Use of Synaptoneurosome Samples to Study Development and Plasticity of Human Cortex

Translation from animal models of visual system development and plasticity to human studies is difficult due to many obstacles in comparing results. Animal models provide important data about the neurobiological mechanisms that support cortical function and behavior, but identifying the same mechanisms in human cortex can be challenging. Many neurobiological techniques used in animal models cannot be used in humans, hindering our understanding of visual system development in the human brain. Western blotting using synaptoneurosomes prepared from postmortem human tissue, however, is a simple and reliable way to study synaptic protein expression in both animal and human brains. Synaptic proteins are linked with specific aspects of visual system development and plasticity necessary to establish functional neural circuitry. Our lab has implemented a filtered synaptoneurosome preparation using human cortical tissue to study the development of human visual cortex. This approach provides human researchers with much-needed information about neurobiological development and potential targets for treatments or therapies of visual disorders that have been previously tested in animal models. The protocol detailed in this chapter provides the step-by-step information needed for making synaptoneurosomes from human postmortem brain tissue, testing and equating antibodies for Western blotting using human brain tissue, and studying the expression of synaptic proteins. We provide strengths and limitations for using synaptoneurosomes to link structure and function in the human brain. This chapter highlights Western blotting of human synaptoneurosomes as an effective tool for studying the human brain and helping to narrow the translation gap.