scholarly journals Modulation of spontaneous transmitter release from the frog neuromuscular junction by interacting intracellular Ca2+ stores: critical role for nicotinic acid-adenine dinucleotide phosphate (NAADP)

2003 ◽  
Vol 373 (2) ◽  
pp. 313-318 ◽  
Author(s):  
Eugen BRAILOIU ◽  
Sandip PATEL ◽  
Nae J. DUN
Keyword(s):  
Neuromuscular Junction ◽  
Nicotinic Acid ◽  
Transmitter Release ◽  
Critical Role ◽  
Cell Types ◽  
Functional Coupling ◽  
Frog Neuromuscular Junction ◽  
Wide Range ◽  
Sphingosine 1 Phosphate ◽  
First Time

Nicotinic acid–adenine dinucleotide phosphate (NAADP) is a recently described potent intracellular Ca2+-mobilizing messenger active in a wide range of diverse cell types. In the present study, we have investigated the interaction of NAADP with other Ca2+-mobilizing messengers in the release of transmitter at the frog neuromuscular junction. We show, for the first time, that NAADP enhances neurosecretion in response to inositol 1,4,5-trisphosphate (IP3), cADP-ribose (cADPR) and sphingosine 1-phosphate (S1P), but not sphingosylphosphorylcholine. Thapsigargin was without effect on transmitter release in response to NAADP, but blocked the responses to subsequent application of IP3, cADPR and S1P and their potentiation by NAADP. Asynchronous neurotransmitter release may therefore involve functional coupling of endoplasmic reticulum Ca2+ stores with distinct Ca2+ stores targeted by NAADP.

Intraterminal Ca2+ and Spontaneous Transmitter Release at the Frog Neuromuscular Junction

2001 ◽  
Vol 85 (1) ◽  
pp. 287-294 ◽  
Author(s):  
J. K. Angleson ◽  
W. J. Betz
Keyword(s):  
Neuromuscular Junction ◽  
Phorbol Ester ◽  
Intracellular Recording ◽  
Transmitter Release ◽  
The Other ◽  
Nerve Terminals ◽  
Frog Neuromuscular Junction ◽  
Tetraacetic Acid ◽  
Ratiometric Imaging ◽  
The Relationship

We investigated the relationship between intraterminal Ca2+concentration ([Ca2+]i) and the frequency of miniature end plate potentials (MEPPs) at the frog neuromuscular junction by use of ratiometric imaging of fura-2-loaded nerve terminals and intracellular recording of MEPPs. Elevation of extracellular [KCl] over the range of 2–20 mM resulted in increases in [Ca2+]i and MEPP frequency. Loading terminals with the fast and slow Ca2+-buffers bis-( o-aminophenoxy)- N,N,N′,N′-tetraacetic acid-acetoxymethyl (BAPTA-AM) and EGTA-AM resulted in equivalent reductions in the KCl-dependent increases in MEPP frequency. The [Ca2+]i dependence of MEPP frequency determined by elevation of [Ca2+]i due to application of 0.1–10 μM ionomycin was similar to that determined when [Ca2+]i was raised by increasing extracellular KCl. Measurements in 10 mM extracellular KCl revealed that application of the phorbol ester phorbol 12 myristate 13-acetetate (PMA) caused an increase in MEPP frequency while the inactive analogue, 4α-PMA, did not. PMA application also caused an increase in [Ca2+]i. The relationship between [Ca2+]i and MEPP frequency in PMA was the same as was determined by the other methods of raising [Ca2+]i. Under all conditions tested, our data revealed a low [Ca2+]i threshold for activation of transmitter release and are consistent with a K d for [Ca2+]i on the order of 1 μM.

scholarly journals Acetylcholine-Induced Inhibition of Presynaptic Calcium Signals and Transmitter Release in the Frog Neuromuscular Junction

2016 ◽  
Vol 7 ◽  
Author(s):  
Eduard Khaziev ◽  
Dmitry Samigullin ◽  
Nikita Zhilyakov ◽  
Nijaz Fatikhov ◽  
Ellya Bukharaeva ◽  
...  
Keyword(s):  
Neuromuscular Junction ◽  
Transmitter Release ◽  
Frog Neuromuscular Junction ◽  
Calcium Signals ◽  
Presynaptic Calcium
Sign in / Sign up

Export Citation Format

Share Document