Neuroproteomics is the study of the protein complexes and species that make up the nervous system.  These proteins interact to make the neurons connect in such a way to create the intricacies that nervous system is known for.  Neuroproteomics is a complex field that has a long way to go in terms of profiling the entire neuronal proteome.  It is a relatively recent field that has many applications in therapy and science.
So far, only small subsets of the neuronal proteome have been mapped, and then only when applied to the proteins involved in the synapse.