[Interneurons Brainstem of the Human]

To conduct a comparative study of the structural organization of internuclear interneurons involved in the metabolism of nitrogen monoxide, hydrogen sulphide and carbon monoxide in the caudal brain stem humans.

The cross-sectional study was performed. We used histochemical and immunohistochemical methods to study the internuclear interneurons expressing neuronal nitric oxide synthase, cystathionine β-synthase and heme oxygenase-2 which are located between the giant and small cell reticular nuclei (cell group 1), small cell reticular nucleus and the nucleus of the solitary tract (cell group 2) or is surrounded by reticular lateral nucleus (cell group 3).

The work was carried out on the corpses of 6 men 18-44 years old who died from causes unrelated to the damage of the central nervous system. We revealed the differences between internuclear organization and intranuclear interneurons and local structural features of internuclear interneurons that are more clearly visible between the cell group 1 including a relatively large number of large neurons and cell groups 2 and 3 (p < 0.001). In the latter two groups small cells with high concentrations of the neuronal nitric oxide synthase and heme oxygenase-2 dominated.

Despite the fact that the number of internuclear interneurons significantly is less than the number of intranuclear cells, they have structural prerequisites to control integration processes in the brain. Internuclear interneurons produce gasotransmitters and classical mediators of nerve impulse, form a local chain of interneurons between vasomotor nuclei, share many links with the above and the lower parts of the brain.