Hemmi Jan M, James Andrew, Taylor W Rowland
Visual Sciences, Research School of Biological Sciences and Centre for Visual Sciences, Australian National University, Canberra, Australia.
J Vis. 2002;2(9):608-17. doi: 10.1167/2.9.3.
In behavioral tests, tammar wallabies (Macropus eugenii) are dichromats. We investigated the neural basis for this color discrimination by making patch clamp recordings from retinal ganglion cells in an in vitro preparation. Pseudo-random noise stimuli were used to probe the spectral and temporal properties of the receptive fields. Color opponent ganglion cells were excited by medium wavelength-sensitive cones and inhibited by short wavelength-sensitive cones, and were classified as M-on/S-off cells. The S-off response was delayed by 15 ms relative to the M-on response, but, otherwise, the time course of the two responses was very similar. Second-order nonlinear response components, estimated by nonlinear systems analysis, served to accentuate the color opponency. Possible synaptic mechanisms underlying the cone opponent inputs are discussed.
在行为测试中，帚尾袋貂（Macropus eugenii）是二色视动物。我们通过在体外制备物中对视网膜神经节细胞进行膜片钳记录，研究了这种颜色辨别能力的神经基础。使用伪随机噪声刺激来探测感受野的光谱和时间特性。颜色拮抗神经节细胞由中波敏感视锥细胞兴奋，并由短波敏感视锥细胞抑制，被分类为M-开/S-关细胞。S-关反应相对于M-开反应延迟了15毫秒，但除此之外，两种反应的时间进程非常相似。通过非线性系统分析估计的二阶非线性反应成分有助于增强颜色拮抗作用。文中讨论了视锥细胞拮抗输入背后可能的突触机制。
