The paper presents the study of metric characteristics of human trigeminal ganglion neurocytes at 12-23 weeks of intrauterine growth, based on conventional histological and morphometric techniques. It has been found that at 12-14 weeks of intrauterine growth neurocytes, arranged relatively evenly, occupy a major part of the internal space of the trigeminal ganglion. During the period of study, the average diameter of neurocytes was 15,21±1,43 mcm with predominant number of small cells (54,4%). Medium-sized cells (36,6%) were detected much more rarely. The relative number of large neurocytes was — 9%. The average diameter of the smallest and largest nerve cells was within 8-9 mcm and 25-26 mcm, respectively. The latter, without some apparent regularity, were arranged in a clustered order among small and medium-sized neurons. At 16-18 weeks of intrauterine growth, a significant enlargement of the average diameter of neurocytes in trigeminal ganglion was noted, accounting for 17,15±0,36 mcm. Small neurons accounted for 16,4% of the whole cell population. The relative number of medium-sized nerve cells was 70,8%. During this period large neurons accounted for 12,8% of the total amount. In the experimental group the average diameter of the smallest and largest neurons accounted for 10-11 mcm and 27-28 mcm, respectively. Morphological characteristics of neurons of different classes were almost similar to those from the previous group. At this stage of intrauterine growth, neurocytes, in most observations, were arranged in the form of relatively isolated groups, separated by fibrillar fascicles. At 20-23 weeks of intrauterine growth, further enlargement of the average diameter of the neurons of the trigeminal ganglion were observed, accounting for 18,92±0,22 mcm. A significant decrease in the relative amount of small and medium-sized neurocytes has been noted, accounting for 10,6% and 56%, respectively. At the same time, a significant increase in large nerve cells (33.4%) was found, as compared to the previous period of fetogenesis. In the experimental group the average diameter of the smallest and largest neurons accounted for 10-12 mcm and 28-30, respectively. It should be noted that, in most observations, the largest neurocytes were arranged in the peripheral sections of the ganglion, occupying the subcapsular position. In addition, at the abovementioned period of intrauterine growth, a division of neurons into separate groups became more pronounced due to proliferation of fibrillar structures and connective tissue component, resulting in significant decrease in compactness of nerve cell arrangement.
«Bulletin of problems biology and medicine» Issue 2 part 1 (128), 2016 year, 368-371 pages, index UDK 611.831+611.018.81/.82
