Stimulation of dopamine receptors in the paraventricular nucleus of the hypothalamus of male rats induces penile erection and increases extra-cellular dopamine in the nucleus accumbens: Involvement of central oxytocin
Stimulation of dopamine receptors in the paraventricular nucleus of the hypothalamus of male rats induces penile erection and increases extra-cellular dopamine in the nucleus accumbens: Involvement of central oxytocin
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DOI：
10.1016/j.neuropharm.2006.10.019
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发表时间：
2007-03
影响因子：
4.7
通讯作者：
S. Succu;F. Sanna;T. Melis;A. Boi;A. Argiolas;M. R. Melis
中科院分区：
文献类型：
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作者：
S. Succu;F. Sanna;T. Melis;A. Boi;A. Argiolas;M. R. Melis
在雄性大鼠下丘脑室旁核注射促勃起剂量的混合多巴胺受体激动剂阿朴吗啡和选择性多巴胺D4受体激动剂PD-168077(N-[4-(2-cyanophenyl)piperazin-1-ylmethyl]-3-methylbenzamide马来酸对伏核透析液中细胞外多巴胺及其主要代谢物3，4-二羟基苯乙酸浓度的影响。正如预期的那样，阿朴吗啡(0.1μg)和PD-168077(0.1μg)诱导阴茎勃起，同时通过脑内微透析法测定，伏隔核壳透析液中细胞外多巴胺和DOPAC浓度增加。在阿朴吗啡诱导下，选择性D2/D3受体拮抗剂拉氯普利(1μg)可使上述效应降低80%，而多巴胺D4受体拮抗剂L-745,870(1μg)仅可使其减弱40~45%。在PD-168077诱导下，L-745,870(1μg)可使上述效应降低80%以上，而雷氯普利仅能降低35-40%。侧脑室注射催产素受体拮抗剂d(CH_2)_5-Tyr(Me)_2-Orn_8-Vasotoin(1μ_g)后，无论是用什么多巴胺激动剂来诱导阴茎勃起，伏隔核透析液中的促勃起效应和伴随的多巴胺和DOPAC浓度的增加几乎被完全消除。本结果提示，刺激室旁核多巴胺受体(主要是D2~D4亚型)可诱导脑区催产素的释放，从而影响中脑边缘多巴胺能神经元的活动，从而介导性活动的食欲和增强效应。这为催产素在神经回路中的作用提供了证据，神经回路将控制性行为(如阴茎勃起)的消费方面的神经通路的活动与控制性动机和性唤起的神经通路结合在一起。
The effect of a pro-erectile dose of apomorphine, a mixed dopamine receptor agonist, and of PD-168077 (N-[4-(2-cyanophenyl)piperazin-1-ylmethyl]-3-methylbenzamide maleate), a selective dopamine D4 receptor agonist, injected into the paraventricular nucleus of the hypothalamus on the concentration of extra-cellular dopamine and its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the dialysate from the nucleus accumbens was studied in male rats. As expected, apomorphine (0.1μg) and PD-168077 (0.1μg) induced penile erection episodes, which occurred concomitantly to an increase in extra-cellular dopamine and DOPAC concentration in the dialysate from the shell of the nucleus accumbens, as measured by intracerebral microdialysis. When induced by apomorphine, these effects were reduced by 80% by raclopride, a selective D2/D3 receptor antagonist (1μg) and only by 40–45% by L-745,870 (1μg), a selective dopamine D4 receptor antagonist. When induced by PD-168077, these effects were reduced by more than 80% by L-745,870 (1μg), but only by 35–40% by raclopride. Irrespective of the dopamine agonist used to induce penile erection, the pro-erectile effect and the concomitant increase in dopamine and DOPAC concentration in the nucleus accumbens dialysate were almost completely abolished by d(CH2)5Tyr(Me)2-Orn8-vasotocin(1μg), a potent oxytocin receptor antagonist, given into the lateral ventricles. The present results suggest that stimulation of dopamine receptors (mainly of the D2 to D4 subtype) in the paraventricular nucleus induces the release of oxytocin in brain areas that influence the activity of mesolimbic dopaminergic neurons mediating the appetitive and reinforcing effects of sexual activity. This provides evidence for a role of oxytocin in neural circuits that integrate the activity of neural pathways controlling the consummatory aspects of sexual behaviour (e.g., penile erection) with those controlling sexual motivation and sexual arousal.