Adult rats emit ultrasonic vocalizations (USVs) related to their affective states, potentially providing information about their subjective experiences during behavioral neuroscience experiments. If so, USVs might provide an important link between invasive animal preclinical studies and human studies in which subjective states can be readily queried. Here, we induced USVs in male and female Long Evans rats using acute amphetamine (2 mg/kg), and asked how reversibly inhibiting nucleus accumbens neurons using designer receptors exclusively activated by designer drugs (DREADDs) impacts USV production. We analyzed USV characteristics using “Deepsqueak” software, and manually categorized detected calls into four previously defined subtypes. We found that systemic administration of the DREADD agonist clozapine-n-oxide, relative to vehicle in the same rats, suppressed the number of frequency-modulated and trill-containing USVs without impacting high frequency, unmodulated (flat) USVs, nor the small number of low-frequency USVs observed. Using chemogenetics, these results thus confirm that nucleus accumbens neurons are essential for production of amphetamine-induced frequency-modulated USVs. They also support the premise of further investigating the characteristics and subcategories of these calls as a window into the subjective effects of neural manipulations, with potential future clinical applications.

中文翻译：

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伏核化学遗传学抑制可抑制雄性和雌性大鼠中安非他明诱导的超声波发声

成年老鼠发出与其情感状态相关的超声波发声（USV），可能提供有关其在行为神经科学实验中主观体验的信息。如果是这样，无人水面艇可能会在侵入性动物临床前研究和人类研究之间提供重要的联系，在人类研究中可以很容易地查询主观状态。在这里，我们使用急性安非他明（2 mg/kg）在雄性和雌性 Long Evans 大鼠中诱导 USV，并询问使用仅由设计药物激活的设计受体（DREADD）可逆地抑制伏隔核神经元如何影响 USV 的产生。我们使用“Deepsqueak”软件分析了 USV 特征，并将检测到的呼叫手动分类为四个先前定义的子类型。我们发现，相对于同一大鼠中的媒介物，全身施用 DREADD 激动剂氯氮平-n-氧化物可抑制调频和含有颤音的 USV 数量，而不影响高频、未调制（平坦）USV，也不影响少量 USV。观察到的低频 USV 的数量。利用化学遗传学，这些结果证实伏隔核神经元对于安非他明诱导的调频 USV 的产生至关重要。他们还支持进一步研究这些调用的特征和子类别的前提，作为了解神经操作的主观影响的窗口，并具有未来潜在的临床应用。