Acute cold exposure and rewarming enhanced spatial memory and activated the MAPK cascades in the rat brain

作者:Zheng Gang; Chen Yaoming; Zhang Xueping; Cai Tonjian; Liu Minychao; Zhao Fang; Luo Wenjing*; Chen Jingyuan
来源:Brain Research, 2008, 1239: 171-180.
DOI:10.1016/j.brainres.2008.08.057

摘要

Cold is a common stressor that is likely to occur in everyday occupational or leisure time activities. Although there is substantial literature on the effects of stress on memory from behavioral and pharmacologic perspectives, the effects of cold stress on learning and memory were little addressed. The aims of the present work were to investigate the effects of acute cold exposure on Y-maze learning and the activation of cerebral MAPK cascades of rats. We found that the 2-hour cold exposure (-15 degrees C) and a subsequent 30-min rewarming significantly increased the performance of the rats in the Y-maze test. Serum corticosterone (CORT) level was increased after the cold exposure. After a transient reduction following the cold exposure, the P-ERK levels in the hippocampus and PFC drastically increased 30 min later. The levels of P-JNK increased gradually after the cold exposure in all the three brain regions we investigated, but the level of P-p38 only increased in the PFC. The levels of GABA(A) receptor alpha 1 subunit remained unchanged after the cold exposure. Furthermore, the performance of rats treated with cold plus muscimol or bicuculline in the Y-maze test was similar to that of the rats treated with those CABAergic agents alone. These results demonstrated that acute cold exposure and the subsequent rewarming could result in enhanced performance of spatial learning and memory, and the activation of MAPKs in the brain. However, GABAA receptor may not be involved in the acute cold exposure-induced enhancement of memory.