RRC ID 11784
Author Hikima T, Araki R, Ishizuka T, Yawo H.
Title beta-Phorbol ester-induced enhancement of exocytosis in large mossy fiber boutons of mouse hippocampus.
Journal J Physiol Sci
Abstract beta-Phorbol esters (BPE), synthetic analogues of diacylglycerol (DAG), induce the potentiation of transmission in many kinds of synapses through activating the C(1) domain-containing receptors. However, their effects on synaptic vesicle exocytosis have not yet been investigated. Here, we evaluated the vesicular exocytosis directly from individual large mossy fiber boutons (LMFBs) in hippocampal slices from transgenic mice that selectively express synaptopHluorin (SpH). We found that the activity-dependent increment of SpH fluorescence (DeltaSpH) was enhanced by 4beta-phorbol 12,13-diacetate (PDAc), one of the BPEs, without influencing the recycled component of SpH. These PDAc effects on DeltaSpH were almost completely inhibited by staurosporine, a non-selective antagonist of protein kinases. However, intermittent synaptic transmission was still potentiated through a staurosporine-resistant mechanism. The staurosporine-sensitive cascade may facilitate the vesicle replenishment, thus maintaining the fidelity of transmission at a high level during repetitive firing of the presynaptic neuron.
Volume 59(4)
Pages 263-74
Published 2009-7
DOI 10.1007/s12576-009-0031-0
PMID 19340534
MeSH Animals Calcium / metabolism Excitatory Postsynaptic Potentials / drug effects Exocytosis / drug effects* Green Fluorescent Proteins / genetics Green Fluorescent Proteins / metabolism In Vitro Techniques Mice Mice, Inbred C57BL Mice, Transgenic Mossy Fibers, Hippocampal / drug effects* Mossy Fibers, Hippocampal / physiology* Phorbol Esters / pharmacology* Presynaptic Terminals / drug effects* Presynaptic Terminals / physiology* Recombinant Fusion Proteins / genetics Recombinant Fusion Proteins / metabolism Staurosporine / pharmacology Synaptic Transmission / drug effects
IF 2.757
Times Cited 1