Viral Vectors to Study Synaptic Function

Neurons display strong plasticity of their cellular properties, especially by modulation of their synaptic inputs. The development of viral vectors as biological tools has been extremely useful to molecularly manipulate protein expression in the rodent brain for a better understanding of the molecular mechanisms governing such synaptic plasticity. The use of viruses has several advantages. First, it allows for expression of a protein of interest in a temporally and spatially restricted manner. Second, it allows for a direct comparison of cellular properties between neurons expressing the protein of interest and neighboring control neurons from the same animal. Finally, when these viral vectors are used in vivo, the neurons expressing the virally encoded recombinant proteins are allowed to do so while remaining in their physiological environment in freely behaving animals. In this chapter, we describe how these viral vectors can be used to study synaptic function. As an example, we focus on the use of sindbis viruses to express mutant proteins in the rat hippocampus in vivo for investigation of their role in synaptic function.