Winograd Milena, Viola Haydée
Instituto de Biología Celular y Neurociencias, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Hippocampus. 2004;14(1):117-23. doi: 10.1002/hipo.10153.
There is a growing body of evidence showing that the formation of associative memories is associated with an increase in phosphorylated cAMP response element-binding protein (pCREB) levels. We recently reported increased pCREB levels in the rat hippocampus after an exploration to a novel environment. In the present work, we studied whether this increment in CREB activation is associated with the formation of memory of habituation to a novel environment or with the detection of novelty. Rats were submitted to consecutive open field sessions at 3-h intervals. Measurement of the hippocampal pCREB level, carried out 1 h after each training session, showed that (1) it did not increase when rats explored a familiar environment; (2) it did not increase after a reexposure that improves the memory of habituation; (3) it increased after a brief novel exploration unable to form memory of habituation; and (4) it increased in amnesic rats for spatial habituation. Taken as a whole, our results suggest that the elevated pCREB level after a single open field exploration is not associated with the memory formation of habituation. It is indeed associated with the detection of a novel environment.
越来越多的证据表明，联想记忆的形成与磷酸化环磷酸腺苷反应元件结合蛋白（pCREB）水平的增加有关。我们最近报道，大鼠在探索新环境后海马体中的pCREB水平会升高。在本研究中，我们探讨了CREB激活的这种增加是与对新环境的习惯化记忆的形成有关，还是与对新奇事物的察觉有关。大鼠每隔3小时接受一次连续的旷场实验。在每次训练后1小时测量海马体pCREB水平，结果显示：（1）当大鼠探索熟悉环境时，pCREB水平没有增加；（2）在重新暴露后（这种重新暴露可改善习惯化记忆），pCREB水平没有增加；（3）在一次短暂的新环境探索（无法形成习惯化记忆）后，pCREB水平增加；（4）在空间习惯化失忆的大鼠中，pCREB水平增加。总体而言，我们的结果表明，单次旷场实验后pCREB水平升高与习惯化记忆的形成无关，而确实与对新环境的察觉有关。
