FOXG1 Hierarchically Shapes Synaptic Functions in Striatal iSPNs and Contributes to ASD Etiology

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Striatal dysfunction is implicated in autism spectrum disorder (ASD) pathophysiology.
• Forkhead box G1 (FOXG1) syndrome shares core features with ASD, suggesting a link.
• The precise mechanisms of FOXG1's role in neuronal function and ASD remain unclear.

Purpose of the Study:

• To investigate the role of FOXG1 in indirect pathway spiny projection neurons (iSPNs) in the context of ASD.
• To elucidate the molecular mechanisms by which FOXG1 regulates synaptic function.
• To explore potential therapeutic targets for ASD and FOXG1 syndrome.

Main Methods:

• Utilized a mouse model with Foxg1 loss specifically in iSPNs.
• Assessed behavioral phenotypes including social interaction, language, and fine motor skills.
• Performed electrophysiological recordings and dendritic analyses to evaluate synaptic function.
• Conducted transcriptome analysis to identify FOXG1-regulated gene networks.
• Investigated the effect of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) potentiation.

Main Results:

• Loss of Foxg1 in iSPNs recapitulated ASD-like behaviors and deficits in dendritic complexity and synaptic transmission.
• FOXG1 regulates extensive gene networks controlling synaptic development, maturation, and function.
• FOXG1 directly drives the expression of AMPAR subunits.
• Pharmacological potentiation of AMPAR activity normalized synaptic function and rescued behavioral deficits.

Conclusions:

• FOXG1 is crucial for normal synaptic development and function in iSPNs, and its deficiency contributes to ASD etiology.
• Dysregulation of AMPARs is a key consequence of Foxg1 deficiency.
• Targeting AMPAR activity presents a promising therapeutic strategy for ASD and FOXG1 syndrome.