Sipos M L, Nyby J G
Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA.
J Neuroendocrinol. 1998 Aug;10(8):577-86. doi: 10.1046/j.1365-2826.1998.00215.x.
This experiment examined whether testosterone proprionate (T) action in the medial preoptic area (MPO) would synergize with T action in the medial nucleus of the amygdala (AME) for the expression of androgen-dependent behaviors in house mice. Cannulae containing T were bilaterally implanted into the MPO, the AME, or both areas concurrently (MPO/AME) of castrated males. In addition, other castrates were implanted subcutaneously with empty Silastic capsules (BSIL) or Silastic capsules containing T (TSIL). All subjects were examined for the following androgen-dependent, male-typical behaviors: mounting, urinary scent marking, preference for female urine over male urine, preference for female over male conspecifics and ultrasonic mating vocalizations. MPO implants restored ultrasonic vocalizations and preference for females, but had little or no effect upon urine marking, mounting or preference for female urine. In contrast, AME implants were ineffective at restoring any of these male-typical behaviors. The combined MPO/AME implants were not more effective in restoring male-typical behaviors than MPO implants alone, thus providing no evidence for synergy in hormone action between these two brain areas. In general, castration (BSIL) resulted in low levels of all behaviors whereas systemic T replacement (TSIL) resulted in high levels of behavior, verifying the androgen-dependence of these behaviors. Group differences in male-typical behavior could not be accounted for by differences in general activity levels. Moreover, none of the brain-implanted groups had larger seminal vesicles than those of the BSIL. Thus, when the brain implants affected behavior, they most probably did so through their effects within the brain. Although the AME is a target for steroid hormones and is an important area for the expression of male-typical behaviors, intracranial T implants into the AME did not demonstrate a role for androgen in the AME in restoring male-typical behaviors in castrated mice.
本实验研究了丙酸睾酮（T）在内侧视前区（MPO）的作用是否会与T在杏仁核内侧核（AME）的作用协同，以促进家鼠雄激素依赖行为的表达。将含有T的套管双侧植入去势雄性小鼠的MPO、AME或同时植入这两个区域（MPO/AME）。此外，其他去势小鼠皮下植入空的硅橡胶胶囊（BSIL）或含T的硅橡胶胶囊（TSIL）。检查所有受试对象的以下雄激素依赖的雄性典型行为：爬跨、尿液气味标记、对雌性尿液而非雄性尿液的偏好、对雌性而非雄性同种个体的偏好以及超声交配叫声。MPO植入恢复了超声叫声和对雌性的偏好，但对尿液标记、爬跨或对雌性尿液的偏好几乎没有影响。相比之下，AME植入对恢复这些雄性典型行为均无效。联合的MPO/AME植入在恢复雄性典型行为方面并不比单独的MPO植入更有效，因此没有证据表明这两个脑区之间存在激素作用协同效应。一般来说，去势（BSIL）导致所有行为水平较低，而全身T替代（TSIL）导致行为水平较高，证实了这些行为对雄激素的依赖性。雄性典型行为的组间差异不能用一般活动水平的差异来解释。此外，没有一个脑植入组的精囊比BSIL组的大。因此，当脑植入影响行为时，它们很可能是通过在脑内的作用来实现的。尽管AME是类固醇激素的作用靶点，也是雄性典型行为表达的重要区域，但颅内T植入AME并未显示雄激素在AME中对恢复去势小鼠雄性典型行为起作用。
