HISTOLOGY OF NERVOUS TISSUE AND POSSIBILITIES OF REGENERATION

Abstract

Nervous tissue is considered the most complex and specialized tissue in the human and animal body. It is composed of nerve cells — neurons — and the supporting glial cells. Nervous tissue forms the central nervous system (the brain and spinal cord) as well as the peripheral nervous system (peripheral nerves and ganglia).The primary function of nervous tissue is to receive information from the external and internal environment, transmit it, and generate appropriate responses. The morphological structure of this tissue, its organization at the cellular and tissue levels, and its functional roles in physiological processes are of great significance.

The regeneration of nervous tissue — that is, its ability to recover after damage — is one of the most important fields in modern neurobiology. The regenerative potential of the central nervous system (CNS) is significantly lower than that of the peripheral nervous system (PNS). This means that complete recovery after brain or spinal cord injuries is very unlikely. In contrast, the peripheral nervous system has a relatively high capacity for regeneration, largely due to the activity of Schwann cells.

This difference is mainly determined by the internal microenvironment of the tissue, as well as the presence of factors that either stimulate or inhibit regeneration.

Recent studies have demonstrated that, although limited, neurogenesis — the formation of new neurons — does occur within the central nervous system (CNS). In particular, it has been identified that in adults, neuroblasts form in the hippocampus and in the subventricular zones surrounding the lateral ventricles. This indicates that nervous tissue possesses a certain ability to regenerate under specific conditions. However, such processes are extremely slow and rarely result in complete recovery.

Glial cells, especially astrocytes, play a significant role in this context. Following injury, they proliferate and form glial scars (gliosis), which represent one of the major obstacles to CNS regeneration. These glial scars restrict the transmission of nerve impulses and create both physical and chemical barriers for regenerating axons. Therefore, a substantial portion of modern research is devoted to overcoming these barriers, identifying biomolecules that stimulate regeneration, and accelerating neuronal recovery through neurotrophic factors.

This article analyzes the histological structure of nervous tissue, the interaction between neurons and glial cells, the mechanisms of regeneration, and the differences between the regenerative capacities of the CNS and PNS. Moreover, contemporary therapeutic approaches and treatment strategies — including neurostimulation, biomaterials, and stem cell therapy — are discussed. Both experimental and clinical studies addressing the challenges and achievements in nervous tissue regeneration are reviewed.

A deeper understanding of the regenerative potential of nervous tissue will not only contribute to solving problems in surgery, traumatology, and neurology, but will also lay the foundation for future advances in the treatment of neurodegenerative diseases.