Возрастные изменения морфо-функциональных характеристик мотонейронов белой крысы

Abstract

Abstract Background: Proteins neurofilaments (NF) are a family of intermediate filaments, the most common structure of the cytoskeleton of neurons with large sizes and long myelinated axons, participate in the development and maintenance of normal diameter axons, provide optimal speed of axonal conduction is transferred from the cell body to the end of the slow axon transport and consist of three polypeptide subunits, which differ in molecular weight: light – 68-73 kDa (NFL), medium – 140-160 kDa (NFM), heavy – 195-200 kDa (NFH).The breach in the structure of each protein neurofilaments can change the structure of the whole complex of the cytoskeleton of axons and thereby affect the functioning of both the axon and the neuron as a whole. Material and methods: Morphometric characteristics of neurons containing protein neurofilaments with weight of 200 kDa was studied on transverse cryostat sections with a thickness of 14 μm T2 spinal cord (SC) in 3, 10, 20, 30, 60, 90, 180, 360-day-old Wistar rats immunohistochemical and histological methods. Topographical characteristics of motor neurons was studied in slices in the ventral horn of the SС by setting their respective IX lamina of Rexed, the number and cross-sectional area of motor neurons. Results: The motoneurons containing protein neurofilaments NFH detected in T2 SC with 3-day-old rats and presents in the ventromedial and dorsolateral groups of neurons localized in the lamina IX and correspond to large neurons. The number of motoneurons with NFH in both topographic groups decreases during the first year of life rats with peak reduction at 10-day-old. The average cross-sectional area of the motoneurons in both topographic groups increases during the life of the rat, the maximum growth rate is in 10-day-old. Dimensions are ventromedial motoneurons more, than dorsolateral in the first month of life, after that age differences are leveled out. Conclusions: The critical period is the 10-day-old rats for the formation of immunoreactivity to NFH in motoneurons SC, that is evident not only quantitative but also qualitative neuronal structural rearrangements.