The Dorris Neuroscience Center, Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
The Dorris Neuroscience Center, Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA.
Cold Spring Harb Protoc. 2021 Nov 1;2021(11):pdb.prot107086. doi: 10.1101/pdb.prot107086.
The tadpole visual system shows an extraordinary extent of developmental and visual experience-dependent plasticity, establishing sophisticated neuronal response properties that guide essential survival behaviors. The external development and access to the developing visual circuit of tadpoles make them an excellent experimental system in which to elucidate plastic changes in neuronal properties and their capacity to encode information about the visual scene. The temporal structure of neural activity encodes a significant amount of information, access to which requires recording methods with high temporal resolution. Conversely, elucidating changes in the temporal structure of neural activity requires recording over extended periods. It is challenging to maintain patch-clamp recordings over extended periods and Ca imaging has limited temporal resolution. Extracellular recordings have been used in other systems for extended recording; however, spike amplitudes in the developing visual circuit are not large enough to be captured by distant electrodes. Here we describe a juxtacellular tetrode recording method for continuous long-term recordings from neurons in intact tadpoles, which can also be exposed to diverse visual stimulation protocols. Electrode position in the tectum is stabilized by the large contact area in the tissue. Contamination of the signal from neighboring neurons is minimized by the tight contact between the glass capillaries and the dense arrangement of neurons in the tectum. This recording method enables analysis of developmental and visual experience-dependent plastic changes in neuronal response properties at higher temporal resolution and over longer periods than current methods.
蝌蚪的视觉系统表现出非凡的发育程度和视觉经验依赖性可塑性，形成了复杂的神经元反应特性，指导着重要的生存行为。蝌蚪外部的发育和对正在发育的视觉回路的访问使它们成为一个极好的实验系统，可以阐明神经元特性的可塑性变化及其对视觉场景信息的编码能力。神经活动的时间结构编码了大量信息，需要具有高时间分辨率的记录方法来访问这些信息。相反，阐明神经活动时间结构的变化需要进行长时间的记录。在长时间内维持膜片钳记录是具有挑战性的，钙成像的时间分辨率有限。在其他系统中已经使用了细胞外记录进行扩展记录；然而，发育中的视觉回路中的尖峰幅度不够大，无法被远距离电极捕捉。在这里，我们描述了一种用于完整蝌蚪神经元的连续长期记录的细胞外四极管记录方法，该方法也可以暴露于不同的视觉刺激方案。在组织中较大的接触面积稳定了电极在顶盖中的位置。玻璃毛细管与顶盖中密集排列的神经元之间的紧密接触最小化了来自相邻神经元信号的污染。这种记录方法能够以比当前方法更高的时间分辨率和更长的时间分析神经元反应特性的发育和视觉经验依赖性可塑性变化。
