Ultrastructural identification of telocytes in the muscularis of chicken ileum

Telocytes (TCs) are a specialized type of interstitial cells, characterized by a small cell body and long, thin processes, that have recently been identified in various cavitary and non-cavitary organs of humans and laboratory mammals. Chickens present significant economical and scientific notability; however, ultrastructural identification of TCs remains unclear in birds. The aim of the present study was to describe electron microscopic evidence for the presence of TCs in the chicken gut. The ileum of healthy adult broiler chickens (n=10) was studied by transmission electron microscopy. TCs are characterized by several, long (tens to hundreds of µm) prolongations called telopodes (Tps). Tps, which are below the resolving power of light microscopy, display podomeres (thin segments of ≤0.2 µm) and podoms (dilations accommodating caveolae, mitochondria and endoplasmic reticulum). TCs were observed in every field, but were predominantly located in the myenteric plexus and the lamina propria. Tps frequently establish close spatial relationships with immune cells, blood vessels and nerve endings. On the basis of their distribution and morphology, it was hypothesized that the different locations of TCs may be associated with different roles.