Agüero A, Gallo M, Arnedo M, Molina F, Puerto A
Departamento de Psicología Experimental y Fisiología del Comportamiento, Universidad de Granada, Spain.
Neurobiol Learn Mem. 1997 Mar;67(2):161-6. doi: 10.1006/nlme.1996.3749.
The functional meaning of the visceral information processing in the medial parabrachial nucleus (PBNm) was analyzed in this study through a short-term aversion learning task. In this short-term task the animals (Wistar rats) had to learn to discriminate between two different gustatory-olfactory stimuli presented simultaneously (two graduated burettes); one of the stimuli was associated with the concurrent intragastric administration of an aversive chemical agent (hypertonic NaCl) and the other stimulus was paired with no injection. In the first experiment, the PBNm-lesioned animals are unable to learn the task using gustatory stimuli (saccharin and quinine) that surpassed the detection threshold of parabrachial-lesioned rats. Moreover, in a second experiment, the PBNm-lesioned animals were unable to learn the task when there was no initial preference for either of the gustatory-olfactory stimuli presented (strawberry or coconut). However, this short-term task is learned by lateral parabrachial nucleus (PBNl) lesioned animals. The possibility that the PBNm and the PBNl are involved in distinct mechanisms of visceral processing is discussed.
本研究通过一项短期厌恶学习任务，分析了臂旁内侧核（PBNm）内内脏信息处理的功能意义。在这项短期任务中，动物（Wistar大鼠）必须学会区分同时呈现的两种不同味觉-嗅觉刺激（两个刻度滴定管）；其中一种刺激与同时胃内注射厌恶化学剂（高渗NaCl）相关联，另一种刺激则不进行注射配对。在第一个实验中，PBNm损伤的动物无法使用超过臂旁损伤大鼠检测阈值的味觉刺激（糖精和奎宁）来学习任务。此外，在第二个实验中，当对所呈现的任何一种味觉-嗅觉刺激（草莓或椰子）都没有初始偏好时，PBNm损伤的动物无法学习该任务。然而，臂旁外侧核（PBNl）损伤的动物能够学会这项短期任务。文中讨论了PBNm和PBNl参与不同内脏处理机制的可能性。
