Immunocytochemical methods were used to study the regional and cellular distribution of diazepam binding inhibitor (DBI)-, ODN (DBI 33-50)- and TTN (DBI 17-50)-like immunoreactivity (LI) in monkey brain. DBI-, ODN- and TTN-LI were found to have similar regional but different cellular distributions. The most intense staining was detected in limbic structures, especially the amygdala. The most notable staining discrepancy was the weak-to-moderate uniform DBI-LI and the very high patchy ODN-LI and TTN-LI in the ventral striatum. At the cellular level, DBI-LI was preferentially localized in glia-like cells, whereas ODN-LI and TTN-LI were mainly found in neurons.