The intercellular contact between a motor neuron and a skeletal muscle fiber is one of the general models for electrophysiological studies of the mechanisms underlying the functioning of a chemical synapse. At the same time, there is very little data on the features of the process of neuromuscular synaptic transmission in animals at the early stages of postnatal development, and no systematic study of changes in electrophysiological parameters in ontogenesis has been conducted. Using a relatively recently proposed model, namely, a neuromuscular preparation of m. levator auris longus of a mouse, and the classical method of dissection of muscle fibers (to block contractions), we have for the first time carried out a detailed analysis of the most commonly used electrophysiological parameters characterizing the processes of spontaneous and evoked quantal release of acetylcholine from motor nerve endings: amplitude-temporal parameters of spontaneous and evoked end plate potentials, frequency of miniature potentials, quantal content and latency of evoked responses. The dynamics of changes in the recorded parameters throughout the entire life of a mouse is demonstrated. Particularly striking changes were detected in the first days after birth, but, as it turned out, neuromuscular signaling in two-week-old animals still differs significantly in a number of parameters from what occurs in the synapse of an adult organism. The data obtained can be used in the future to study the ontogenetic features of various neuroregulatory processes.
Nevsky et al. (2025) studied this question.