FUNCTIONAL RECOVERY THRESHOLD (FRT) A conceptual and experimental framework for studying the recoverability of neuronal function following an acute energy crisis.

Abstract

Abstract This conceptual research proposal introduces the Functional Recovery Threshold (FRT) as an operational framework for studying the boundary between observable neuronal dysfunction and subsequent functional recoverability following acute energetic stress. The central question is whether neuronal function can become experimentally unobservable while the capacity for subsequent recovery remains preserved, and whether biological mechanisms can influence this transition. The proposed experimental model uses oxygen-glucose deprivation followed by reperfusion (OGD/R) and longitudinal microelectrode array (MEA) recordings to quantify neuronal network activity and construct a functional recovery curve across increasing durations of energetic stress. FRT50 is defined as the OGD duration corresponding to a modeled 50% probability of meeting a prespecified functional-recovery criterion under defined experimental conditions. Importantly, FRT50 is treated as a model-derived parameter rather than as a presumed biological point of no return. The framework proposes sequential testing of candidate mechanisms, beginning with the NLRP3-caspase-1-GSDMD pathway and extending, where justified, to sigma-1 receptor (σ1R)-associated ER-mitochondrial signaling and N,N-dimethyltryptamine (DMT) as a candidate endogenous mediator. Functional recovery, cellular viability, and subsequent cellular injury are treated as distinct experimental outcomes. Existing evidence supports individual components of this framework in specific experimental models, but no cited study establishes the complete proposed causal pathway or demonstrates an endogenous DMT-dependent shift in FRT. The project therefore defines this relationship as an experimentally testable hypothesis rather than an established mechanism. The proposed framework may provide a quantitative approach for distinguishing functional recoverability from subsequent cellular injury and for identifying biological mechanisms that influence recovery following acute energetic stress.