Fink J S, Smith G P
J Comp Physiol Psychol. 1979 Feb;93(1):34-65. doi: 10.1037/h0077587.
Exploratory behaviors were examined after bilateral microinjections of 6-hydroxydopamine into two hypothalamic sites that produced different patterns of denervation of forebrain catecholamine terminal fields. After anterolateral injections rats locomoted and reared less in a novel open field, responded abnormally to changes in the degree of novelty of the open field, and investigated a novel object less. These are deficits in exploratory behavior because they were not secondary to the inhibition of open-field behavior by hyperemotionality, by general motor disability, or by the failure to detect novel spaces or objects. Such anterolateral injections produced loss of catecholamine fibers, determined histochemically, in neocortical, hippocampal, anterolateral hypothalamic, mesolimbic, mesocortical, and anteromedioventral striatal terminal fields and loss of dopaminergic perikarya in the A10 and anteromedial A9 cell groups. No deficits in exploratory behaviors occurred, however, after bilateral anteromedial 6-hydroxydopamine injections that denervated neocortical, hippocampal, and anteromedial hypothalamic catecholamine terminal fields. A critical forebrain catecholaminergic innervation for exploratory responses to novel stimuli may be within areas that were denervated by anterolateral but not by anteromedial hypothalamic 6-nydroxydopamine injections. These areas are mesolimbic, mesocortical, anteromedioventral, and anterolateral hypothalamic terminal fields.
在双侧向两个下丘脑部位微量注射6-羟基多巴胺后，研究了探索行为。这两个部位导致前脑儿茶酚胺终末场出现不同模式的去神经支配。在前外侧注射后，大鼠在新的旷场中活动和直立次数减少，对旷场新奇程度的变化反应异常，对新物体的探究减少。这些是探索行为的缺陷，因为它们并非继发于过度情绪化、一般运动障碍或未能检测到新空间或物体对旷场行为的抑制。组织化学测定显示，这种前外侧注射导致新皮质、海马、下丘脑前外侧、中脑边缘、中脑皮质和前内侧腹侧纹状体终末场的儿茶酚胺纤维丧失，以及A10和前内侧A9细胞群中的多巴胺能神经元胞体丧失。然而，在双侧注射前内侧6-羟基多巴胺使新皮质、海马和下丘脑前内侧儿茶酚胺终末场去神经后，未出现探索行为缺陷。对新刺激的探索反应的关键前脑儿茶酚胺能神经支配可能存在于前外侧而非前内侧下丘脑6-羟基多巴胺注射所致去神经的区域内。这些区域是中脑边缘、中脑皮质、前内侧腹侧和下丘脑前外侧终末场。
