matsukawa: "Implantable microelectrodes with new electro-conductive materials for recording sympathetic neural discharge"Japanese Journal of Physiology. 53. 61-64 (2003)

K.Matsukawa：“用于记录交感神经放电的新型导电材料的植入式微电极”日本生理学杂志。