The Overwhelmed Gate: Autism as Thalamic Reticular Nucleus Hyperexcitability

This paper proposes that autism is a gate filtering failure produced by TRN hyperexcitability — not a social brain disorder. When the thalamic reticular nucleus threshold drops too low, signals that should be suppressed enter conscious experience, flooding the self with inputs it cannot selectively filter. Sensory hypersensitivity, attentional flooding, repetitive stabilizing behaviors, and sleep disruption are not separate symptoms requiring separate explanations — they are the same threshold failure expressing across every domain TRN is responsible for. Causality is established in both directions in animal models. Two subtypes are identified: TRN excitability failure in Cntnap2 autism and tool-level connectivity failure in Shank3 autism, each requiring a different intervention. The heterogeneity of autism treatment response is mechanistically predictable from this distinction.