Genetic Rescue of Disrupted Synaptic Protein Interaction Network Dynamics Following SYNGAP1 Reactivation

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Synaptic protein interaction networks (PINs) are crucial for neural function and plasticity.
• Disruptions in these networks are linked to autism spectrum disorder (ASD) risk genes.
• It is unknown if perturbed molecular networks can be restored after early development.

Purpose of the Study:

• To investigate the effects of post-developmental SynGAP1 re-expression on synaptic network structure and signaling.
• To determine if molecular restoration is possible even after critical developmental periods.

Main Methods:

• Utilized a conditional SynGAP1 haploinsufficient mouse model.
• Employed quantitative multiplex co-immunoprecipitation (QMI) to analyze protein interactions across development.
• Administered tamoxifen for inducible SynGAP1 re-expression at postnatal day 21.

Main Results:

• SynGAP1 haploinsufficiency selectively reduced SynGAP-containing complexes without broadly affecting NMDA-dependent responses.
• Post-developmental SynGAP1 re-expression fully restored SynGAP module interactions in the hippocampus.
• Re-expression also normalized secondary alterations in Shank-Homer complexes in the somatosensory cortex.

Conclusions:

• Biochemical restoration of disrupted synaptic networks is achievable post-development.
• Genetic reactivation of haploinsufficient synaptic regulators can normalize molecular networks.
• While critical periods may limit functional recovery, molecular normalization is possible.