Abstract: Objective   To explore the expression changes of Hippo signaling pathway core protein at different time points of postnatal mice cortex.   Methods    Brain weight and transverse diameter were measured at 3 d, 6 d, 9 d, 3w and 8w postnatal (P) mice cortex of C57BL/6 to detect the growth and development of mice brain tissue.  Western Blot was used to detect the expression of MST1 and LATS1. Tyramide Signal Amplification (TSA) was used to detect the changes of microglia numbers and the location of Yes-associated protein (YAP) in microglia at five different time points.   Results   The brain weight and transverse diameter in the early postnatal period was significantly increased. Western blot result showed that MST1 and LATS1 were  significantly decreased from P9d, and there was no statistical difference in P3w and P8w. The proportion of IBA1 positive microglia in cortex were increased with the increasing of age, with a significant increase in the early postnatal period. With the increasing number of microglia, YAP aggregation transferred from extranuclear to intranuclear.   Conclusions   Hippo signaling pathway is activated in early postnatal mice cortex, which may be involved in volume regulation during postnatal brain development.

Key words: Hippo signaling pathway; ,  ,  Microglia; ,  , C57BL/6 mice