The idea that the brain is an "immune-privileged site" has perhaps served to slow our realization that the intact brain can generate its own inflammatory reactions. These responses can be to peripheral infection, or they can arise from local, internal causes, for instance as a response to stress or to the se vere changes in neuronal activity in seizure or the loss of oxygen in stroke. We are also becoming increasingly aware of the contribution of local inflam matory reactions to certain neurodegenerative diseases such as Alzheimer's In fact, evidence is accumulating that inflammatory...