Immunohistochemical localization of a 40-kDa catecholamine regulated protein in the nigrostriatal pathway

The 40 kDa catecholamine regulated protein (CRP40) has been shown to covalently bind catcholamines in vitro. In this report we provide evidence for CRP40 localization in the dopaminergic nigrostriatal pathway. Using double labeling immunohistochemistry, CRP40 was detected in the majority of substantia nigra pars compacta and striatal neurons. In addition, CRP40 was also present in tyrosine hydroxylase immunonegative neurons. Subcellular localization of CRP40 shows a predominant nuclear presence in striatal neurons while distinct outlining of the nucleus and cell body staining were seen more readily in nigral neurons. These findings suggest that CRP40 may have multiple functions in a variety of neurons in the central nervous system.