A clinical hallmark of hypertension is impairment of the cardiac vagal baroreflex, which maintains stable blood pressure and heart rate under physiological conditions. There is also evidence that oxidative stress in the brain is associated with neurogenic hypertension. However, whether an oxidative stress-induced disruption of the functional connectivity between nucleus tractus solitarii (NTS), the terminal site of baroreceptor afferents, and nucleus ambiguus (NA), the origin of the vagus nerve, underpins the impaired cardiac vagal baroreflex during neurogenic hypertension has not been assessed. the present study tested the hypothesis that an augmented superoxide level in the NTS contributes to the depression of cardiac vagal baroreflex during neurogenic hypertension by disrupting the functional connectivity between the NTS and NA. An experimental model of neurogenic hypertension that employed intracerebroventricular infusion of angiotensin II by osmotic minipump in male adult C57BL/6 mice was used. Based on tractographic evaluations using magnetic resonance imaging/diffusion tensor imaging of the brain stem, we found that the functional connectivity between the NTS and NA was disrupted during neurogenic hypertension, concurrent with depression of the cardiac vagal baroreflex detected by radiotelemetry. We further found that the disrupted NTS-NA functional connectivity was reversible, and was related to oxidative stress induced by augmented levels of NADPH oxidase-generated superoxide in the NTS. We conclude that depression of the cardiac vagal baroreflex induced by oxidative stress in the NTS during neurogenic hypertension may be manifested in the form of dynamic alterations in the functional connectivity between the NTS and NA.