TNF and serum lipopolysaccharide activity: Further animal studies found that splenectomy and transection of the splenic nerve abolished the effects of vagus nerve stimulation (VNS) on systemic TNF-α released in response to endotoxemia and polymicrobial sepsis8, 9, 10 In other words, the vagus nerve modulated the TNF-α response of nAChR-positive splenic macrophages through signals transmitted via the splenic nerve.