Prenatal Sensory Stimulation Induces BDNF Gene Expression in the Brain and Potentiates the Development of Species-Specific Predisposition in Newborn Chicks.

We studied the effects of light and non-specific sound stimulation of domestic chick embryos on their filial preference as well as on the expression of two transcriptional factors c-Fos and Egr-1 and neurotrophin BDNF in the embryo brain. Prenatal light stimulation increased preference of the "natural" object, thus producing a priming effect. In the brain of E19 embryos, c-Fos and Egr-1 were expressed at a high basal level and neither light nor sound stimulation affected the number of cells expressing these factors. BDNF mRNA was also present in a number of brain areas of non-stimulated embryos, but light and sound stimulation enhanced the expression of BDNF mRNA in brain structures associated with filial imprinting. These findings suggest that BDNF is probably involved in the effects of prenatal priming on the development of species-specific behavior.