This is an NIH Pathway to Independence Award, which provides an opportunity for promising postdoctoral scientists to transition from mentored to independent research support. Impaired cognition, and in particular language, is a hallmark of common neuropsychiatric disorders such as autism and schizophrenia; however, the molecular mechanisms underlying higher cognitive function development and evolution in humans remain unknown. Frontal-striatal circuitry is critical for normal cognitive function and is frequently disrupted in neuropsychiatric disease. The transcription factor FOXP2 is the only gene currently identified that is mutated in patients with isolated language disturbances, and it has high expression in both frontal and striatal regions of developing human brain. Current data supports a role for both FOXP2 and its regulation of genes involved in autism and schizophrenia. This research will focus on the developmentally regulated signaling pathways downstream of FOXP2 and how perturbations to these pathways result in cognitive defects in both ASD and schizophrenia. Specifically, the project will: 1) Identify the signaling pathways regulated by FOXP2 in human neurons, and which of these pathways are important for neuronal differentiation and/or maintenance, 2) Determine evolutionarily conserved and human-specific FOXP2 targets by conducting comparative whole gene transcriptome sequencing and FOXP2 promoter binding in fetal human, rhesus macaque, and mouse brain, and 3) Ascertain how Foxp2 and Foxp1 cooperatively regulate gene expression during CNS development by generating Foxp1 conditional knockout mice and conducting genome wide Foxp2 promoter binding analysis. The elucidation of signaling pathways that are important for language and cognition will provide targets for future therapeutics.