Fig. 1.

Zebra finch juveniles hearing song during a known sensitive period for the formation of the memory of conspecific tutor song (posthatch day 30) exhibit a significant increase in the mTOR signaling pathway in auditory areas critical for song memory formation related to song development. This increase does not occur in an adjacent auditory area, Field L, which is involved in general auditory processing. The increase is noted by the dark shading in the CMM and NCM. Males hearing silence do not exhibit this increase. In addition, juvenile females who do not go on to develop species-typical song do not exhibit this increase during the same time of development. Neither males nor females hearing song at an earlier age (posthatch day 23) exhibit any induction of the mTOR signaling pathway in response to song at this time (result not illustrated in this figure). Ahmadiantehrani and London (6) in subsequent experiments manipulated the expression of mTOR and found significant effects to song tutor copying (see text for more detail). Cb, cerebellum; D, dorsal; Hp, hippocampus; P, posterior.