IL1B and Anxiety: That this might be possible is supported by data showing that intraperitoneal injection of single or combination proinflammatory cytokines (IL-1β, IL-6 and TNF-α) influence neuroendocrine activity, which promotes sickness behavior, anxiety, and anhedonia accompanied by neurotransmitter alterations in different brain areas such as the amygdala, hippocampus, locus coeruleus, and medial prefrontal cortex; sickness behavior persisted for 24 h after cytokine administration [12].