NEURONAL STRUCTURE AND FUNCTION IN A SENSORY PROCESSOR

其目标是了解神经网络如何处理与生物相关的 感官信息和协调适应性行为反应。这个 自那以后，电动鱼感一直被选为模型系统，尽管 它相对简单，它与听力和听觉的基本设计原则相同 高等动物的视力。我们想要继续细胞内的研究 弱电鱼类中脑区神经元的相互联系 对形态特征的生理反应特性。 电动鱼评估调制的幅度和相位的 由于自身电信号的干扰而产生的电信号 与邻居的器官放电(EOD)。相似，但在空间上 相位和幅度的变化调制是由移动的物体引起的， 并且这样的物体的检测可能因干扰而受到损害 EOD。与猫头鹰的听觉系统非常相似，相位和幅度 信息由不同的神经元通道编码和处理，直到 中脑的水平。然后，将这两种形式的信息组合在一起，以便 控制行为反应。 生理上识别的神经元通过细胞内注射进行标记 HRP或荧光黄的光镜下研究 以确定它们的形态特征，如层流位置 胞体、树突组织和投射目标。我们会 尝试将树枝状形态的差异与差异联系起来 在功能性质上，如对相位或幅度的敏感性 调制，对相位和时间的时空调制的敏感性 描述移动物体的效果的幅度，以及 目标检测对干扰的脆弱性。 特别令人感兴趣的是：1)丘脑5层和7层的神经元 中脑环似乎只接收到相位信息 它们的树突侵入第6层的程度，在那里相位信息 从后脑到达，信号相位的差异 从体表的不同部位传递的数据进行了计算。2)层流 检测运动物体的总神经元的位置和形态 对具有特定频率关系的干扰信号也很敏感 动物自己的排泄物。

The goal is to understand how neural networks process biologically relevant sensory information and orchestrate adaptive behavioral responses. The electric sense of fish has been chosen as a model system since, in spite of its relative simplicity, it shares basic design principles with hearing and vision in higher animals. We want to continue intracellular studies of neurons in the midbrain region of weakly electric fish in order to relate physiological response properties to morphological features. Electric fish evaluate modulations in the amplitude and phase of the electric signal that results from the interference of their own electric organ discharges (EODs) with those of neighbors. Similar, but spatially varying modulations in phase and amplitude are caused by moving objects, and the detection of such objects may thus be impaired by interfering EODs. Much as in the auditory system of the owl, phase and amplitude information are coded and processed by separate neuronal channels up to the level of the midbrain. Both forms of information are then combined for the control of behavioral responses. Physiologically identified neurons are labelled by intracellular injection of either HRP or Lucifer Yellow and studied under the light microscope in order to determine their morphological features, such as laminar location of somata, dendritic organization and targets of projection. We will attempt to correlate differences in dendritic morphology with differences in functional properties, such as sensitivity to either phase or amplitude modulations, sensitivity to spatio-temporal modulations of phase and amplitude that characterize the effects of moving objects, and vulnerability of object detection to jamming. Of particular interest are: 1) Neurons of laminae 5 and 7 of the mesencephalic torus that appear to receive phase information only to the extent that their dendrites invade lamina 6, where phase information arrives from the hindbrain and where differences in the phase of signals relayed from different parts of the body surface are computed. 2) Laminar location and morphology of total neurons that detect moving objects but also are sensitive to jamming signals with particular frequency relations to the animal's own EOD.