[The early postdenervation changes in the properties of the postsynaptic membrane of amphibian muscle fiber].
The amplitude-temporal characteristics of miniature end-plate currents (MEPC) were studied in denervated frog cutaneous-pectoral muscles. After the nerve cutting, the initial shortening of MEPC decay time was followed by its prolongation. In 6-8 days after the denervation, the MEPC sensitivity to membrane potential decreased, while the average open time of ACh-activated channels increased 2-fold. The autocorrelation function of ACh-induced current noise revealed two components at some of the synapses. The denervation of the frog cutaneous-pectoral muscle seems to make the postsynaptic membrane to contain two types of ACh receptors (AChR): normal synaptic AChR which gradually disappear, and new synthesized AChRs which open the channels with much longer mean time and a lesser sensitivity to membrane potential changes.
Zemskova
S N
SN
Eder
K
K
Giniatullin
R A
RA
Zefirov
A L
AL
Khazipov
R N
RN
D000109:Acetylcholine / Q000037:antagonists & inhibitors / Q000502:physiology; D000818:Animals; D001138:Armin / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009045:Motor Endplate / Q000187:drug effects / Q000502:physiology; D009121:Muscle Denervation; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D011898:Ranidae; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000502:physiology; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D011950:Receptors, Cholinergic; D017981:Receptors, Neurotransmitter; D001138:Armin; D000109:Acetylcholine
Rannie postdenervatsionnye izmeneniia svoĭstv postsinapticheskoĭ membrany myshechnogo volokna amfibiĭ.