| Abstrakt: |
Bidirectional connections between the immune system and the nervous system are well established in mammals, and there is solid evidence for their existence in mollusks. However, the issue has been relatively neglected in insects. There is indirect evidence suggesting that immune systems and nervous systems interact in insects. For example, injection of bacterial products such as lipopolysaccharides results in reproducible changes in behavior similar to the changes observed in vertebrates in response to bacterial exposure. Insects exposed to bacterial products may exhibit behavioral fever, illness-induced anorexia, decreased learning ability and increased egg laying, suggesting that immune activity can alter neural function. As in vertebrates, the expression of certain behaviors, such as flight-or-fight, results in transient immunosuppression, suggesting that neural activity influences immune function. Indirect evidence hints at the identity of compounds mediating immune-neural connections. For example, neurohormonally released octopamine appears to alter immune function. Growth-blocking peptide produced by immune cells increases dopamine production within the central nervous system. In mammals, neural-immune bidirectional connections are critical for the proper functioning of the immune system. Our poor understanding of neural-immune interactions in insects may limit our ability to comprehend insect immune systems. [ABSTRACT FROM AUTHOR] |
