Age-related structural changes in the myenteric nervous plexus ganglion along the anterior wall of the proximal human duodenum - a morphometric analysis

Background/Aim. Aging is one of the most complex biological processes which probably affect structure and function of the enteric nerve system. However, there is not much available information on this topic, particularly in humans. The aim of this study was to investigate the influence of aging on the structure of the myenteric ganglia in the anterior wall of the human proximal duodenum. Methods. We examined the myenteric ganglia in the proximal duodenal anterior wall specimens obtained from 30 cadaver persons aged from 20 to 84 years. Tissue samples were classified into three age groups: 20-44, 45-64 and 65-84 years. After standard histological preparation, specimens were stained with HE, Cresyl Violet and AgNO3. Morphometric analysis of all the specimens, using a multipurpose test system M42, was performed. The data were subjected to the t-test. Results. The myenteric ganglia of very old humans contains an empty space, i.e. the respective parts of ganglia show a decreased number of neuron as compared to younger population. The average number of neuron per cm(2) of the duodenum in the youngest people (20-44 years) was 69,370 +/- 1,750.00, in the people aged 45-64 years 69,211 +/- 1,573.33, and in the oldest persons (65-84 years) 57,951 +/- 1,291.52. The loss of neurons in the oldest persons was 16.46%. The applied statistic test demonstrated a significant difference between the observed groups (p < 0.0001). Conclusion. Aging does not induce changes in size and surface of neurons in the ganglia, but it decreases the number of neurons. The nerve structures in the elderly are partly emptied of bodies of nerve cells ("empty ganglions"), which indicates the existence of changed myenteric ganglia in the duodenum. These changes could be related to the duodenum motility disorder associated with aging.