Autonomic-salience stability as a candidate Gate for awake low-dose ketamine: a systems neuroscience framework with a clinical anchor

Summary

Ketamine responses in patients vary, indicating that dose alone is insufficient to explain effects. A proposed framework suggests that low-dose ketamine enhances network flexibility while autonomic-salience stability may determine how this flexibility is utilized. Observations from a nonrandomized clinical setting support the framework but do not provide evidence for efficacy or biomarker validity. Future studies should explore how autonomic shifts impact treatment outcomes and test the framework's predictions.

Study at a glance

Abstract

Ketamine responses vary across patients and sessions, suggesting that dose alone is an incomplete organizing principle. We propose a state-first Gate-Amplifier-Reintegration framework in which awake low-dose ketamine acts primarily as an Amplifier of transient network flexibility, whereas autonomic-salience stability is treated as a candidate Gate that may shape whether this flexibility remains steerable. In this framework, cardio-autonomic and interoceptive state may constrain or modulate salience-network gain, interoceptive precision, and thalamocortical selectivity, thereby influencing whether ketamine-associated loosening of default-mode constraints is available for frontoparietal-control-compatible reintegration or drifts toward dysphoric dissociation and vigilance instability. We formalize a three-step sequence: Gate, Amplifier, Reintegration. Gate refers to candidate autonomic-salience stability; Amplifier refers to awake low-dose ketamine delivered under operational invariants that preserve vigilance and behavioral interpretability; Reintegration refers to the organization of ketamine-amplified flexibility into language, joint attention, task context, and action-oriented consolidation. Heart-rate variability (HRV) is used only as a bounded peripheral state-verification proxy. We distinguish observed Autonomic Affirmative Window quality assurance (AAW-QA), a post-sequence quality-assurance signal, from AAW-Gate, a proposed prospective pre-dose criterion. The framework is informed by, but not validated by, observations from a single-center outpatient chronic pain care pathway using awake low-dose ketamine and route-defined cervicothoracic sympathetic modulation. These observations document clinical provenance but do not provide comparative efficacy evidence, causal efficacy, dose-sparing evidence, salience-network mediation, or HRV biomarker validity. The clinical provenance was nonrandomized, chart-based, clinician-directed, and lacked concurrent neural measurement. The framework yields falsifiable predictions: prospective Gate manipulation should reproducibly alter pre-dose autonomic state; prospectively defined AAW-Gate-positive sessions should be tested for convergence with low-burden EEG/fNIRS markers of salience switching and task control; and randomized Gate designs should determine whether autonomic shifts moderate, and in adequately powered designs mediate, session-level tolerability, reintegration, and usable clinical change. Alternative accounts, including analgesia, expectancy, clinician attention, workflow era, documentation bias, respiratory/postural effects, and photoplethysmography (PPG) artifact, are treated as competing explanations that future designs must separate.

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