Estimates of statistical release parameters from crayfish and frog neuromuscular junctions.
نویسندگان
چکیده
منابع مشابه
Facilitation and delayed release at single frog neuromuscular junctions.
Facilitation and delayed spontaneous release were recorded from neuromuscular junctions at 2 temperatures. In some experiments, Sr2+ substituted for Ca2+. We measured the ratio of delayed release to resting spontaneous release (D), and the ratio of the second end-plate potential amplitude to the first (F). An extension of the model of Barton et al. (1983) relating Ca2+ to evoked and spontaneous...
متن کاملPromiscuous and reversible blocker of presynaptic calcium channels in frog and crayfish neuromuscular junctions from Phoneutria nigriventer spider venom.
Peptide channel blockers found in venoms of many predators are useful pharmacological tools and potential therapeutic agents. The venom of the Brazilian spider Phoneutria nigriventer contains a fraction, omega-phonetoxin-IIA (omega-Ptx-IIA, 8360 MW), which blocks Ca2+ channels. At frog neuromuscular junctions (NMJ) bathed in normal Ca2+ (1.8 mM) saline, omega-Ptx IIA did not affect spontaneous ...
متن کاملA new sea urchin toxin and its effect on spontaneous transmitter release at frog neuromuscular junctions.
The authors extracted a dialyzable substance from sea urchin (Diadematidae) collected in Fiji, and investigated its effect on the frequency of miniature endplate potentials (MEPPs) in the sartorius muscle of the frog. This substance was shown to be different from previously known biologically active substances in many respects. The increase of MEPP frequency by the application of toxin was sign...
متن کاملSpontaneous acetylcholine release in mammalian neuromuscular junctions.
Spontaneous secretion of the neurotransmitter acetylcholine in mammalian neuromuscular synapsis depends on the Ca2+ content of nerve terminals. The Ca2+ electrochemical gradient favors the entry of this cation. We investigated the possible involvement of three voltage-dependent Ca2+ channels (VDCC) (L-, N-, and P/Q-types) on spontaneous transmitter release at the rat neuromuscular junction. Min...
متن کاملFINAL ACCEPTED VERSION JN-001555-2003.R2 Promiscuous and Reversible Blocker of Presynaptic Calcium Channels in Frog and Crayfish Neuromuscular Junctions from Phoneutria nigriventer Spider Venom
1. Dept. Physiology, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada M5S 1A8. 2. Instituto Butantan, Lab. of Pharmacology, Biochemistry and Immunochemistry, respectively, São Paulo, SP, Brazil. 3. Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON, Canada M5G 1X5. 4. Current address: Department of Biological Science, Barnard College...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1975
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1975.sp010792