Cerebellum been identified as important: (1) feedforward processing, (2) divergence and convergence, (3) modularity, and (4) plasticity. There is considerable evidence that the cerebellum plays an essential role in some types of motor learning. The tasks where the cerebellum most clearly comes into play are those in which it is necessary to make fine adjustments to the way an action is performed. There has, however, been much dispute about whether learning takes place within the cerebellum itself, or whether it merely serves to provide signals that promote learning in other brain structures. Most theories that assign learning to the circuitry of
Antigen transfer in the thymus in thymic medulla, namely clonal deletion ("recessive tolerance") and T Regulatory cells selection ("dominant tolerance") which force autoreactive T cells to apoptosis or skew them into suppressor T regulatory cells (TRegs), respectively, in order to protect body against manifestations of autoimmunity. These processes are mediated especially by unique subset of stromal cells called Medullary thymic epithelial cells (mTECs) via presentation of Tissue restricted antigens (TRAs) that represent self tissues from almost all parts of the body. mTECs are not only capable to present TRAs as efficient APCs. They are also potent in production of these TRAs via unique process called