Mullany P, Lynch M A
Department of Physiology, Trinity College, Dublin, Ireland.
Neuropharmacology. 1997 Jul;36(7):973-80. doi: 10.1016/s0028-3908(97)00073-7.
We have examined protein synthesis in entorhinal cortex following induction of long-term potentiation (LTP) in perforant path-granule cell synapses. The data presented here indicate that there was an increase in [35S]methionine labelling of TCA-precipitated proteins and [35S]methionine labelling of synaptophysin in the ipsilateral entorhinal cortex 40 min after induction of LTP in dentate gyrus. Intraventricular injection of both the NMDA antagonist, D-amino-phosphonovalerate, and the protein synthesis inhibitor, anisomycin reduced protein synthesis though the decrease caused by anisomycin was much more profound. Both agents blocked induction of LTP and the increase in protein synthesis and synaptophysin synthesis which accompanied LTP. These data indicate a close coupling of increased protein synthesis in the entorhinal cortex and expression of LTP in the dentate gyrus. This coupling was further suggested by the absence of an LTP-associated increase in protein synthesis in aged animals, in which LTP was markedly attenuated. The possibility that these changes impact on morphological changes which accompany LTP is discussed.
我们检测了在穿通通路-颗粒细胞突触诱导长时程增强（LTP）后内嗅皮质中的蛋白质合成。此处呈现的数据表明，在齿状回诱导LTP 40分钟后，同侧内嗅皮质中三氯乙酸沉淀蛋白的[35S]甲硫氨酸标记以及突触素的[35S]甲硫氨酸标记均增加。脑室内注射NMDA拮抗剂D-氨基磷酸戊酸和蛋白质合成抑制剂茴香霉素均可降低蛋白质合成，不过茴香霉素引起的降低更为显著。两种药物均阻断了LTP的诱导以及伴随LTP的蛋白质合成和突触素合成的增加。这些数据表明内嗅皮质中蛋白质合成增加与齿状回中LTP的表达紧密相关。老年动物中不存在与LTP相关的蛋白质合成增加，而其LTP明显减弱，这进一步提示了这种相关性。本文还讨论了这些变化影响伴随LTP的形态学变化的可能性。
