Auditory stimulus-induced changes in immediate-early gene expression related to an inborn perceptual predisposition

Auditory-induced expression of the immediate-early gene ZENK was examined in 18 brain areas of domestic chicken and Japanese quail subjects with no previous exposure to parental vocalizations. After one 30-min exposure (approximately 120 calls) within 24 h of hatching to either the chicken or quail maternal call, paired subjects from each species showed significantly more intense levels of ZENK staining to conspecific (own species) calls. Single brain areas did not show consistent, large differences in ZENK expression across all subject pairs. Instead, a majority of brain areas exhibited a small conspecific stimulus-induced staining advantage in each species. The species differed in the quantitative distribution of ZENK responses among brain areas; qualitative patterns of call-induced staining exhibited both similarities and differences. The results suggest shared neural correlates and potential developmental/evolutionary differences in congenital brain responses to biologically significant auditory stimuli in naïve individuals of the two species.