McDermott J L, Kreutzberg J D, Liu B, Dluzen D E
Department of Medicine, Edwin Shaw Hospital, Akron, Ohio 44312.
Horm Behav. 1994 Mar;28(1):16-28. doi: 10.1006/hbeh.1994.1002.
In Experiment I, castrated male and female CD-1 mice +/- estradiol benzoate (EB) treatment were tested for their performance on a skilled sensorimotor task consisting of walking across beams of varying widths (6, 9, 12, and 21 mm). To evaluate whether behavioral performance was related to nigrostriatal dopaminergic function, tissue dopamine concentrations were determined from the corpus striatum as well as the hypothalamus and olfactory tubercle. In general, sensorimotor performance improved for all treatment conditions as the beam width increased. Castrated male mice treated with oil vehicle showed the worst performance as indicated by significantly greater amounts of time to cross the beam. Treatment of castrated males with EB significantly improved their performance. Performance of the castrated females was not changed by EB treatment and was similar to that observed with the castrated + EB males. Significant gender differences in dopamine concentrations (female > male) were obtained in the corpus striatum, as well as the olfactory tubercle and hypothalamus. Dopamine levels were unaltered by EB treatment. In Experiment II, behavioral and neurochemical determinations were directly compared between castrated and intact male mice. Behavioral performance of castrates was significantly reduced compared to intact males. No differences in dopamine concentrations were obtained between these two groups; however, the hypothalamic dopamine/DOPAC ratio of castrates was significantly greater than that of intact male mice. These results demonstrate significant modulatory effects of EB in castrated male, but not female, mice upon sensorimotor performance and indicate that this task may provide an effective means to partial out modulatory effects of gonadal steroid hormones upon skilled sensorimotor performance. When the data of Experiments I and II are combined, it appears that the basis of this sensorimotor deficit in the males is the absence of gonadal steroid hormones. In addition, these results reveal significant gender differences in various dopaminergic systems in these mice.
在实验I中，对接受或不接受苯甲酸雌二醇（EB）处理的去势雄性和雌性CD-1小鼠进行了一项精细的感觉运动任务测试，该任务包括走过不同宽度（6、9、12和21毫米）的横梁。为了评估行为表现是否与黑质纹状体多巴胺能功能有关，测定了纹状体以及下丘脑和嗅结节中的组织多巴胺浓度。一般来说，随着横梁宽度增加，所有处理条件下的感觉运动表现均有所改善。用油性赋形剂处理的去势雄性小鼠表现最差，穿过横梁的时间明显更长。用EB处理去势雄性小鼠可显著改善其表现。EB处理对去势雌性小鼠的表现没有影响，其表现与接受EB处理的去势雄性小鼠相似。在纹状体、嗅结节和下丘脑中，多巴胺浓度存在显著的性别差异（雌性>雄性）。EB处理对多巴胺水平没有影响。在实验II中，直接比较了去势和完整雄性小鼠的行为和神经化学测定结果。与完整雄性小鼠相比，去势小鼠的行为表现显著降低。这两组之间的多巴胺浓度没有差异；然而，去势小鼠下丘脑多巴胺/二羟基苯乙酸（DOPAC）比值显著高于完整雄性小鼠。这些结果表明，EB对去势雄性小鼠而非雌性小鼠的感觉运动表现具有显著的调节作用，并表明该任务可能提供一种有效的方法来区分性腺类固醇激素对精细感觉运动表现的调节作用。当将实验I和实验II的数据结合起来时，似乎雄性小鼠这种感觉运动缺陷的基础是缺乏性腺类固醇激素。此外，这些结果揭示了这些小鼠各种多巴胺能系统中存在显著的性别差异。
