Evaluation of Environmental Amenity for Animals based on Variability of Parameter of Physiological Function.

(1)以鸡胚为实验动物模型，研究了鸡胚的生理功能和生长情况，以评价孵育前卵贮藏和孵育早期不转蛋的不利影响。(2)利用激光位移仪在蛋壳上两个位置同时测量的弹道信号，在计算机屏幕上描绘出二维心源性弹道轨迹。(3)利用电磁感应线圈（螺线管）和小型永磁体作为传感器，开发了另一种测量鸡蛋心源性弹道运动（BCG）的简单方法。通过数值模型分析设计了测量系统，成功地从鸡胚中测量出了BCG。(4)利用超声心动图技术建立了一套无创瞬时心率（IHR）测量系统，测定了孵育后半期单个鸡胚的瞬时心率及其变异性。特征性的短暂性心动过缓发生在14-15天，随着胚胎进一步发育，心律变得更加不规律。自主神经药物静脉给药实验显示，自主神经的功能发育与独特的胚胎心律失常和心率变异性（HRV）没有关系。这些新的证据提示我们进一步研究阐明HRV。(5)我们假设空气中38℃的最佳孵育温度为胚胎发育最适宜的温度，且该温度下HRV最大。在38ºC的空气环境和不同环境（低温或高温、缺氧或高氧环境）下测定胚胎的IHR和HRV。初步结果表明，在改变的环境下，HRV降低，详细的实验正在进行中。

(1) As an experimental animal model, chick embryos were investigated for their physiological functions and growth to evaluate sdverse effects of pre-incubation egg storage and failure to turn eggs during the early incubation period.(2) Two-dimensional cardiogenic ballistic trajectories were elucidated by depicting them on a computer monitor screen from ballistic signals measured simultaneously at two sites on the eggshell with laser displacement meters.(3) Another simple method to measure the cardiogenic ballistic movements (BCG) of eggs was developed by taking advantage of an electromagnetic induction coil (solenoid) and small permanent magnet as a sensor. Numerical model analysis was made to design a measuring system and the BCG was successfully measured from late chick embryos.(4) A noninvasive system of instantaneous heart rate (IHR) was developed using acoustocardiogram and determined the IHR and its variability of individual chick embryos during the last half of incubation. Characteristic, transient bradycardia was found to occur on days 14-15 and the embryonic cardiac rhythm became more arrhythmic with further development. Experiments using intravenous administration technique of autonomic drugs showed no relationship between functional development of autonomic nerves and unique embryonic arrhythmia and heart rate variability (HRV). These new evidences prompt us further study to elucidate the HRV.(5) It was hypothesized that the optimal incubation temperature (38ﾟC) in air provides developing embryos with the most favorable amenity and the HRV is at maximum in the favorable amenity. The IHR and HRV of developing embryos were determined at 38ﾟC in air and during acute exposure to altered environments (low or high temperature, and hypoxic or hyperoxic environment). Preliminary results indicate that the HRV decreases in an altered environment and detailed experiments are in progress.