Perspective: chicken models for studying the ontogenetic origin of neuropsychiatric disorders

Authors: HUANG, XIAOHONG - Purdue University; Cheng, Heng-Wei

Submitted to: Biomedicines
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2022
Publication Date: 5/17/2022
Citation: Huang, X., Cheng, H. 2022. Perspective: chicken models for studying the ontogenetic origin of neuropsychiatric disorders. Biomedicines. https://doi.org/10.3390/biomedicines10051155.
DOI: https://doi.org/10.3390/biomedicines10051155

Interpretive Summary: Chickens show aggression towards conspecifics in order to establish social dominance rank within a flock. As a socially transmitted learning behavior, aggression can become bullying when a chicken or multiple chickens peck repetitively to others. Injurious behavior prevention is a critical issue in the poultry industry due to increasing social stress, consequently enhancing gut microbiota dysbiosis and brain inflammation via the gut-brain axis. The current findings indicate that administration of tryptophan reduces aggressiveness in chickens before and during adolescence. These results may provide insights for animal scientists to develop management strategies to reduce injurious behaviors in poultry as well as other farm animals.

Technical Abstract: Nutrients and xenobiotics cross the blood-placenta barrier and potentially deposit in the fetal brain. The prenatal exposure affects the neuroendocrine and microbial development. The mechanism underlying the maternal risk factors reprograming the microbiota-gut-brain axis with long-lasting effects on psychosocial behaviors in offspring is not well known. In humans, it is not possible to assess the nutrient or xenobiotic deposition in the fetal brain and gastrointestinal system due to the ethical reasons. Moreover, the maternal-fetal microbe transfer during the gestation, natural labor, and breast-feeding constitutes the initial gut microbiome in the progeny, which is inevitable in the most widely utilized rodent models. The social predisposition in the precocial birds, including chickens, provides the possibility to test behavioral responses shortly after being hatched. Hence, chickens are advantageous in investigating the ontogenetic origin of behaviors. Chicken embryos are suitable for deposition assessment and mechanistic study due to the accessibility, self-contained development, uniform genetic background, robust microbiota, and easy in vivo experimental manipulation compared to humans and rodents. Hence, a chicken embryonic model is an alternative to the rodent models in assessing the fetal exposure effect on neurogenesis and investigating the mechanism of the ontogenetic origin of neuropsychiatric disorders.