Exogenous testosterone alters expression pattern of cell recognition molecules in brains of juvenile zebra finches

We assessed spatio-temporal expression of tenascin and janusin by immunocytochemistry in testosterone-treated zebra finches and in untreated controls. These cell recognition molecules and components of the extracellular matrix mediate neuroneglia interactions, which are crucial for differentiation of ordered neural structures. We describe boundaries for the spatio-temporal expression of cell recognition molecules that highly correlate with the song motor centres as defined by combined neuroanatom- ical and ethological studies on song vocalization. The expression of janusin is accelerated by exogenous testosterone.