Crow T
J Neurosci. 1985 Jan;5(1):215-23. doi: 10.1523/JNEUROSCI.05-01-00215.1985.
Changes in the response of B-type photoreceptors to illumination were examined in the isolated nervous systems of Hermissenda following the conditioning procedures described in the preceding paper. Analysis of the transient peak amplitude of the depolarizing generator potential at the onset of two of the three light intensities used in the behavioral studies did not reveal an enhanced photoresponse to the light. However, when the activity of the same B-photoreceptors was examined after 5 min of continuous light, there was a significant decrease in the light-adapted discharge rate and a decreased generator potential amplitude in conditioned animals as compared to the random controls. An examination of the light adapted photoresponse in preparations where spike generation and synaptic interactions were eliminated showed that the decreased photoresponse of conditioned animals was due to factors that are intrinsic to the B-photoreceptors. These results are consistent with previous work suggesting that conditioning produces substantial adaptation effects in B-photoreceptors (Crow, T. (1982) Soc. Neurosci. Abstr. 8: 824). Since the cellular changes qualitatively follow the behavioral changes and are observed at times and light intensities that are similar to those where the suppression of phototactic behavior is expressed, phototactic suppression may be directly related to the changes in the B-photoreceptors and may not require the previously proposed complex network interactions within the eyes of Hermissenda.
在前一篇论文所述的条件作用程序之后，在分离的艾氏海兔神经系统中检测了B型光感受器对光照反应的变化。对行为学研究中使用的三种光强度中的两种光强度开始时去极化发生器电位的瞬态峰值幅度进行分析，未发现对光的光反应增强。然而，当在持续光照5分钟后检测相同B型光感受器的活动时，与随机对照组相比，条件作用动物的光适应放电率显著降低，发生器电位幅度减小。在消除了动作电位产生和突触相互作用的标本中对光适应光反应进行检查，结果表明，条件作用动物光反应降低是由于B型光感受器固有的因素所致。这些结果与之前的研究工作一致，表明条件作用在B型光感受器中产生了显著的适应效应（Crow, T. (1982) Soc. Neurosci. Abstr. 8: 824）。由于细胞变化在质量上与行为变化一致，并且在与表达趋光行为抑制的时间和光强度相似的情况下观察到，趋光抑制可能与B型光感受器的变化直接相关，可能不需要先前提出的艾氏海兔眼睛内复杂的网络相互作用。
