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Synapse formation between identified leech neurons

The formation of patterns of functionally appropriate chemical synapses is one of the key aspects of nervous system development. I have investigated the cellular interactions that culminate in the formation of an inhibitory synapse between the R and P neurons of the leech. These neurons may be isolated and maintained in culture, where they reform synaptic connections under easily manipulable conditions. An early event in the formation of this synapse is the loss from sites of contact in the postsynaptic P cell of an excitatory response to the transmitter serotonin. The loss of this response was triggered specifically by contact with the presynaptic R neuron, and not by contact with other leech neurons, including other serotonergic neurons. Furthermore, contact with the R neurons of the reproductive ganglia, which do not innervate P cells, was also ineffective in causing the loss of response. This highly specific cellular interaction was prevented by treatment of the R cell surface with the proteolytic enzyme trypsin or with the lectin wheat germ agglutinin (WGA), suggesting involvement of an R cell surface glycoprotein. WGA blocked not only the loss of the excitatory response, but also prevented the formation of the R-P synapse. An antibody library against the R cell generated using a novel phage-display system produced antibodies which bound to subsets of leech neurons, including the R neurons, but none of these was specific for the R cells. I conclude that an early event in the formation of the R-P synapse is the recognition by the P cell of its correct synaptic partner through an R cell-specific surface molecule.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.28848
Date January 1994
CreatorsMerz, David C. (David Christian)
ContributorsDrapean, Pierre (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageDoctor of Philosophy (Department of Biology.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001462474, proquestno: NN05757, Theses scanned by UMI/ProQuest.

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