Effects of muscle electrical activity on the transmission of developing neuromuscular junction.
Miniature endplate potentials (MEPPS) caused by the spontaneous release of ACh from the growth cone of cholinergic neurons, are recorded by the whole-cell patch-clamp technique on a large number of 1-day cultured myoballs which have contact neurites of co-cultured neurons. Both muscle cell and neuron are dissociated from the 1-day-old (about stage 20) Xenopus embryo. Frequency and/or amplitude of MEPPs can obviously increase after the repetitive high-level depolarization caused by the stimuli on muscle cells. No detectable changes of single ACh receptor channel property are observed by using the single-channel recording technique. These results suggest that the mechanism of the increase of MEPPs after electrical activity of postsynaptic muscle cells probably involve some alteration of presynaptic membrane.
Tang
Y G
YG
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, PRC.
Xie
Z P
ZP
Mao
J
J
He
Z Q
ZQ
Zhao
N M
NM
D000109:Acetylcholine / Q000378:metabolism; D000200:Action Potentials; D000818:Animals; D002478:Cells, Cultured; D008564:Membrane Potentials; D009045:Motor Endplate / Q000254:growth & development / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D009435:Synaptic Transmission; D014982:Xenopus laevis
D011950:Receptors, Cholinergic; D000109:Acetylcholine