Department of Biomedical Engineering, University of Minnesota, Minneapolis MN, USA.
Front Neural Circuits. 2012 Jun 27;6:39. doi: 10.3389/fncir.2012.00039. eCollection 2012.
The brain is a densely interconnected network that relies on populations of neurons within and across multiple nuclei to code for features leading to perception and action. However, the neurophysiology field is still dominated by the characterization of individual neurons, rather than simultaneous recordings across multiple regions, without consistent spatial reconstruction of their locations for comparisons across studies. There are sophisticated histological and imaging techniques for performing brain reconstructions. However, what is needed is a method that is relatively easy and inexpensive to implement in a typical neurophysiology lab and provides consistent identification of electrode locations to make it widely used for pooling data across studies and research groups. This paper presents our initial development of such an approach for reconstructing electrode tracks and site locations within the guinea pig inferior colliculus (IC) to identify its functional organization for frequency coding relevant for a new auditory midbrain implant (AMI). Encouragingly, the spatial error associated with different individuals reconstructing electrode tracks for the same midbrain was less than 65 μm, corresponding to an error of 1.5% relative to the entire IC structure (4-5 mm diameter sphere). Furthermore, the reconstructed frequency laminae of the IC were consistently aligned across three sampled midbrains, demonstrating the ability to use our method to combine location data across animals. Hopefully, through further improvements in our reconstruction method, it can be used as a standard protocol across neurophysiology labs to characterize neural data not only within the IC but also within other brain regions to help bridge the gap between cellular activity and network function. Clinically, correlating function with location within and across multiple brain regions can guide optimal placement of electrodes for the growing field of neural prosthetics.
大脑是一个密集连接的网络，依赖于内部和跨多个核的神经元群体来对导致感知和行动的特征进行编码。然而，神经生理学领域仍然以单个神经元的特征描述为主，而不是跨多个区域进行同时记录，并且没有对其位置进行一致的空间重建，以便在研究之间进行比较。有复杂的组织学和成像技术可用于进行大脑重建。然而，需要的是一种在典型神经生理学实验室中相对容易且廉价的实施方法，并为电极位置提供一致的识别，以便在研究和研究小组之间广泛用于汇总数据。本文介绍了我们在豚鼠下丘脑中重建电极轨迹和位置的这种方法的初步开发情况，以确定其与新的听觉中脑植入物（AMI）相关的频率编码的功能组织。令人鼓舞的是，不同个体重建同一中脑的电极轨迹的空间误差小于 65 μm，相对于整个 IC 结构（~4-5 毫米直径的球体）的误差约为 1.5%。此外，三个采样的中脑的 IC 重建频率层始终对齐，表明能够使用我们的方法在动物之间组合位置数据。希望通过进一步改进我们的重建方法，它可以在神经生理学实验室中用作标准协议，不仅可以在 IC 内，还可以在其他脑区中对神经数据进行特征描述，以帮助缩小细胞活动和网络功能之间的差距。从临床角度来看，将功能与多个脑区的位置相关联可以为神经假体领域的电极最佳放置提供指导。
