清醒大鼠海马内theta波的自适应波束形成定向计算

目的：利用波速形成算法研究大鼠海马中theta波的传播规律。方法 ：探讨了自适应波速形成算法在大鼠场电位中的应用。选取了5只大鼠,在大鼠的海马中植入8×2阵列的微丝电极阵列,训练大鼠做静止、跑动、攀爬等动作,利用视屏跟踪系统监视大鼠活动,神经信号记录仪记录大鼠的海马神经元放电和场电位,利用自适应波束形成算法分析theta波对记录电极的到达角。结果：在大鼠静止时无theta波,运动时存在明显的theta波,其传播角度保持稳定。本研究确认了theta波在海马中以行波的方式传播,传播的角度可以通过波束形成算法计算。结论：通过应用在雷达和声纳技术广泛使用的波束形成算法,能够简便的计算theta波相对于电极阵列的到达角,可能为手术电极定位提供辅助。

Calculation of Theta Wave Direction Using Adaptive Beamforming in the Hippocampus of Awake Rats

Objective： To study the traveling pattern of theta wave in hippocampus of rats using beamforming method.Methods： Micro-wire electrodes in 8？á2 array were implanted in 5 rats.An adaptive beamforming algorithm was utilized to calculate the direction of arrival（DOA） of theta wave,recorded from a neural signal recording system,relative to the linear array of recording electrodes when the rats were at rest,running and climbing.A video camera was applied to monitor the rats＇ activities.Results： When the rats were at rest,there was no theta rhythm;when the rats were moving,theta rhythms were apparent and the corresponding DOAs were stable.This study provides additional evidence to the recent finding that theta wave is traveling inside hippocampus,and introduces the beamforming algorithm to the biological study of rats＇ brain.Conclusions： The proposed DOA method which has been widely used in radar and sonar may help locate the electrode in implantation surgery.