Mechanism of betabungarotoxin in the facilitation of spontaneous transmitter release at developing n

1
Mechanism of beta-bungarotoxin in the
facilitation of spontaneous transmitter release
at developing neuromuscular synapse
Authors name Here  Department of Biological
Sciences, National Sun Yat-sen University,
Kaohsiung, Taiwan
Figure 1
Figure 3
Mechanisms of b-BuTx-induced synaptic
facilitation in Xenopus nervemuscle cultures
Cultures were pretreated with various inhibitors
and the effect of b-BuTx on SSC frequency was
evaluated
Effect of b-BuTx on the spontaneous ACh quantal
release at Xenopus neuromuscular synapse.A,
Downward events are inward spontaneous synaptic
currents (SSCs) resulting from quantal ACh
secretion. B, Changes in the SSC frequency with
time after the addition of b-BuTx C,
Concentration-response relationship of b-BuTx in
the facilitation of SSC frequency.
Figure 4
Figure 2
Role of PLA2 activity in b-BuTx-induced SSC
frequency facilitation. Glycyrrhizin ARIST,
PLA2 inhibitor non-neurotoxic pancreatic PLA2,
indomethacin, cyclooxygenase inhibitor NDGA,
lipoxygenase inhibitor
b-BuTx elicits Ca2 release from IP3 sensitive
intracellular Ca2 stores of the presynaptic
nerve terminal. This is done via PI3K/PLCg
signaling cascades and G protein activation,
leading to an enhancement of spontaneous
transmitter release.
Dependence of b-BuTx effect on Ca2 mobilization
from internal Ca2 stores. Summary of the change
of b-BuTx-induced SSC frequency facilitation in
the presence of various drugs.