| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2003: ¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 2002: ¥9,200,000 (Direct Cost: ¥9,200,000)
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| Research Abstract |
Neurotransmitter release is triggered by Ca^<2+> entered into presynaptic nerve terminals through voltage-dependent Ca^<2+> channels activated by an action potential. Recently, various proteins were found in presynaptic terminals. For example, SNARE proteins which form a core complex and involved in synaptic vesicle exocytosis, synaptic vesicle proteins or synaptic vesicle associated with Ca^<2+>sensor proteins, active zone cytomatrix proteins that also form a complex and motor proteins that may mobilize synaptic vesicles, and Ca^<2+> channel interacting proteins which may control Ca^<2+> channel activity.
To examine possible roles of these proteins in regulation of synaptic transmission efficiency, we employed synapses formed between rat superior cervical ganglion neurons in long-term culture. We introduced exogenous synthesized peptides or, protein, or transfected cDNAs of a presynaptic protein and monitored changes in synaptic transmissionby recording excitatory postsynaptic potentials generated by presynaptic action potentials. We revealed a mechanism of regulation of SNARE complex formation by binding of Ca^<2+>/Calmodulin to syntaxin IA^<1)>, functional differences between three types of Ca^<2+> channels expressed in the brain^<2)> a possible role of cytomatrix proteins at the active zone^<3)>, regulation of exocytosis by SV2 binding to a Ca^<2+> sensor synaptotagmin^<4)>, regulation of exocytosis by G-protein βγ subunit binding to N-type Ca^<2+> channel^<5)>, regulation of synaptic vesicle trafficking by myosin IIB but not by IIA, Va or Vb (preparing for re-submission).
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