The effects of glutamate and GABA (gamma-amino-butyric-acid) on spontaneous acetylcholine release at the neuromuscular junction in Xenopus laevis embryo cell cultures.
The miniature endplate currents (MEPC's) were recorded at the neuromuscular junction of Xenopus laevis embryo neuron-muscle co-cultured cells. These MEPC's were due to the spontaneous release of acetylcholine from the nerve terminal. After perfusion with glutamate (10 mumol/L), both frequency and amplitude of the MEPC's increased. After washing away of glutamate, this effect persisted. We named this phenomena "Long-Term Facilitation". GABA (20 mumol/L) on the other hand had an inhibitory effect on both frequency and amplitude of the MEPC's. After washing away of GABA, the MEPC frequency and amplitude increased. We named this effect "Post-Potentiation". Local perfusion experiments furthermore indicated that the effect of glutamate was restricted to the neuromuscular junction, the effect of GABA was restricted to the soma.
Xie
Z P
ZP
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, PRC.
Tang
Y G
YG
Stoop
R
R
Mao
J
J
Zhao
N M
NM
Lü
G N
GN
Yang
S R
SR
He
X P
XP
Wang
H
H
Liu
C G
CG
D000109:Acetylcholine / Q000378:metabolism*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002478:Cells, Cultured; D005971:Glutamates / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000502:physiology; D009469:Neuromuscular Junction / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005971:Glutamates; D005680:gamma-Aminobutyric Acid; D000109:Acetylcholine