Synaptic Plasticity at the Mammalian Neuromuscular Junction

在正常的出生后发育过程中， 经历一个有序的突触消除过程， 纤维失去了所有，但其中一个多突触， 在出生时。 货车埃森博士将研究突触的几个方面， 特异性和可塑性在比目鱼肌的兔子，使用 各种解剖和生理技术。 一个目的是 以确定两个不同的运动群体 神经元（快或慢）支配它们各自的种群， 肌肉纤维 他将确定错配的发生率 连接（快速运动轴突连接到慢速肌肉纤维，反之亦然） 在广泛的多神经支配阶段，他将测试 突触数量的差异最初在快速和 慢纤维 另一个目标是研究区域分布 肌肉纤维在个别运动单位，并确定 肌肉内的这种分布是否在这段时间内发生变化， 突触消失的过程 最后，货车埃森博士将决定 神经肌肉连接在晚期会发生变化， 出生后的发展，当许多肌肉纤维被称为转换 由快收缩型转为慢收缩型。 这些研究可以提供 关于突触可塑性的细胞基础的宝贵见解 以及控制突触有序重排的规则 连接.

During normal postnatal development, mammalian skeletal muscles undergo an orderly process of synapse elimination, whereby each muscle fiber loses all but one of the multiple synapses with which it starts at birth. Dr. Van Essen will study several aspects of synaptic specificity and plasticity in the soleus muscle of the rabbit, using a variety of anatomical and physiological techniques. One objective is to ascertain the way in which two distinct populations of motor neurons (fast or slow) innervate their respective populations of muscle fibers. He will determine the incidence of mismatched connections (fast motor axons onto slow muscle fibers and vice versa) during the stage of extensive polyinnervation, and he will test for differences in the number of synapses initially made onto fast and slow fibers. Another objective is to study the regional distribution of muscle fibers within individual motor units and to ascertain whether this distribution within the muscle changes during the period of synapse elimination. Finally, Dr. Van Essen will determine whether there are changes in neuromuscular connections during a period of late postnatal development, when many muscle fibers are known to convert from fast to slow contractile type. These studies may provide valuable insights concerning the cellular basis of synaptic plasticity and the rules governing orderly rearrangements of synaptic connections.