give review literature of sickness behav... - tlooto, The Most Powerful AcademicGPT

Sickness behavior is a complex, evolutionarily conserved set of behavioral and physiological changes that occur in response to infection or immune system activation. It manifests through symptoms such as lethargy, anorexia, decreased social interaction, fatigue, and cognitive impairment, representing a strategic reorganization of priorities in the organism to optimize recovery and conserve energy for immune defense [1][2]. At the molecular level, sickness behavior is primarily driven by the action of pro-inflammatory cytokines, notably interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFα). These cytokines are produced peripherally by immune cells in response to pathogens and communicate with the central nervous system (CNS) through distinct mechanisms. Rapid signaling occurs via primary afferent nerves, such as the vagus nerve, innervating the inflammatory site, while slower pathways involve cytokines diffusing into brain regions like the choroid plexus and