Lim Wei Ling, Soga Tomoko, Parhar Ishwar S
Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Selangor, Malaysia.
Dev Neurosci. 2014;36(2):95-107. doi: 10.1159/000360416. Epub 2014 Apr 3.
Migration and final positioning of gonadotropin-releasing hormone (GnRH) neurons in the preoptic area (POA) is critical for reproduction. It is known that maternal dexamethasone (DEX) exposure impairs reproductive function and behaviour in the offspring. However, it is still not known whether maternal DEX exposure affects the postnatal GnRH neurons in the offspring. This study determined the neuronal movement of enhanced green fluorescent protein (EGFP)-tagged GnRH neurons in slice culture of postnatal day 0 (P0), P5 and P50-60 transgenic male rats. Effect of maternal DEX treatment on EGFP-GnRH neuronal movement and F-actin distribution on GnRH neurons at P0 stage were studied. Time-lapse analysis of P0 and P5 EGFP-GnRH neurons displayed active cellular movement within the POA compared to young adult P50-60 stages, suggesting possible fine-tuning movement for positioning of early postnatal GnRH neurons. The DEX-treated EGFP-GnRH neurons demonstrated decreased motility in the POA and reduced F-actin distribution in the GnRH neurons at 60 h culture compared to the vehicle-treated. These results suggest that the P0 GnRH neuronal movement in the POA is altered by maternal DEX exposure, which possibly disrupts the fine-tuning process for positioning and development of early postnatal GnRH neurons in the brain, potentially linked to reproductive dysfunction in adulthood.
促性腺激素释放激素（GnRH）神经元在前脑视前区（POA）的迁移和最终定位对生殖至关重要。已知母体暴露于地塞米松（DEX）会损害后代的生殖功能和行为。然而，母体DEX暴露是否会影响后代出生后的GnRH神经元尚不清楚。本研究确定了出生后第0天（P0）、P5和P50 - 60天转基因雄性大鼠脑片培养中增强型绿色荧光蛋白（EGFP）标记的GnRH神经元的神经元运动。研究了母体DEX处理对P0期EGFP - GnRH神经元运动和GnRH神经元上F - 肌动蛋白分布的影响。与成年早期P50 - 60阶段相比，对P0和P5期EGFP - GnRH神经元的延时分析显示POA内细胞有活跃运动，提示出生后早期GnRH神经元定位可能存在精细调节运动。与载体处理组相比，DEX处理的EGFP - GnRH神经元在培养60小时时POA内运动性降低，GnRH神经元中F - 肌动蛋白分布减少。这些结果表明，母体DEX暴露会改变POA中P0期GnRH神经元的运动，这可能会破坏出生后早期GnRH神经元在脑内定位和发育的精细调节过程，这可能与成年期生殖功能障碍有关。
