The Role of Photoreceptor Light Sensitivity in Expression of Classical Conditioning

BlackwellIBN-0077509海蛞蝓，Hermissenda crassicornis，是研究联想学习的模型系统，因为它与哺乳动物具有经典条件反射的特性。 在Hermissenda中，已经确定了单个脑细胞，其中细胞特性的变化与动物学习行为的变化相关。 具体而言，B型光感受器类别显示出兴奋性的增加，这是由于光和湍流的经典条件反射。 B型光感受器的兴奋性受响应于光而流过细胞膜的电流的影响。 该项目的目标之一是测量这种尚未充分表征的电流。 联想学习行为的表达依赖于A型和B型光感受器对光的反应之间的相互作用。 这种相互作用受到流过A型光感受器膜的光诱导电流的影响。 因此，该项目的第二个目标是测量这种电流对各种强度和持续时间的光的响应。 本研究的第三个也是最后一个目标是开发两种（A型和B型）光感受器及其相互作用的计算机模型。 模型模拟用于评估两种类型的光感受器对光的响应输出，以及B型光感受器兴奋性增加后输出的变化。该项目将大大有助于我们了解人们如何学习。 经典条件反射，也被称为巴甫洛夫条件反射，被广泛研究，因为它是一种存在于许多不同物种中的联想学习形式。细胞兴奋性的变化被认为是联想学习的一般机制，因为它已经在经典条件反射的哺乳动物脑细胞中被检测到。 然而，细胞兴奋性变化和动物行为变化之间的途径尚未完全了解。 这些证据表明，学习行为的表达源于神经元组之间复杂相互作用的调节。 这个项目开始阐明细胞特性的变化如何调节参与经典条件反射行为的神经元网络。

Lay SummaryBlackwellIBN-0077509The seaslug, Hermissenda crassicornis, is a model system for studying associative learning because it shares properties of classical conditioning with mammals. In Hermissenda, individual brain cells have been identified in which a change in cell properties is correlated with a change in animal learning behavior . Specifically, the type B class of photoreceptors shows an increase in excitability consequent to classical conditioning with light and turbulence. The excitability of the type B photoreceptor is affected by current flowing across the cell membrane in response to light. The measurement of this current, which has not been adequately characterized, is one goal of this project. The expression of associative learning behavior depends on the interaction between type A and type B photoreceptors in response to light. This interaction is affected by the light-induced current flowing across the membrane of the type A photoreceptors. Thus, a second goal of this project is to measure this current in response to light of various intensities and durations. The third and final goal of this research is to develop a computer model of both (type A and type B) classes of photoreceptors and their interaction. Model simulations are used to evaluate the output of both types of photoreceptors in response to light, and the change in output consequent to an increase in excitability in the type B photoreceptor.This project will significantly contribute to our knowledge of how people learn. Classical conditioning, also known as Pavlovian conditioning, is studied extensively because it is a form of associative learning present in many different species. A change in cell excitability is thought to be a general mechanism of associative learning because it has been detected in brain cells of mammals which have been classically conditioned. However, the pathway between change in cell excitability and change in animal behavior is not fully understood. These is evidence that expression of learning behavior emanates from modulation of the complex interaction between groups of neurons. This project begins to elucidate how changes in cell properties modulate neuronal networks involved in classical conditioning behavior.