Arias Natalia, Méndez Marta, Arias Jorge L
Laboratorio De Neurociencias, Departamento De Psicología, Universidad De Oviedo, Oviedo, Spain.
INEUROPA, Instituto De Neurociencias Del Principado De Asturias, Spain.
Hippocampus. 2015 Nov;25(11):1242-9. doi: 10.1002/hipo.22430. Epub 2015 Mar 26.
The importance context has been broadly studied in the management of phobias and in the drug addiction literature. The way in which changes to a context influence behavior after the simple acquisition of a passive avoidance task remains unclear. The hippocampus has long been implicated in the contextual and spatial processing required for contextual fear, but its role in encoding the aversive component of a contextual fear memory is still inconclusive. Our work tries to elucidate whether a change in context, represented as differences in the load of the stimuli, is critical for learning about the context-shock association and whether this manipulation of the context could be linked to any change in metabolic brain activity requirements. For this purpose, we used an avoidance conditioning task. Animals were divided into three different experimental conditions. In one group, acquisition was performed in an enriched stimuli environment and retention was performed in a typically lit chamber (the PA-ACQ-CONTX group). In another group, acquisition was performed in the typically lit chamber and retention was undertaken in the highly enriched chamber (the PA-RET-CONTX group). Finally, for the control group, PA-CN-CONTX, acquisition, and retention were performed in the enriched stimuli environment. Our results showed that the PA-ACQ-CONTX group had longer escape latencies and poorer retention than the PA-RET-CONTX and PA-CN-CONTX groups after 24 h of acquisition under contextual changes. To study metabolic brain activity, histochemical labelling of cytochrome c-oxidase (CO) was performed. CO results suggested a neural circuit including the hippocampus, amygdala, thalamus, parahippocampal cortices, and mammillary nuclei that is involved in the learning and memory processes that enable context-dependent behavior. These results highlight how dysfunction in this network may be involved in the contextualization of fear associations that underlie several forms of psychopathology, including post-traumatic stress disorder, schizophrenia, and substance abuse disorders.
情境的重要性已在恐惧症管理和药物成瘾文献中得到广泛研究。在简单习得被动回避任务后，情境变化影响行为的方式仍不清楚。长期以来，海马体一直被认为与情境恐惧所需的情境和空间处理有关，但其在编码情境恐惧记忆的厌恶成分中的作用仍无定论。我们的研究试图阐明，以刺激负荷差异表示的情境变化对于学习情境 - 电击关联是否至关重要，以及这种情境操纵是否可能与大脑代谢活动需求的任何变化相关联。为此，我们使用了回避条件任务。动物被分为三种不同的实验条件。在一组中，在丰富刺激环境中进行习得，在典型光照的房间中进行保持（PA - ACQ - CONTX组）。在另一组中，在典型光照的房间中进行习得，在高度丰富的房间中进行保持（PA - RET - CONTX组）。最后，对于对照组PA - CN - CONTX，在丰富刺激环境中进行习得和保持。我们的结果表明，在情境变化下习得24小时后，PA - ACQ - CONTX组的逃避潜伏期比PA - RET - CONTX组和PA - CN - CONTX组更长，保持能力更差。为了研究大脑代谢活动，进行了细胞色素c氧化酶（CO）的组织化学标记。CO结果表明，一个包括海马体、杏仁核、丘脑、海马旁皮质和乳头体核的神经回路参与了使情境依赖行为成为可能的学习和记忆过程。这些结果突出了该网络功能障碍可能如何参与恐惧关联的情境化，而恐惧关联是包括创伤后应激障碍、精神分裂症和物质使用障碍在内的几种精神病理学形式的基础。
