Auckland Bioengineering Institute, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
J Neurosci Methods. 2012 Mar 15;204(2):242-8. doi: 10.1016/j.jneumeth.2011.11.019. Epub 2011 Nov 19.
The ability to monitor tissue oxygen concentration in a specific region of the brain in a freely moving animal could provide a new paradigm in neuroscience research. We have developed a fully implantable telemetry system for the continuous and chronic recording of brain tissue oxygen (PO(2,BR)) in conscious animals. A telemetry system with a sampling rate of 2kHz was combined with a miniaturized potentiostat to amperiometrically detect oxygen concentration with carbon paste electrodes. Wireless power was employed to recharge the telemeter battery transcutaneously for potential lifetime monitoring. Rats were implanted with the telemeter in the peritoneal cavity and electrodes stereotaxically implanted into the brain (striatum or medulla oblongata). While the animals were living in their home cages the sensitivity to changes in oxygen was validated by repeatedly altering the inspired oxygen (10%, 100%, respectively) or a pharmacological stimulus (carbonic anhydrase inhibitor: acetazolamide 50mg/kg IP). Basal level of PO(2,BR) was monitored for 3weeks and showed good overall stability and good correlation to movement such as grooming. During hypoxia, PO(2,BR) decreased significantly by -51%±2% from baseline, whereas it increased by 34%±3% during hyperoxia. Following the systemic administration of acetazolamide, PO(2,BR) increased by 38%±4%. We propose this new technology provides a robust method to measure changes in oxygen concentration in specific areas of the brain, in conscious freely moving rats. The ability to track long term changes with disease progression or drug treatment may be enabled.
在自由活动的动物的大脑特定区域监测组织氧浓度的能力可能为神经科学研究提供新的范例。我们已经开发了一种完全可植入的遥测系统，用于在清醒动物中连续和慢性记录脑组织氧（PO2，BR）。一个具有 2kHz 采样率的遥测系统与一个微型化的电化学池组合，通过碳糊电极安培法检测氧浓度。无线电源被用来经皮给遥测电池充电，以进行潜在的寿命监测。大鼠将遥测仪植入腹腔，电极经立体定向植入大脑（纹状体或延髓）。当动物在自己的笼子里生活时，通过反复改变吸入氧气（分别为 10%和 100%）或药理学刺激（碳酸酐酶抑制剂：乙酰唑胺 50mg/kg IP）来验证对氧变化的敏感性。监测了 3 周的基础 PO2，BR 水平，显示出良好的整体稳定性和与运动（如梳理）的良好相关性。在缺氧期间，PO2，BR 从基线下降了-51%±2%，而在高氧期间增加了 34%±3%。在全身给予乙酰唑胺后，PO2，BR 增加了 38%±4%。我们提出这项新技术为在清醒自由活动的大鼠的大脑特定区域测量氧浓度变化提供了一种强大的方法。可能能够跟踪疾病进展或药物治疗的长期变化。
