Current Views on Perineurial Cells: Unique Origin, Structure, Functions

This review aims to consolidate current views on the cells of one of the peripheral nerve sheath layers, perineurium. The relevance of the subject matter owes the lack of basic knowledge about the involvement of these cells in the restoration of damaged nerve conductors, as well as the need to unravel the molecular mechanisms that stimulate the regeneration of damaged nerves. The review summarizes recent data on the morphofunctional features of the perineurium, phylogenetic and ontogenetic origins of perineurial cells, and molecular features of the regulation of the blood–nerve barrier. It accentuates the uniqueness of the ontogenetic origin of the perineurium, characterizes immunohistochemical markers of perineurial cells, describes the features of the perineurium in the dorsal root ganglia and spinal nerve roots.