SENSORY INTEGRATION WITHIN RETICULOMOTOR NETWORKS

运动行为障碍的神经原因通常在 受损集成电路的术语。帕金森氏症患者 例如，当基底节受到损害时，会失去精细运动控制 不再受黑质多巴胺能传入的调节。然而，几乎是一个 突如其来的刺激可能会引发非自愿的弹道行为： 病人在受到惊吓时可能会从椅子上跳起来。因此，一个突然的变化 在他们周围环境的感官图像中是立即 与电机电路集成。具体地，感官信息可以 与更原始的网状脊髓运动网络整合 产生一种适应性反应。 这些运动行为的短潜伏期排除了感觉 在响应启动后立即修改响应。因此， 必须提供持续更新的环境感官图像 用于选择或偏置随后的电机程序。我们的目标是 阐明整合过程中涉及的一些共同原则 这样的神经网络。我们希望确定一个高度专业化的 感觉系统与原始运动系统集成在一起，以允许 动物持续监测其环境，生产精准 弹道行为。大鼠逃逸系统的电感觉调制 FISH是一种相关的、在实验上易于处理的神经类型 整合。 众所周知，硬骨动物的电感觉系统被用于 电子定位、社交、控制干扰避免 横向和纵向时的响应和电机控制 追踪。Mauthner(M-)细胞，一对双侧延髓神经元 用于启动惊吓反应，即使在原始人类中也存在 鱼。虽然过去的研究发现听觉、视觉和侧线 M细胞的传入，我们最近已经表明，电感 可以调节电生裸体鱼的惊吓反应。 来自M细胞抑制性轴突帽的生理记录 突触电位对幅度调制的反应 鱼的电信号。本项目的具体目标是：1) 通过观察电感觉线索对惊吓的影响 线索持续时间、壶腹(低频)或 块茎(高频)刺激和干扰刺激对 回应。2)急性实验将决定M的偏侧化。 同时从两者的轴突帽记录对细胞的抑制 M细胞，同时复制与行为最相关的刺激。3) 对自由行为的鱼的长期记录将验证这种整合 在调节惊吓反应中的电感觉环境。

The neural causes of dysfunctional motor behavior are often addressed in terms of impaired integrative circuitry. Parkinsonian patients, for example, suffer a loss of fine motor control when the basal ganglia are no longer regulated by nigral dopaminergic afferents. Yet, an almost involuntary, ballistic behavior can be elicited by a sudden stimulus: patients may leap from their chair when startled. Thus, an abrupt change in the sensory image of their surrounding environment is immediately integrated with motor circuitry. In particular, sensory information may be integrated with the more primitive reticulospinal motor network to generate an adaptive response. The short latencies of these motor behaviors preclude sensory modification of the response immediately after it is initiated. Thus, a continuously updated sensory image of the environment must be available for use in selecting or biasing the ensuing motor program. Our goal is to elucidate some of the common principles involved in the integration of such neural networks. We hope to determine how a highly specialized sensory system is integrated with a primitive motor system to allow an animal to continuously monitor its environment and produce accurate ballistic behaviors. Electrosensory modulation of the escape system in fish is a relevant and experimentally tractable type of neural integration. The teleostean electrosensory system is known to be used for electrolocation, social communication, control of the Jamming Avoidance Response, and electromotor control during lateral and longitudinal tracking. The Mauthner (M-) cells, a bilateral pair of medullary neurons used to initiate the startle response, are present even in primitive fishes. While past studies have found auditory, visual, and lateral line afferents to the M-cells, we have recently shown that the electrosense can modulate the startle response of electrogenic gymnotiform fish. Physiological recordings from the inhibitory axon cap of the M-cell have demonstrated synaptic potentials in response to amplitude modulations of the fish's electric signal. The specific aims of this project are to 1) examine the influences of electrosensory cues on startle by looking at the effect of cue duration, the roles of ampullary (low frequency) or tuberous (high frequency) stimuli, and jamming stimuli on modulating the response. 2) Acute experiments will determine the lateralization of M- cell inhibition by simultaneously recording from the axon caps of both M-cells while reproducing the most behaviorally relevant stimuli. 3) Chronic recordings in freely behaving fish will verify the integration of the electrosensory surround in modulating the startle response.