Kritzer M F, McLaughlin P J, Smirlis T, Robinson J K
Department of Neurobiology and Behavior, SUNY Stony Brook, Stony Brook, New York, 11794-5230, USA.
Horm Behav. 2001 Mar;39(2):167-74. doi: 10.1006/hbeh.2001.1645.
Recent studies have shown that chronic gonadectomy increases the density of dopaminergic axons in prefrontal but not sensorimotor cortices in adult male rats. Since supranormal prefrontal cortical dopamine stimulation is known to impair rats' performance in T-maze delayed alternation paradigms, we tested whether long-term gonadectomy might also impair T-maze performance. For comparison, sensorimotor functions were also assessed. Adult male rats were gonadectomized and placebo-, estradiol-, or testosterone propionate-treated or were sham operated and placebo-treated. Four weeks after surgery, the subjects were tested using a rotorod apparatus and in the acquisition of a T-maze delayed alternation paradigm. Gonadectomized placebo-treated and estradiol-treated rats took significantly longer to acquire the T-maze rule than controls, and gonadectomized, testosterone-treated rats acquired the task within the same time frame as controls. No group differences were detected in rotorod performance. Thus, chronic gonadectomy induced testosterone-sensitive, estradiol-insensitive acquisition deficits in a spatial learning task but had no demonstrable effects on the sensorimotor functions tested.
最近的研究表明，成年雄性大鼠长期去势会增加前额叶而非感觉运动皮层中多巴胺能轴突的密度。由于已知超常的前额叶皮层多巴胺刺激会损害大鼠在T迷宫延迟交替范式中的表现，我们测试了长期去势是否也会损害T迷宫表现。为作比较，还评估了感觉运动功能。成年雄性大鼠接受去势手术，并分别用安慰剂、雌二醇或丙酸睾酮处理，或进行假手术并给予安慰剂处理。术后四周，使用转棒仪对实验对象进行测试，并让其学习T迷宫延迟交替范式。去势后接受安慰剂处理和雌二醇处理的大鼠比对照组花费更长时间来掌握T迷宫规则，而去势后接受睾酮处理的大鼠与对照组在相同时间内完成了任务。在转棒仪表现方面未检测到组间差异。因此，长期去势在空间学习任务中诱导了对睾酮敏感、对雌二醇不敏感的学习缺陷，但对所测试的感觉运动功能没有明显影响。
