Histological structure of midbrain red nucleus in albino rats at different ages

This study was conducted on twelve healthy male albino rats to investigate the histological structure of the midbrain red nucleus at different ages and to correlate these changes using light and electron microscopic preparations. The animals were classified into three groups: neonates (early and late), adult and senile. Upon sacrifaction,midbrain samples were prepared for light microscope (L/M) examination using haematoxylene, eosin and silver stains. Other minute parts were processed for transmission electron microscopic examination.In this study, L/M examination revealed that the nerve cells of red nucleus were relatively small at the age of 7th and 21st days and became relatively larger at the age of 4 months of life, followed by reduction again occurring at senility. In the 7th days of life there was a morphological maturation affecting the nerve cells of the red nucleus was noticed by electron microscopic examination in the form of appearance of synapses. Each neuron contained a nucleus,which varied from eccentric to central position. Nuclei were usually indented and the cytoplasm contained prominent mitochondria, Golgi apparatus and rough endoplasmic reticulum. The neuronal cell membrane was regular. Growth cone could be detected, which had been seen at 7th and 21st days of life. At senile group the small nerve cells were detected in section of red nucleus in the form of darkly stained cytoplasm, ill-defined dark nucleus and irregular shape of nerve cell and marked reduction in all the constituents of the cytoplasm. The same findings were also confirmed by studying the semithin section. In conclusion, the previously observed histological alterations could explain the age related changes affecting the red nucleus, therefore it wasn’t surprising to find different locomotor’s impactions occurred with aging.