Frost W N, Brandon C L, Mongeluzi D L
Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, 77225, USA.
Neurobiol Learn Mem. 1998 Mar;69(2):126-35. doi: 10.1006/nlme.1997.3816.
When repeatedly elicited, the oscillatory escape swim of the marine mollusc Tritonia diomedea undergoes habituation of the number of cycles per swim. Previous work has shown that this habituation is accompanied by sensitization of another feature of the behavior: latency to swim onset. Here we focused on the behavioral features of sensitization itself. Test swims elicited 5 min after a strong sensitizing head stimulus differed in several ways from control swims: sensitized animals had shorter latencies for gill and rhinophore withdrawal, a shorter latency for swim onset, a lower threshold for swim initiation, and an increased number of cycles per swim. Sensitized animals did not, however, swim any faster (no change in cycle period). A separate experiment found that swim onset latency also sensitized when Tritonia came into contact with one of their natural predators, the seastar Pycnopodia helianthoides, demonstrating the ecological relevance of this form of nonassociative learning. These results define the set of behavioral changes to be explained by cellular studies of sensitization in Tritonia.
当反复引发时，海生软体动物多节三趾蛞蝓（Tritonia diomedea）的振荡式逃避游泳会出现每次游泳周期数的习惯化。先前的研究表明，这种习惯化伴随着行为的另一个特征的敏感化：游泳开始的潜伏期。在这里，我们关注敏感化本身的行为特征。在强烈的敏感化头部刺激后5分钟引发的测试游泳在几个方面与对照游泳不同：敏感化的动物鳃和嗅角撤回的潜伏期更短，游泳开始的潜伏期更短，游泳起始的阈值更低，并且每次游泳的周期数增加。然而，敏感化的动物游泳速度并没有更快（周期时长没有变化）。一项单独的实验发现，当多节三趾蛞蝓与它们的一种天然捕食者——太阳海星（Pycnopodia helianthoides）接触时，游泳开始潜伏期也会敏感化，这证明了这种非联想学习形式的生态相关性。这些结果确定了一系列行为变化，有待通过对多节三趾蛞蝓敏感化的细胞研究来解释。
