Role of Capsaicin-Sensitive Neurons in the Regulation of Structural Organization of the Thymus

Anatomical organization of the thymus was studied in adult Wistar rats after injection of a neurotoxic dose of capsaicin. The reaction of the lymphoid parenchyma attested to depletion of structural reserves and triggering of autoimmunization mechanisms and was associated with accumulation thymocytes with morphological signs of apoptosis, Hassal's bodies, macrophages, plasmacytes, and eosinophils in the subcapsular zone. Through neurokinin and vanilloid receptors on the sensory terminals and lymphocytes, capsaicin modulated the level of neuropeptides, which seemed to be involved in the regulation of autoimmune mechanisms.