Glutamatergic postsynaptic block by Pamphobeteus spider venoms in crayfish

Araque, Alfonso; Ferreira, Wagner Luis; Lucas, Silvia; Buño, Washington

doi:10.1016/0006-8993(92)90515-b

Cited by 10 publications

(3 citation statements)

References 26 publications

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“…Recently, Araque et al (34) have shown that PPTX, a spider toxin that specifically blocks the postsynaptic Glu receptor-channel complex, reduced mean MPP amplitude without affecting mean MPP frequency in the crayfish opener neuromuscular synapse. In contrast, it is accepted that mean MPP frequency is exclusively controlled by the presynaptic terminal (33), and it has been suggested that evoked and spontaneous transmitter release involve different mechanisms (33,35 (3,8,26) and indicating that both excitatory and inhibitory neuromuscular transmission in crayfish are mediated by the P-type VDCC.…”

Section: Discussionmentioning

confidence: 99%

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

Araque

Clarac

Buño

1994

Proc. Natl. Acad. Sci. U.S.A.

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The toxin fraction (FIX) and peptide to-Aga-WA from the venom of the funnel-web spider Agelenopsis aperta, as well as a synthetic analogue ofFX, speciically block the P-type voltage-dependent Cam channel (VDCC). The effects of these toxins on synaptic transmission were studied in the neuromuscular synapses of the crayfish opener muscle, which has a single excitatory and a single inhibitory motoneuron. FIX selectively and reversibly blocked excitatory and inhibitory stsynaptic currents and potentials in a dosedependent manner. FIX had no effect on ( The crayfish opener neuromuscular system is a particularly well-suited preparation to define the type of VDCC involved in excitatory and inhibitory transmitter release in invertebrate neuromuscular synapses. Its distinguishing features are that opener muscle fibers are innervated by single excitatory and inhibitory axons that can be experimentally studied separately, and which release L-glutamate (Glu) and 't-aminobutyric acid (GABA) as transmitter, respectively (27,28 MATERIALS AND METHODSThe neuromuscular preparation of the opener muscle of the first walking leg of crayfish (Procambarus clarkii) was used (Fig. 1A). The muscle, which was separated at the propodite, and the nerve bundles, which include separate excitatory and inhibitory axons, were identified and isolated at the meropodite and transferred to a perfusion chamber (2 ml).

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Section: Discussionmentioning

confidence: 99%

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

Araque

Clarac

Buño

1994

Proc. Natl. Acad. Sci. U.S.A.

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“…At higher stimulation rates, the initial long-lasting EPSC barrage was followed by double, triple, or quadruple EPSCs, as described above. The higher EPSC amplitude in the presence of the venom could thus be simply due to the frequency-dependent synaptic facilitation (see Atwood, 1982;Araque et al, 1992). This mechanism could also be responsible for the higher amplitude of the subsequent extra EPSCs.…”

Section: Effects On the Excitatory Neuromuscular Junction Of Crayfishmentioning

confidence: 99%

“…This preparation has been described in detail elsewhere (Araque et al, 1992Araque and Bufio, 1994). Briefly, the opener muscle of the first walking leg of the crayfish (Procambarus clurkii) was separated at the propodite and transferred to a perfusion chamber (2 ml).…”

Section: Crayfish Neuromuscular Preparationmentioning

confidence: 99%

Selective block of Ca²⁺‐dependent K⁺ current in crayfish neuromuscular system and chromaffin cells by sea anemone Bunodosoma cangicum venom

Araque

Urbano

Červeñanský

et al. 1995

J of Neuroscience Research

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The effects of the nematocyst venom of the sea anemone Bunodosoma cangicum on depolarization‐activated currents were studied in opener crayfish muscle fibers and in cultured bovine chromaffin cells. The venom selectively and reversibly blocked the Ca2+ ‐dependent K+ current (IK(Ca)) present in crayfish muscle in a dose‐dependent manner without affecting voltage‐gated Ca2+ or K+ currents. Furthermore, the venom also reduced IK(Ca) in chromaffin cells, without modifying voltage‐gated Na+, Ca2+, or K+ currents. Synaptic transmission in crayfish muscle was also affected by the venom. Repetitive excitatory and inhibitory postsynaptic currents (each associated with a presynaptic action potential) were evoked by each nerve stimulus, suggesting that presynaptic IK(Ca) may control the electrical activity of excitatory and inhibitory presynaptic fibers. We conclude that B. cangicum venom includes a toxin that selectively and reversibly blocks Ca2+ ‐dependent K+ currents in crayfish muscle and in bovine chromaffin cells, and modifies excitatory and inhibitory synaptic transmission, probably abolishing a similar conductance at the presynaptic fibers. © 1995 Wiley‐Liss, Inc.

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Neurotoxic acylpolyamines from spider venoms

McCormick

Meinwald

1993

J Chem Ecol

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Glutamatergic postsynaptic block by Pamphobeteus spider venoms in crayfish

Cited by 10 publications

References 26 publications

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

Selective block of Ca²⁺‐dependent K⁺ current in crayfish neuromuscular system and chromaffin cells by sea anemone Bunodosoma cangicum venom

Neurotoxic acylpolyamines from spider venoms

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Glutamatergic postsynaptic block by Pamphobeteus spider venoms in crayfish

Cited by 10 publications

References 26 publications

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.

Selective block of Ca2+‐dependent K+ current in crayfish neuromuscular system and chromaffin cells by sea anemone Bunodosoma cangicum venom

Neurotoxic acylpolyamines from spider venoms

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Selective block of Ca²⁺‐dependent K⁺ current in crayfish neuromuscular system and chromaffin cells by sea anemone Bunodosoma cangicum venom