INFORMATION PROCESSING IN LAMINATED NEURONAL NETWORKS

我们计划继续研究 神经元的性质及其对加工的意义 感官信息 裸形目鱼类的电感觉系统 作为本研究的模型系统。 我们将探讨 神经元的结构和功能之间的关系 生理学鉴定的细胞的细胞内标记。 使用 发射器的小的局部离子电渗应用或其 各自的拮抗剂和通过同时细胞外记录 从单个神经元，我们打算研究网络特性， 是由于特定发射器的作用。 我们将集中在三个中枢神经结构，前起搏器 中脑的起搏核（pacemaker nucleus，PN） 延髓，和电感觉侧线叶（ELL）的 后脑 PPN包含两种功能不同的前运动神经元 控制PN的放电频率的系统，一个用于 诱导频率的平滑变化，一个用于引发突变， 瞬时加速度或“啁啾”。 两种频率 调制响应于邻居的电信号而发生。 然而，啁啾声是由动物体内高浓度的 等级顺序 它们在男性中的发生是由以下因素促进的： 睾酮和血清素抑制。 血清素抑制剂， 例如麦角新碱，促进啁啾。 小，地方 PPN的激动剂和拮抗剂的应用及其 传入结构，并通过同时记录从单一的 神经元相关的啁啾，我们想找出潜在的 结构以及神经传递的机制， 系统 ELL是第一个处理站， 信息. 它包含身体上有感受野的神经元 面 这些领域的时空动态是 由递减循环输入调制。 的机理 调制可以在单细胞水平上通过局部 递质及其拮抗剂的应用。

We plan to continue our studies of structural and functional properties of neurons and their significance for the processing of sensory information. The electrosensory system of gymnotiform fish serves as a model system for this research. We will explore relationships between the structure and function of neurons by intracellular labelling of physiologically identified cells. Using small, local iontophoretic applications of transmitters or their respective antagonists and by simultaneous extracellular recording from single neurons, we intend to study network properties that are due to the actions of specific transmitters. We will focus on three central nervous structures, the prepacemaker nucleus (PPN) of the midbrain, the pacemaker nucleus (PN) of the medulla, and the electrosensory lateral line lobe (ELL) of the hindbrain. The PPN contains two functionally different premotor systems to control the discharge frequency of the PN, one for inducing smooth changes in frequency, and one for eliciting abrupt, transient accelerations, or 'chirps'. Both forms of frequency modulations occur in response to electric signals of neighbors. Chirps, however, are exclusively produced by animals high in the rank order. Their occurrence in males is facilitated by testosterone and inhibited by serotonin. Serotonin inhibitors, such as methysergide, therefore, promote chirping. By small, local applications of agonists and antagonists to the PPN and its afferent structures, and by simultaneous recording from single neurons related to chirping, we want to identify the underlying structures as well as the mechanisms of neurotransmission in this system. The ELL is the first processing station for electrosensory information. It contains neurons with receptive fields on the body surface. The spatial and temporal dynamics of these fields are modulated by descending recurrent input. The mechanism of this modulation can be studied at the single-cell level by local application of transmitters and their antagonists.