ABSTRACT
Injury of any tissue gives rise to an immediate inflammatory response and it is probable that this initial response is primarily aimed at priming the process of repair. The nature of the nervous system is such that its integrity needs to be strongly preserved. The blood-brain barrier restricts the entry of solute and is essential for the normal functioning of the central nervous system (CNS); a similar barrier is a general feature of the nervous system of invertebrates as well as vertebrates and of peripheral nerves as well as the CNS. To elicit an immune response, antigen must be able to leave the brain, either directly or following endocytosis by a predendritic cell, and arrive at a lymphoid organ. The dendritic cell is probably the major component of the innate immune system, providing a connection with the adaptive immune response.
