Protocol for the immunoprecipitation (IP) of Homer 1a, injection of virions and in situ hybridization in the spinal cord. Includes: Immunoprecipitation (IP) of Homer1a from spinal cord; Injection of virions in the parenchyma of the spinal dorsal horn in vivo; Generation of cRNA probes; Analysis of DIG-dUTP incorporation; Tissue hybridization.