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

Abstract

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 ttest. 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 cm2 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.Uvod/Cilj. Starenje je jedan od bioloskih procesa koji verovatno utice na strukturu i funkciju enterickog nervnog sistema. Medjutim, veoma je malo informacija o ovoj temi, posebno kada je u pitanju ljudska vrsta. Cilj ove studije bio je istrazivanje uticaja starenja na strukturu mijenterickih ganglija proksimalnog dela humanog duodenuma. Metode. Ispitivan je mijentericki nervni splet prednjeg zida proksimalnog dela duodenuma uzoraka uzetih od 30 kadavera osoba starih od 20 do 84 godine. Uzorci tkiva proksimalnog dela duodenuma prema starosti bili su razvrstani u tri grupe: od 20 do 44 godine, od 45 do 64 i od 65 do 84 godine. Nakon standardne histoloske obrade preparati su bojeni hematoksilin-eozin (HE), Cresyl violet i AgNO3 metodom bojenja. Gotovi preparati bili su podvrgnuti morfometrijskoj analizi koriscenjem visenamenskog sistema za testiranje M42. Dobijeni rezultati obradjivani su t-test. Rezultati. Mijentericke ganglije veoma starih osoba sadrze prazne prostore, odnosno pojedini delovi ganglija pokazuju deficit broja neurona u odnosu na mladju populaciju. Prosecan broj neurona/cm2 duodenuma kod najmladjih (20-44 godine) iznosio je 69 370 ? 1 750, kod osoba starosti 45-64 godine 69 211 ? 1 573,33, a kod najstarijih (65-84 godine) 57 951 ? 1 291,52. Procentualni gubitak neurona kod najstarijih iznosio je 16,46%. Primenjeni statisticki test ukazuje na postojanje znacajnih razlika izmedju starosnih grupa (p < 0,0001). Zakljucak. Tokom starenja ne dolazi do promena velicine gangliona, ni povrsine neurona, vec do gubitka broja neurona. Ganglijske strukture kod starijih osoba delimicno su ispraznjene od tela nervnih celija (?prazni ganglioni?), sto ukazuje na postojanje izmenjenih mijenterickih ganglija u duodenumu. To najverovatnije doprinosi poremecaju motiliteta duodenuma kod starije populacije.