Associative learning changes intrinsic to Hermissenda type A photoreceptors.
Associative learning changes intrinsic to Hermissenda type A photoreceptors.
复制标题
Hermissenda A 型光感受器固有的联想学习发生变化。
DOI：
10.1037//0735-7044.104.1.135
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发表时间：
1990
影响因子：
1.9
通讯作者：
Grover,LM
中科院分区：
文献类型：
--
作者：
Farley,J;Richards,WG;Grover,LM
此前，裸目软体动物Hermissanda的眼睛被证明含有两类光感受器。B型光感受器在光和旋转的重复配对后表现出增强的光反应和膜的兴奋性，并在调节联合产生的趋光行为的减少中发挥重要作用。A型光感受器也被证明会随着联想训练而改变。在之前的研究中，来自经过训练的动物的A型光感受器被发现具有减少的光反应。由于这些记录是从突触完整的细胞中获得的，因此无法确定联想训练的效果是反映了A型光感受器的突触输入的变化，还是反映了体细胞电导的内在变化。在本研究中，在训练后的保留天数内获得了来自突触分离的A型光感受器的细胞内记录，观察到配对特异性的光诱导产生电位的下降和静息输入电阻的下降。对未经训练的动物的A型光感受器的电流和电压钳分析表明，稳态光反应的一个重要决定因素是钙激活的K+电流(I K−Ca)。因此，A型光感受器似乎也是Hermissenda中关联信息存储的主要部位。提示联想训练增强K-−-Ca可能是A型感光细胞光反应减弱的原因之一。
The eyes of the nudibranch mollusc Hermissenda have previously been shown to contain 2 classes of photoreceptors. Type B photoreceptors exhibit increased light responses and membrane excitability after repeated pairings of light and rotation and play an important role in the mediation of associatively produced reductions in phototactic behavior. Type A photoreceptors have also been shown to change with associative training. In previous research, Type A photoreceptors from trained animals were found to have reduced light responses. Because these recordings were obtained from synaptically intact cells, it was not possible to determine whether the effects of associative training reflected changes in synaptic input to Type A photoreceptors or intrinsic changes in somatic conductances. In the present study, intracellular recordings from synaptically isolated Type A photoreceptors were obtained on retention days after training, and pairing-specific decreases in light-induced generator potentials and decreases in resting input resistance were observed. Current-and voltage-clamp analysis of Type A photoreceptors from untrained animals revealed that an important determinant of the steady-state light response was a calcium-activated K+ current (I K− Ca). Thus, Type A photoreceptors also appear to be a primary site for associative information storage in Hermissenda. It is suggested that enhancement of I K− Ca by associative training may contribute to the diminished light response of Type A photoreceptors.