Abstract
The mechanical forces imparted on brain tissue during trauma trigger changes in proteins, membranes, DNA, and mRNA expression patterns of many different cell types, such as neurons, astrocytes, microglia, and oligodendrocytes. Biochemical and molecular biological assessments have thus become powerful, important tools for yielding significant insights into the pathomechanisms of traumatic brain injury (TBI). Using Western blotting and enzyme-linked immunosorbent assays (ELISAs), assessment of changes in proteins in large areas of tissue can identify inflammatory signaling, dysfunction in synaptic signaling, and endogenous reparative strategies. Using quantitative RT-PCR, changes in DNA and mRNA expression patterns can be identified, providing additional understanding into how areas of the brain are responding after TBI. In situ hybridization and immunohistochemistry can further refine our understanding by identifying the cell types and brain regions affected. Through such biochemical and molecular biological assessments, we can understand the mechanisms that create pathology in the brain, and potentially develop therapeutic strategies to target these molecules and improve outcome after TBI. In this chapter, we outline the steps required to analyze brain-injured tissue at the protein level by ELISA, Western blotting, and immunohistochemistry.