Publication Date:
2000-07-21
Description:
Guanosine 5'-triphosphate (GTP)-binding proteins (G proteins) are involved in exocytosis, endocytosis, and recycling of vesicles in yeast and mammalian secretory cells. However, little is known about their contribution to fast synaptic transmission. We loaded guanine nucleotide analogs directly into a giant nerve terminal in rat brainstem slices. Inhibition of G-protein activity had no effect on basal synaptic transmission, but augmented synaptic depression and significantly slowed recovery from depression. A nonhydrolyzable GTP analog blocked recovery of transmission from activity-dependent depression. Neither effect was accompanied by a change in presynaptic calcium currents. Thus, G proteins contribute to fast synaptic transmission by refilling synaptic vesicles depleted after massive exocytosis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Takahashi, T -- Hori, T -- Kajikawa, Y -- Tsujimoto, T -- New York, N.Y. -- Science. 2000 Jul 21;289(5478):460-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurophysiology, University of Tokyo Faculty of Medicine, Tokyo 113-0033, Japan. ttakahas-tky@umin.ac.jp〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10903208" target="_blank"〉PubMed〈/a〉
Keywords:
Action Potentials
;
Animals
;
Brain Stem/metabolism
;
Calcium/metabolism
;
Excitatory Postsynaptic Potentials
;
Exocytosis
;
GTP-Binding Proteins/*physiology
;
Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
;
Guanosine Diphosphate/*analogs & derivatives/pharmacology
;
Guanosine Triphosphate/metabolism
;
In Vitro Techniques
;
Patch-Clamp Techniques
;
Presynaptic Terminals/metabolism
;
Rats
;
Rats, Wistar
;
*Synaptic Transmission
;
Synaptic Vesicles/*metabolism
;
Thionucleotides/pharmacology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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