Mendoza Jorge, Angeles-Castellanos Manuel, Escobar Carolina
Departamento de Anatomía, Facultad de Medicina, Edificio B 4 Piso, Universidad Nacional Autónoma de México, México DF 04510, México.
Behav Brain Res. 2005 Mar 7;158(1):133-42. doi: 10.1016/j.bbr.2004.08.016.
Restricted feeding schedules (RFS) entrain behavioral and physiological rhythms even in suprachiasmatic nucleus ablated animals, suggesting the existence of a food-entrained oscillator. The nucleus accumbens is an important structure for the expression of motivational behaviors and because its anatomical subterritories, Shell (Acc-Sh) and Core (Acc-Co) establish connections with different functional systems, they may participate in a differential way in food-entrainment. A first experiment, explored the role of Acc-Sh and Acc-Co in food-entrainment using the immunohistochemical detection of the protein c-Fos as a transcriptional activation marker. Experiment 2 tested the differential effect of Acc-Sh and Acc-Co, NMDA excitotoxic lesions. Lesioned rats were entrained to RFS and locomotor activity and free fatty acids (FFA) concentrations were evaluated. Results data show that in the Acc-Sh there is an increase of c-Fos immunoreactivity in food-entrained rats principally during feeding, whereas c-Fos expression in the Acc-Co region was increased during feeding and also anticipating mealtime. FFA were entrained in both lesioned groups, but the basal level was lower in Core-lesion rats. All rats exhibited food anticipatory activity (FAA). However, FAA was increased in Shell-lesioned animals and was almost abolished in the Core-lesion rats. These data indicate that the accumbens nucleus is involved with behavioral and metabolic food-entrainment, and that there is a differential role between both subregions.
即使在视交叉上核被切除的动物中，限制进食时间表（RFS）也能诱导行为和生理节律，这表明存在食物诱导振荡器。伏隔核是表达动机行为的重要结构，并且由于其解剖亚区域，壳区（Acc-Sh）和核心区（Acc-Co）与不同的功能系统建立连接，它们可能以不同的方式参与食物诱导。第一个实验，使用蛋白质c-Fos的免疫组织化学检测作为转录激活标记，探讨了Acc-Sh和Acc-Co在食物诱导中的作用。实验2测试了Acc-Sh和Acc-Co、NMDA兴奋性毒性损伤的差异效应。对损伤大鼠进行RFS诱导，并评估其运动活动和游离脂肪酸（FFA）浓度。结果数据显示，在Acc-Sh中，食物诱导大鼠的c-Fos免疫反应性主要在进食期间增加，而Acc-Co区域的c-Fos表达在进食期间以及预期用餐时间时增加。两个损伤组的FFA都被诱导，但核心区损伤大鼠的基础水平较低。所有大鼠都表现出食物预期活动（FAA）。然而，壳区损伤动物的FAA增加，而核心区损伤大鼠的FAA几乎消失。这些数据表明伏隔核参与行为和代谢性食物诱导，并且两个亚区域之间存在差异作用。
