Boyd S K, Moore F L
Department of Zoology, Oregon State University, Corvallis 97331.
Horm Behav. 1990 Mar;24(1):128-38. doi: 10.1016/0018-506x(90)90032-s.
The behavioral effects of GABA analogs were investigated to determine whether GABAergic neurotransmission is involved in the stress-induced inhibition of masculine sexual behaviors in rough-skinned newts (Taricha granulosa). Injections of bicuculline, a GABA antagonist, stimulated male sexual behaviors in a dose-dependent fashion, and the minimum effective dose was 40-fold less when administered centrally rather than systemically, suggesting a central nervous system site of action. Injections of muscimol, a GABA agonist, suppressed reproductive behaviors in male newts, and this inhibition lasted at least 5 hr and was proportional to the dose of muscimol administered. The inhibitory effects of muscimol on newt sexual behaviors could be reversed by a single 100-microgram ip injection of arginine vasotocin. The inhibitory effects of confinement stress or corticosterone (CS) injections on newt sexual behaviors were blocked by pretreatment of newts with mercaptopropionic acid, a blocker of GABA synthesis. As well, bicuculline prevented the inhibition of sexual behavior induced by CS injection. These results support the conclusion that, in a male amphibian, the GABAergic system is involved in the inhibitory mechanisms regulating sexual behaviors and that CS mediates the stress-induced inhibition of sexual behaviors through the GABAergic system.
研究了γ-氨基丁酸（GABA）类似物的行为效应，以确定GABA能神经传递是否参与了糙皮蝾螈（Taricha granulosa）应激诱导的雄性性行为抑制。注射GABA拮抗剂荷包牡丹碱以剂量依赖的方式刺激雄性性行为，并且当通过中枢给药而非全身给药时，最小有效剂量要低40倍，这表明其作用部位在中枢神经系统。注射GABA激动剂蝇蕈醇可抑制雄性蝾螈的生殖行为，这种抑制作用至少持续5小时，并且与所给予的蝇蕈醇剂量成正比。单次腹腔注射100微克精氨酸血管催产素可逆转蝇蕈醇对蝾螈性行为的抑制作用。用GABA合成阻滞剂巯基丙酸预处理蝾螈，可阻断禁闭应激或注射皮质酮（CS）对蝾螈性行为的抑制作用。同样，荷包牡丹碱可阻止CS注射诱导的性行为抑制。这些结果支持以下结论：在雄性两栖动物中，GABA能系统参与调节性行为的抑制机制，并且CS通过GABA能系统介导应激诱导的性行为抑制。
