State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Physiol Behav. 2011 Sep 1;104(3):429-36. doi: 10.1016/j.physbeh.2011.04.062. Epub 2011 May 5.
Mongolian gerbils (Meriones unguiculatus) display food hoarding and thus provide an opportunity to study the neuromechanisms underlying this behavior. In the present study, male gerbils exhibited a bimodal expression of food hoarding behavior-some displayed high levels of food hoarding whereas others virtually lacked this behavior under normal laboratory conditions with free access to food. Food hoarding was found to be associated with an increase in neuronal activation, indicated by Fos immunoreactive (ir) staining, in several brain areas including the nucleus accumbens, ventral tegmental area (VTA), and lateral hypothalamus. Food hoarding was also associated with increases in the number of cells labeled for tyrosine hydroxylase (TH-ir), the rate limiting enzyme for dopamine conversion, and the number of cells co-labeled for TH-ir/Fos-ir in the VTA, suggesting that dopamine in the brain reward circuitry may be involved in food hoarding. Further, we found that 22 h of food deprivation induced food hoarding in some, but not all, males that naturally did not display food hoarding. In these males, however, food hoarding did not increase TH-ir or TH-ir/Fos-ir expression in the VTA. Together, these data indicate that male Mongolian gerbils display diverse phenotypes of food hoarding behavior and that dopamine in the brain reward circuitry may be involved in the control of naturally occurring, but not food deprivation-induced, food hoarding.
蒙古沙鼠（Meriones unguiculatus）表现出食物囤积行为，因此为研究这种行为的神经机制提供了机会。在本研究中，雄性沙鼠表现出食物囤积行为的双峰表达——一些表现出高水平的食物囤积，而另一些在正常实验室条件下几乎没有这种行为，食物可以自由获取。研究发现，食物囤积与几个脑区神经元激活的增加有关，如伏隔核、腹侧被盖区（VTA）和外侧下丘脑，这些脑区用 Fos 免疫反应（ir）染色来表示。食物囤积还与 VTA 中酪氨酸羟化酶（TH-ir）标记细胞数量的增加、多巴胺转化的限速酶有关，以及 TH-ir/Fos-ir 共标记细胞数量的增加有关，这表明大脑奖励回路中的多巴胺可能参与了食物囤积。此外，我们发现 22 小时的食物剥夺会诱导一些但不是所有原本不表现出食物囤积的雄性沙鼠进行食物囤积。然而，在这些雄性沙鼠中，食物囤积并没有增加 VTA 中的 TH-ir 或 TH-ir/Fos-ir 表达。综上所述，这些数据表明雄性蒙古沙鼠表现出不同的食物囤积行为表型，而大脑奖励回路中的多巴胺可能参与了对自然发生的而非食物剥夺诱导的食物囤积的控制。
