Gelperin Alan, Ambrosini Anthony E
Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544.
J Undergrad Neurosci Educ. 2021 Dec 24;20(1):A88-A99. eCollection 2021 Fall.
H1, a very well-studied insect visual interneuron, has a panoramic receptive field and is directionally selective in responding to optic flow. The synaptic basis for the directional selectivity of the H1 neuron has been studied using both theoretical and cellular approaches. Extracellular single-unit recordings are readily obtained by beginning students using commercially available adults of the grey flesh fly . We describe an apparatus which allows students to present a series of moving visual stimuli to the eye of the restrained, minimally dissected adult , while recording both the single unit responses of the H1 neuron and the position and velocity of the moving stimulus. Students obtain quantitative and reproducible responses of H1, probing the response properties of the neuron by modulating stimulus parameters such as: direction and speed of movement, visual contrast, spatial wavelength, or the extent of the visual field occupied. Students learn to perform quantitative analysis of their data and to generate graphical representations of their results characterizing the tuning and receptive field of this neuron. This exercise demonstrates the utility of single unit recording of an identified interneuron in an awake restrained insect and promotes interpretation of these results in terms of the visual stimuli normally encountered by freely flying flies in their natural environment.
H1是一种研究得非常透彻的昆虫视觉中间神经元，具有全景感受野，并且在对光流的反应中具有方向选择性。已经使用理论和细胞方法研究了H1神经元方向选择性的突触基础。刚开始学习的学生使用市售的灰肉蝇成虫很容易就能获得细胞外单单元记录。我们描述了一种仪器，它能让学生在记录H1神经元的单单元反应以及移动刺激的位置和速度的同时，向被束缚的、经过最少解剖的成虫眼睛呈现一系列移动视觉刺激。学生们获得H1的定量且可重复的反应，通过调节刺激参数（如：移动方向和速度、视觉对比度、空间波长或所占据视野的范围）来探究神经元的反应特性。学生们学会对自己的数据进行定量分析，并生成结果的图形表示，以表征该神经元的调谐和感受野。这个实验展示了在清醒且被束缚的昆虫中对已识别中间神经元进行单单元记录的实用性，并促进根据自由飞行的苍蝇在自然环境中通常遇到的视觉刺激来解释这些结果。
