Measurements of neuron-specific and glia-specific proteins were used to characterize chemical-induced injury to the rat CNS. Trimethyltin (TMT), a neurotoxicant which preferentially damages neurons in limbic structures, was employed to produce consistent, time-dependent, dose-related, cell-type-specific alterations in CNS morphology. Brain weights and histology were used to verify the cytopathological effects of TMT. Accompanying changes in two synaptic vesicle-associated proteins, synapsin I and p38, and the astrocyte-associated protein, glial fibrillary acidic protein (GFAP), were measured by radioimmunoassay (RIA). Immunohistochemistry of GFAP and incorporation of 3H-thymidine into GFAP-positive astrocytes also were used to characterize astrocytic responses to TMT-induced injury. Finally, quantitative two-dimensional PAGE was employed to detect additional proteins affected by TMT. Acute administration of TMT caused large dose- and time-dependent decreases in synapsin I and p38 in hippocampus; the same proteins were largely unaffected in a non-limbic structure, the frontal cortex.