NKCC1 INHIBITION PREVENTS DYSREGULATION OF STRESS AND INFLAMMATORY SIGNALING, INTERGENERATIONAL BRAIN-GUT-MICROBIOTA AXIS DISRUPTION AND BEHAVIORAL ABNORMALITIES FOLLOWING MATERNAL PRECONCEPTION TBI

We investigated the roles of the hypothalamic‑pituitary‑adrenal (HPA) axis and inflammatory signaling in the initiation of intergenerational abnormalities following maternal preconception traumatic brain injury (TBI), how pre‑ and postnatal maternal factors influence offspring development, and a pharmacological approach for prevention. Female rats (F0) received a moderate TBI via midline fluid percussion injury on postnatal day 60 (P60) (F0F_T group). A subset of F0F_T received bumetanide, an NKCC1 inhibitor, prior to injury. At P90, F0 females were bred. From birth to weaning (P21), half of the offspring were reared by their biological dams, and the other half were cross‑fostered to dams from the opposite treatment group. F0F_T females exhibited elevated stress and inflammatory markers and mild microbiome alterations, while weight, behavior, and maternal care remained unchanged. Their male offspring showed reduced birth and weaning weights, elevated inflammatory markers, dysregulated HPA axis stress responses, gut dysbiosis, reduced sociability, increased anxiety, and impaired spatial memory. Female offspring showed similar weight and anxiety changes but were otherwise unaffected. Cross‑fostered offspring displayed phenotypes shifted toward those of the foster dams’ biological offspring reared by biological dams. Bumetanide prevented stress, inflammatory, and microbiome alterations in F0F_T females and mitigated most abnormalities in their offspring. TBI induces stress and inflammatory dysregulation in dams and sex‑dependent microbiome and neurobehavioral abnormalities in offspring through maternal prenatal and postnatal influences. Bumetanide’s mitigating effects implicate maternal stress and inflammation as drivers of the observed abnormalities in both generations and NKCC1 as a potential therapeutic target.