The cellular mechanism that underlies the regulated release of synaptic ves
icles during neurotransmission is not fully known. Our previous data has sh
own that brain spectrin (alpha SpII Sigma 1/beta SpII Sigma 1)(2) is locali
zed in axons and nerve terminals and we have shown that the beta subunit (b
eta SpII Sigma 1) contains a synapsin-binding domain capable of interacting
with synapsin and small synaptic vesicles in vitro and in vivo. These find
ings suggested a role for brain beta-spectrin in synaptic neurotransmission
To examine this possibility further, peptide-specific antibodies directed
against epitopes within the synapsin-binding domain of brain beta-spectrin,
or against flanking regions, were injected into the presynaptic neuron of
synaptically paired rat hippocampal neurons in culture. Here, we show that
the antibodies directed against the synapsin-binding domain specifically bl
ocked synaptic neurotransmission. (C) 2000 Published by Elsevier Science B.
V. All rights reserved.