Abstract:
Sexual stimulation triggers changes in female physiology and behavior, including sexual satiety and preparing the uterus for pregnancy. Serotonin is an important regulator of reproductive physiology and sexual receptivity, but the relationship between sexual stimulation and serotonin neural activity in females is poorly understood. Here, we investigated dorsal raphe serotonin neural activity in females during sexual behavior. We found that serotonin neural activity in mating females peaked specifically upon male ejaculation, and remained elevated above baseline until disengagement. Artificial intravaginal mechanical stimulation was sufficient to elicit increased 5-HT neural activity but the delivery of ejaculatory fluids was not. Distal penis erectile enlargement (\"penile cupping\") at ejaculation and forceful expulsion of ejaculatory fluid each provided sufficient mechanical stimulation to elicit serotonin neuron activation. Our study identifies a female ejaculation-specific signal in a major neuromodulatory system and shows that intravaginal mechanosensory stimulation is necessary and sufficient to drive this signal.
摘要:
性刺激会引发女性生理和行为的变化,包括性饱腹感和准备子宫怀孕。5-羟色胺是生殖生理和性接受的重要调节因子,但是女性的性刺激与5-羟色胺神经活动之间的关系知之甚少。这里,我们调查了女性在性行为过程中的背侧5-羟色胺神经活动。我们发现交配雌性中的5-羟色胺神经活性在雄性射精时达到峰值,并保持高于基线,直到脱离接触。人工阴道内机械刺激足以引起5-HT神经活性增加,但射精液的输送却不能。射精时阴茎远端勃起增大(“阴茎拔罐”)和射精液的强力排出均提供足够的机械刺激以引起5-羟色胺神经元激活。我们的研究确定了主要神经调节系统中女性射精特异性信号,并表明阴道内机械感觉刺激对于驱动该信号是必要且足够的。