Serotonin-interleukin pathway in neurological disorders: A mixed pathway approach

Neurological disorders involve complex interactions between neurotransmitters and immune signaling pathways, with serotonin (5-HT) and interleukins (ILs) playing crucial roles. This review explores the mixed pathway of 5-HT-IL signaling and its involvement in the pathophysiology of neurodegenerative and neuropsychiatric conditions. Dysregulated 5-HT and IL signaling has been implicated in Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, depression, anxiety, schizophrenia, autism spectrum disorder, and attention-deficit/hyperactivity disorder. 5-HT influences neuroinflammation, synaptic plasticity, and cognitive function, while ILs regulate immune responses and neuronal survival. Their interplay modulates neurotransmission, neuroinflammation, and neurodegeneration through mechanisms, such as cytokine-mediated 5-HT depletion and 5-HT receptor regulation. Understanding the 5-HT-IL pathway offers new insights into disease progression and potential therapeutic strategies, including selective 5-HT reuptake inhibitors, cytokine inhibitors, and combination therapies targeting neuroimmune interactions.