LEECH LOCAL BENDING: UNDERSTANDING A SENSORY MOTOR LOOP

动物不断地处理环境提示并对其做出反应。水蚤非常适合于感觉运动整合的研究，因为人们可以监测它们在正在进行的行为中的神经元活动，并计算出神经元回路的详细连接。此外，水蚤似乎使用与其他感觉-运动系统相同的种群代码。为了确定水蛭中枢神经系统使用的矢量计算的性质，电压敏感染料将识别中间神经元，并表征运动神经元之间的抑制连接如何影响运动控制；所有连接将得到电生理学确认。肌电图术将被用来测量弯曲的幅度和方向，以响应局部接触到水蚤的体壁。然后在电路中不加抑制地检查弯曲响应。网络的计算模型将被用来测试不同的种群编码策略和去除抑制的效果。总而言之，实验和建模的结果应该确定水蚤神经系统用来处理感觉输入到直接行为输出的代码的类型，并将显示抑制在形成向量代码中的功能。

Animals constantly process and respond to environmental cues. Leeches are well suited for studies of sensorimotor integrations because one can monitor their neuronal activity during ongoing behavior and work out detailed connectivity for the neuronal circuits. Moreover, leeches appear to use the same kind of population codes as are found in other sensory- motor systems. To determine the nature of the vector calculations used by the leech CNS, voltage sensitive-dyes will identify interneurons and characterize how inhibitor connections among motor neurons influence motor control; all connections will be confirmed electrophysiologically. Electromyography will be used to measure bend amplitude and direction in response to localized touches delivered to the leech body wall. Then the bending response will be examined without inhibition in the circuit. Computational models of the network will be used to test different population coding strategies and the effects of removing inhibition. Collectively, the results of the experiments and modeling should identify the type of code the leech nervous system uses to process sensory input to direct behavioral output and will show the function of inhibition in forming the vector code.