Francis J, Hernández L L, Powell D A
Brain Res Bull. 1981 Feb;6(2):155-63. doi: 10.1016/s0361-9230(81)80041-x.
Rabbits received either bilateral lesions of the far lateral hypothalamus (LH), or sham-operate lesions. After recovery from surgery the animals were exposed to Pavlovian conditioning in which eyeblink (EB), electromyographic (EMG), and heart rate (HR) conditioned responses (CRs) were recorded. Adaptation, acquisition and extinction training were studied. Subsequent to conditioning, free-field activity, paraorbital electric shock thresholds, and HR unconditioned responses (URs) were measured. At the end of behavioral testing forebrain norepinephrine (NE), dopamine (DA), an serotonin (5-HT) concentrations were assessed. Animals with LH lesions did not differ from controls on EB responding during either adaptation or acquisition. However, lesioned animals revealed more EB CRs during extinction than control animals. EMG CRs were minimal in both groups of animals. Lesioned animals showed smaller HR changes than control animals during all phases of training, although HR CRs tended to consist of bradycardia in all animals. No differences were observed in either shock thresholds or open field activity as a result of LH lesions. Cortical and hippocampal 5-HT and NE concentrations were significantly depleted in lesioned as compared to control animals. These findings were interpreted within the framework of the phasic control of attention by midbrain modulation of forebrain structures; however, the interruption of downward going fibers which mediate brain stem cardiac control cannot be ruled out.
兔子接受了双侧下丘脑外侧区（LH）损伤或假手术损伤。手术后恢复后，让动物接受巴甫洛夫条件反射训练，记录眨眼（EB）、肌电图（EMG）和心率（HR）条件反应（CRs）。研究了适应、习得和消退训练。条件反射训练后，测量自由场活动、眶周电击阈值和HR非条件反应（URs）。在行为测试结束时，评估前脑去甲肾上腺素（NE）、多巴胺（DA）和血清素（5-HT）的浓度。LH损伤的动物在适应或习得过程中，在EB反应方面与对照组没有差异。然而，在消退过程中，损伤动物比对照动物表现出更多的EB CRs。两组动物的EMG CRs都很小。在训练的所有阶段，损伤动物的HR变化都比对照动物小，尽管所有动物的HR CRs都倾向于表现为心动过缓。由于LH损伤，在电击阈值或旷场活动方面未观察到差异。与对照动物相比，损伤动物的皮质和海马5-HT和NE浓度显著降低。这些发现是在前脑结构的中脑调节对注意力进行相位控制的框架内进行解释的；然而，不能排除介导脑干心脏控制的下行纤维的中断。
