cAMP反应元件结合蛋白(CREB)在正常发育大鼠视皮层的表达研究

正常视觉信息输入对初期视皮层的发育和修饰至关重要。视觉发育的特点是存在一个关键期 ,在此期内控制信息输入将导致皮质联系的显著变化。转录因子 -c AMP反应元件结合蛋白 ( CREB)在多种有机体的信号传导通路中的枢纽作用和其参与长时程突触可塑性的生理活动提示 ,它可能参与了在视皮层发育中发挥重要作用的分子机制。本研究应用免疫组织化学方法和 Western blot技术 ,对 P14、P2 2、P3 0、P45和 P90年龄组 Sprague-Dawley大鼠视皮层内 CREB的免疫反应性进行观察和分析。结果证明 ,CREB在视皮层各层内的蛋白表达时程与视觉发育的关键期一致 ,其免疫反应性在 P2 2至 P45期间达到高水平 ,成年后的蛋白表达出现下调。结论 :视觉可塑性降低的同时存在 CREB表达的显著改变 ,但该蛋白表达改变与突触传递和可塑性的关系尚待阐明

INVESTIGATION OF CYCLIC AMP RESPONSE ELEMENT BINDING PROTEIN (CREB) EXPRESSION IN NORMAL DEVELOPMENTAL VISUAL CORTEX OF RATS

The normal visual input is vital for the development and modification of primary visual cortex and visual development is typified by a critical period when manipulating input will cause dramatic changes in cortical connectivity. The pivotal role of transcription factor cyclic AMP response element binding protein (CREB) in signal transduction pathways, together with its function in physiological activities of long-term synaptic plasticity in a variety of organisms, suggests that CREB might be involved in the mechanisms that play important roles in the visual cortex development. Therefore in the present study, we applied specific antibodies recognizing CREB to the primary visual cortex at P14, P22, P30, P45 and P90 and investigated CREB immunoreactivity in the Sprague-Dawley rat visual cortex at a range of developmental stages. The results from the immunohistochemistry and Western blot experiments demonstrated that the CREB protein expression changes with normal visual development and the CREB immunoreactivity peaked in layers Ⅱ-Ⅵ during the critical period. These results indicate that there is correlation between CREB protein expression and the time course of normal visual development. How these changes of immunoreactivity relate to synaptic transmission and plasticity needs to be further clarified.