Neurotensin has also been implicated in learning processes. A study examining song development in male zebra finches showed variations in neurotensin and neurotensin receptor gene expression across different stages of song development. The early stage of transition between sensory and sensorimotor periods was marked by decreases in both neurotensin and neurotensin receptor mRNA expression, which may indicate a role of neurotensin in initiating sensorimotor learning. During the sensorimotor subsong stage, neurotensin gene expression and neurotensin receptor 1 (Ntsr1) gene expression exhibited complementary expression patterns in song-related brain regions, which may indicate changes in neuronal responses to neurotensin across development.