Role of α7 Nicotinic Acetylcholine Receptors in Synaptic Transmission in Frog Neuromuscular Contacts.

The role of α7 nicotinic acetylcholine receptors in coupling of synaptic activity and muscle contractions was studied in frog (Rana ridibunda) neuromuscular synapses. The amplitude of endplate currents, the probability of action potential generation, and the strength of muscle contractions decreased in the presence of selective α7 antagonist methyllycaconitine. The effects of nicotinic acetylcholine receptor blockade depended on the pattern of the motor nerve stimulation. It can be assumed that the muscle action potential is a factor of retrograde control of neurosecretion, which modulates activity of α7 nicotinic receptors and the release of acetylcholine from motor nerve endings.