March Amelia, Borchelt David, Golde Todd, Janus Christopher
Comp Med. 2014 Feb;64(1):4-12.
Fear-conditioning testing paradigms have been used to study differences in memory formation between inbred mouse strains, including numerous mouse models of human diseases. In this study, we characterized the conditioned fear memory of 3 inbred strains: C57BL/6NCrl, 129S2/SvPasCrl, and FVB/NCrl, obtained from Charles River Laboratories. We used 2 training paradigms: delay conditioning, in which an unconditional stimulus coterminates with the presentation of a conditional stimulus, and trace conditioning, in which the conditional and unconditional stimuli are separated by a trace interval. In each paradigm, we evaluated the recent (3 d) and remote (25 d) memory of the mice by using a longitudinal design. Our results showed that both C57BL/6NCrl and 129S2/SvPasCrl mice developed strong and long-lasting context and tone memories in both paradigms, but FVB/NCrl mice showed a weaker but nevertheless consistent tone memory after delay training. Tone memory in the FVB strain was stronger in male than female mice. The remote tone memory of 129S2/SvPasCrl mice diminished after delay training but was stable and stronger than that of C57BL/6NCrl mice after trace training. In conclusion, both C57BL/6NCrl and 129S2/SvPasCrl mice showed reliable and long-lasting fear memory after delay or trace training, with 129 mice showing particularly strong tone memory after trace conditioning. The FVB/NCrl strain, especially male mice, showed reliable tone fear memory after delay training. Our findings confirm that both C57BL/6NCrl and 129S2/SvPasCrl mice develop strong context and tone memory in delay and trace fear-conditioning paradigms.
恐惧条件测试范式已被用于研究近交系小鼠品系之间记忆形成的差异，包括众多人类疾病的小鼠模型。在本研究中，我们对从查尔斯河实验室获得的3个近交系品系：C57BL/6NCrl、129S2/SvPasCrl和FVB/NCrl的条件恐惧记忆进行了表征。我们使用了2种训练范式：延迟条件训练，即无条件刺激与条件刺激同时呈现；痕迹条件训练，即条件刺激和无条件刺激由一个痕迹间隔分开。在每种范式中，我们通过纵向设计评估了小鼠的近期（3天）和远期（25天）记忆。我们的结果表明，C57BL/6NCrl和129S2/SvPasCrl小鼠在两种范式中都形成了强烈且持久的情境和音调记忆，但FVB/NCrl小鼠在延迟训练后表现出较弱但仍一致的音调记忆。FVB品系中雄性小鼠的音调记忆比雌性小鼠更强。129S2/SvPasCrl小鼠的远期音调记忆在延迟训练后减弱，但在痕迹训练后稳定且比C57BL/6NCrl小鼠更强。总之，C57BL/6NCrl和129S2/SvPasCrl小鼠在延迟或痕迹训练后都表现出可靠且持久的恐惧记忆，129小鼠在痕迹条件训练后表现出特别强的音调记忆。FVB/NCrl品系，尤其是雄性小鼠，在延迟训练后表现出可靠的音调恐惧记忆。我们的研究结果证实，C57BL/6NCrl和129S2/SvPasCrl小鼠在延迟和痕迹恐惧条件测试范式中都形成了强烈的情境和音调记忆。
