Lehner Małgorzata, Taracha Ewa, Skórzewska Anna, Turzyńska Danuta, Sobolewska Alicja, Maciejak Piotr, Szyndler Janusz, Hamed Adam, Bidziński Andrzej, Wisłowska-Stanek Aleksandra, Płaźnik Adam
Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
Behav Brain Res. 2008 Mar 17;188(1):154-67. doi: 10.1016/j.bbr.2007.10.033. Epub 2007 Nov 4.
The aim of the study was to examine the neurochemical background of differences in the individual responses to conditioned aversive stimuli, using the strength of a rat conditioned freezing response (the contextual fear test), as a discriminating variable. It was shown that low responders (LR), i.e. rats with duration of a freezing response one standard error, or more, below the mean value, had a higher activity of the M2 cortical area, and the median raphe nucleus (c-Fox expression), in comparison to the high responders (HR), i.e. rats with the duration of a freezing response one standard error, or more, above the mean value. These animals had also stronger 5-HT- and CRF-related immunostaining in the M2 area, and increased concentration of GABA in the basolateral nucleus of amygdala (in vivo microdialysis). The LR group vocalized more during test session in the aversive band, and had higher serum levels of corticosterone, examined 10 min after test session. It was shown that different natural patterns of responding to conditioned aversive stimuli are associated with different involvement of brain structures and with dissimilar neurochemical mechanisms.
本研究的目的是利用大鼠条件性僵住反应的强度（情境恐惧试验）作为区分变量，来研究个体对条件性厌恶刺激反应差异的神经化学背景。结果表明，低反应者（LR），即僵住反应持续时间比平均值低一个标准误差或更多的大鼠，与高反应者（HR），即僵住反应持续时间比平均值高一个标准误差或更多的大鼠相比，其M2皮质区域和中缝大核（c-Fox表达）的活性更高。这些动物在M2区域的5-HT和CRF相关免疫染色也更强，杏仁核基底外侧核中的GABA浓度增加（体内微透析）。LR组在厌恶频段的测试过程中叫得更多，且在测试结束10分钟后检测到其血清皮质酮水平更高。结果表明，对条件性厌恶刺激的不同自然反应模式与脑结构的不同参与程度以及不同的神经化学机制有关。
