TNF and brain ischemia: The detrimental effects of TNF-α in cerebral ischemia have been attributed to a number of mechanisms, namely increasing the blood brain barrier permeability (Megyeri et al., 1992), stimulating the production of matrix-degrading metalloproteinase (Rosenberg, Dencoff, Correa, Reiners, & Ford, 1996), increasing leukocyte adhesion to brain vessels (Robbins et al., 1987), and direct toxic effects on brain capillaries (Goldblum & Sun, 1990).