Effect of social factors on the development of PKC expression in songbird brain.

Vocal learning by songbirds is affected by a song template and social factors. Normal male zebra finches with a song template and social interactions with other birds showed a transient increase of protein kinase C (PKC)-like immunoreactivity in the song control nuclei during a sensitive period of song learning. However, auditory isolation, which prevents the development of a song template induced an abnormal PKC development, which depended on the social interactions with other birds. In conclusion, social experience during an early sensitive period of song learning in the zebra finch is essential for the normal development of PKC expression in the robust nucleus of the arcopallium (RA), a premotor nucleus related to vocal plasticity.