The Neonatal Calibration Thesis proposes that the Periaqueductal Gray (PAG)—the brainstem structure governing innate defense cascades—exists at birth in a state of maximum configurational plasticity, characterized by excitatory GABAergic signaling, GluN2B-dominant NMDA receptor overexpression, and abundant silent synapses. This paper synthesizes evidence from developmental neuroscience, lactation biology, epigenetics, and attachment theory to demonstrate that human breast milk delivers a coordinated array of calibration signals—endocannabinoids (2-arachidonoylglycerol), glucocorticoids, microRNAs, and oxytocin—that configure PAG columnar sensitivity during a critical neonatal window (0–6 months). Drawing on the Lactocrine Hypothesis (Bartol et al.), Hinde’s milk cortisol–temperament research, Fride’s CB1-dependent suckling paradigm, and Weaver’s NR3C1 epigenetic programming model, we propose that the lactating dyad functions as a closed-loop biological control system. Formula feeding is framed as lactocrine signal deprivation—the absence of specific calibration inputs during heightened neural plasticity—rather than nutritional insufficiency. Cesarean delivery is identified as a risk factor for suboptimal initial PAG calibration. This framework provides the developmental origin story for Systemic Acquired Disorganized Attachment (SADA, Paper 1), explaining how neonatal calibration creates the latent vulnerability that manifests as attachment fragility under adult allostatic load.
Flemming Bust (Sat,) studied this question.