RESUMO
We studied the age-related features of spinal inhibition in the regulation of voluntary movements in males. It was found that presynaptic, nonreciprocal and reciprocal inhibition of the flexor of toes during voluntary movements was less intense as compared with relative muscle rest in all studied age groups. This results from the age-related features of supraspinalactivatory and inhibitory effects on la and Ib spinal interneurons, which change the mechanism of spinal inhibition of voluntary movements during the development of the organism. In boys aged 9-12 years, the presynaptic inhibition of Iaafferents is lowest, while the nonreciprocal and reciprocal inhibition of (αmotoneurons of the flexor of toes is highest among all studied age groups. In boys aged 14-15 years, the presynaptic inhibition of Iαafferents is higher, while the nonreciprocal and reciprocal inhibition of cxmotoneurons of the flexor of toes is lowest among the age groups. By the age of 17-18 years, the mechanism of nonreciprocal inhibition of αmotoneurons of the flexor of toes during voluntary movements is similar to that at the age of 14-15 years. The final level of presynaptic inhibition of Iαafferents and reciprocal inhibition of αmotoneurons. is reached at the age of 17-18 years.
