Journal of Neuroscience, Vol 14, 4481-4493, Copyright © 1994 by Society for Neuroscience
Distribution of carbohydrate epitopes among disjoint subsets of leech sensory afferent neurons
K Zipser, M Erhardt, J Song, RN Cole and B Zipser
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
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.