Structural and Histochemical Changes in Rat Parietal Cortex Neurons during Biliary Drainage

Abstract

The aim of the study reported here was to assess structural and metabolic changes in rat parietal cortex neurons during complete external bile drainage. Quantitative histochemical and electron microscopic methods were used. The findings showed that drainage of bile from the body led to gradual increases in the numbers of hyperchromic pyknotic neurons and ghost cells, death and reductions in the numbers of neurons, and increases in the number of glial cells in all layers of the parietal cortex. There was a gradual decrease in neuron size, with loss of sphericity (elongation). The cytoplasm showed decreases in succinate dehydrogenase, NADH, NADPH, and glucose-6-phosphate dehydrogenases, and decreases in RNA content, though these changes were accompanied by activation of lactate dehydrogenase and acid phosphatase. Nuclei and organelles (mitochondria, endoplasmic reticulum, Golgi complexes) underwent destructive changes, which were accompanied by increase in the numbers and sizes of lysosomes and phagosomes. Some neurons showed activation of the nuclear apparatus and increases in the relative content of free ribosomes. Thus, loss of bile from the body induced progressive increases in structural and metabolic changes in parietal cortex neurons, leading to the death of some and compensatory changes in others.