Quantitative evaluation of the function of the presynaptic apparatus of the rat in cold adaptation

: Binomial parameters of transmitter secretion were calculated on the basis of synaptic potential analysis for the diaphragm and extensor digitorum longus muscles of the control and cold-adapted rats. The quantum content, amplitude of EPPs and the amount of available transmitter increased in these muscles of cold-adapted rats. This may be due to the influences of neurohumoral factors on the presynapse or, on the other hand, to changes in metabolism of the nerve terminal. Differences in presynaptic characteristics of the muscles between the control and the cold-adapted rats indicate the high reliability of the neuro-muscular junction functioning during slow rhythmic stimulation in cold ambient condition and the identical processes in the nerve terminal in the two groups of muscles.