Foxp1 in Forebrain Pyramidal Neurons Controls Gene Expression Required for Spatial Learning and Synaptic Plasticity.

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Genetic mutations in the transcription factor Forkhead Box P1 (FOXP1) are linked to autism spectrum disorder (ASD) and intellectual disability (ID).
• The precise brain-region-specific roles of FOXP1 in these neurodevelopmental disorders remain incompletely understood.

Purpose of the Study:

• To investigate the impact of Foxp1 loss in specific brain regions on behaviors relevant to ASD and ID.
• To identify the molecular and physiological mechanisms underlying these behavioral changes.

Main Methods:

• Generation of Foxp1 conditional knock-out (Foxp1 cKO) mice lacking Foxp1 in neocortical and hippocampal neurons.
• Behavioral testing for ASD- and ID-relevant phenotypes (e.g., hyperactivity, anxiety, sociability, learning, memory).
• Genome-wide gene expression analysis, magnetic resonance imaging (MRI), and electrophysiological recordings (LTP).

Main Results:

• Foxp1 cKO mice exhibited hyperactivity, anxiety, impaired communication, and reduced sociability, consistent with ASD phenotypes.
• These mice showed significant deficits in learning and memory tasks relevant to ID.
• Reduced hippocampal and subfield volumes were observed in Foxp1 cKO mice via MRI.
• Downregulation of genes involved in synaptic function and development was identified in the hippocampus.
• Impaired long-term potentiation (LTP) maintenance was found in the CA1 region of the hippocampus.

Conclusions:

• Foxp1 expression in forebrain pyramidal neurons is critical for regulating gene expression pathways underlying behaviors associated with ASD and ID.
• Foxp1 plays a crucial role in normal hippocampal development, synaptic plasticity (LTP), and spatial learning.
• Brain-region-specific functions of FOXP1 may contribute to distinct clinical phenotypes observed in patients with FOXP1 mutations.