TNF and autoimmune hepatitis: The major findings of this study include: (1) TNFR1 expression is increased on phrenic motor neurons in 28d CTB-SAP rats vs. controls and 7d CTB-SAP rats; (2) astrocytic number is significantly increased in CTB-SAP rats vs. controls, and astrocytes display a reactive (activated) morphology in CTB-SAP rats vs. controls; and (3) TNF-α signaling contributes to the enhanced AIH-induced pLTF observed in 7d CTB-SAP rats, while TNF-α signaling constrains AIH-induced pLTF in 28d CTB-SAP rats.