Regional Expression Profiles of Artemin Protein and GFRα3 mRNA During Postnatal Brain Development in Rats

Artemin, a member of the glial cell line-derived neurotrophic factor family, plays important roles in neuronal processes through GDNF family receptor alpha 3 (GFRα3)-mediated signaling. However, the expression patterns of Artemin and GFRα3 during normal postnatal brain development remain poorly characterized. This study characterized regional Artemin protein and Gfra3 messenger RNA (mRNA) expression profiles in the rat brain at distinct stages of postnatal development. Male Wistar rats aged 9, 41, and 70 days (n = 10/group) were examined. Artemin levels were quantified in the prefrontal cortex, striatum, and cerebellum using enzyme-linked immunosorbent assay (ELISA), whereas Gfra3 mRNA expression was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Regional and age-related differences were evaluated statistically. No significant age-related differences in Artemin levels were observed within any brain region. However, cerebellar Artemin levels were significantly higher than those in the prefrontal cortex and striatum across all age groups. Age-related changes in Gfra3 mRNA expression were detected only in the cerebellum, where expression was significantly higher in 41-day-old rats than in both 9- and 70-day-old rats and was also significantly higher in 70-day-old rats than in 9-day-old rats. Regional differences in Gfra3 mRNA expression were detected only in 41-day-old rats, with significantly higher expression in the cerebellum than in the prefrontal cortex and striatum. These findings provide, to our knowledge, the first comprehensive characterization of Artemin protein and Gfra3 mRNA expression at distinct stages of normal postnatal brain development and highlight the cerebellum as a region characterized by consistently higher Artemin levels and developmentally variable Gfra3 mRNA expression, supporting further investigation of Artemin–GFRα3 signaling in this region during postnatal brain development.