RNA Binding Motif Protein 8a (RBM8A), a component of the exon junction complex, plays a crucial role in neurodevelopmental disorders by regulating gene expression at various levels. While expressed in neurons and astrocytes, RBM8A's specific role in GFAP-positive astrocytes remains unclear. To investigate, we created a conditional heterozygous knockout (KO) mouse line targeting Rbm8a in astrocytes. Reduced RBM8A expression correlated with increased mobility and altered anxiety, revealing the potential role of Rbm8a in neurodevelopmental disorders.