Inhibition of nitric oxide synthase accentuates endotoxin-induced sickness behavior in mice

► Sickness behavior is a motivational state triggered by activation of immune system. ► Both a detrimental and beneficial role of NO was observed during immune challenges. ► The inhibition of iNOS accentuate LPS-induced the behavioral changes. ► NO may have a protective role to limit LPS-induced sickness behavior.