Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, QC, Canada.
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, QC, Canada.
Horm Behav. 2019 Mar;109:1-9. doi: 10.1016/j.yhbeh.2019.01.005. Epub 2019 Jan 30.
Fifty-kHz ultrasonic vocalizations (USVs) are emitted by adult rats during appetitive phases of behavior in response to stimuli thought to be associated with a positive affective state. In particular, 50-kHz USVs with rapid frequency oscillations, known as trills and flat-trills, in which these oscillations are flanked by a monotonic portion, are together positively correlated with appetitive behaviors such as rough and tumble play, drug and natural reward, and mating. Female rats produce 50-kHz USVs during a variety of sexual contexts, yet data are still vague as female sexual behavior is seldom studied on its own. Distributed clitoral stimulation (CLS) offers a unique approach to investigating female 50-kHz USVs as it mimics stimulation received during mating. Although CLS induces a sexual reward state, it is unknown whether CLS elicits trills and flat-trills. We addressed this question using eight ovariectomized rats, we investigated whether ovarian hormones augmented these call subtypes in response to CLS. The combined and separate effects of estradiol benzoate (EB) and progesterone (P), and oil vehicle were assessed through comparison of these call subtypes between CLS and inter-CLS interval. We found that CLS with EB + P significantly increased call duration and rate, lowered peak frequency, and widened the bandwidth of trills. Flat-trills showed a similar pattern except for call duration. Call distribution during the CLS and inter-CLS interval suggest that trill and flat-trills may be indicative of both anticipatory and sexual reward.
五十千赫兹超声发声（USVs）是成年大鼠在行为的欲望阶段发出的，以响应被认为与积极情绪状态相关的刺激。特别是，具有快速频率振荡的 50-kHz USVs，称为颤音和扁颤音，其中这些振荡被单调部分包围，与欲望行为如粗野游戏、药物和自然奖励以及交配一起呈正相关。雌性大鼠在各种性环境中产生 50-kHz USVs，但由于很少单独研究雌性性行为，因此数据仍然模糊。分布式阴蒂刺激（CLS）提供了一种独特的方法来研究雌性 50-kHz USVs，因为它模拟了在交配期间接受的刺激。尽管 CLS 诱导性奖励状态，但尚不清楚 CLS 是否会引发颤音和扁颤音。我们使用 8 只去卵巢大鼠来解决这个问题，我们研究了卵巢激素是否会在 CLS 刺激下增强这些叫声亚型。通过比较 CLS 和 CLS 间隔之间的这些叫声亚型，评估雌二醇苯甲酸酯（EB）和孕酮（P）以及油载体的联合和单独作用。我们发现，EB+P 的 CLS 显著增加了叫声的持续时间和速率，降低了峰值频率，并扩大了颤音的带宽。扁颤音除了叫声持续时间外，表现出类似的模式。CLS 和 CLS 间隔期间的叫声分布表明，颤音和扁颤音可能同时预示着预期和性奖励。
