Zipser K, Erhardt M, Song J, Cole R N, Zipser B
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
J Neurosci. 1994 Jul;14(7):4481-93. doi: 10.1523/JNEUROSCI.14-07-04481.1994.
Carbohydrate recognition plays an important role in the development of normal projections of sensory afferent neurons in the leech CNS. Four different carbohydrate epitopes are expressed by sensory afferents on their 130 kDa surface proteins: all sensory afferents share a common carbohydrate epitope (CE0) that helps them to enter and project diffusely across the synaptic neuropil; a restricted expression of three other carbohydrate epitopes (CE1, CE2, and CE3) serves to distinguish three subsets of sensory afferents. We examined the subsets of sensory afferents defined by their subset carbohydrate epitopes in the leech lip, skin, gut, and CNS. We established that the CE1, CE2, and CE3 subset epitopes define disjoint subsets of neurons by double labeling sensory afferents with monoclonal antibodies for different pairs of subset epitopes. We found that CE2 and CE3 afferents populate the lip and skin, but not the gut, and that these two subsets of sensory afferents have convergent projection patterns in the CNS. We found that CE1 afferents populate the gut and skin, but not lips; furthermore, their CNS projections diverge from those of CE2 and CE3 afferents. Our data fit the hypothesis that these carbohydrate epitopes are related to sensory modality of afferent subsets.
碳水化合物识别在水蛭中枢神经系统中感觉传入神经元正常投射的发育过程中起着重要作用。感觉传入神经元在其130 kDa表面蛋白上表达四种不同的碳水化合物表位：所有感觉传入神经元共享一个共同的碳水化合物表位（CE0），该表位有助于它们进入并在突触神经毡中弥散投射；另外三种碳水化合物表位（CE1、CE2和CE3）的限制性表达用于区分感觉传入神经元的三个亚群。我们研究了水蛭唇部、皮肤、肠道和中枢神经系统中由其亚群碳水化合物表位定义的感觉传入神经元亚群。我们通过用针对不同对亚群表位的单克隆抗体对感觉传入神经元进行双重标记，确定了CE1、CE2和CE3亚群表位定义了不相交的神经元亚群。我们发现CE2和CE3传入神经元分布在唇部和皮肤，但不在肠道，并且这两个感觉传入神经元亚群在中枢神经系统中有汇聚的投射模式。我们发现CE1传入神经元分布在肠道和皮肤，但不在唇部；此外，它们在中枢神经系统中的投射与CE2和CE3传入神经元的投射不同。我们的数据符合这样的假设，即这些碳水化合物表位与传入亚群的感觉模式有关。
