Behavioral Neuroscience, Experimental and Biological Psychology, Philipps-University of Marburg, Gutenbergstr. 18, 35032, Marburg, Germany.
Department of Pharmacology and Therapeutics, McGill University, McIntyre Medical Building Rm. 1325, 3655 Promenade Sir William Osler, Montreal, QC, H3G 1Y6, Canada.
Psychopharmacology (Berl). 2018 Aug;235(8):2435-2445. doi: 10.1007/s00213-018-4942-4. Epub 2018 Jun 16.
Adult rat 22-kHz vocalizations are often associated with alarm or distress, whereas a subset of 50-kHz calls is preferentially emitted in response to amphetamine and other rewarding stimuli. Whether any 50-kHz calls reflect anxiety is unknown.
To determine the effects of anxiogenic drugs on 50-kHz call rate and call subtype profile, in comparison with D-amphetamine.
Adult male rats received systemic amphetamine (1 mg/kg) three times several days before testing. Ultrasonic vocalizations were then recorded after acute intraperitoneal injection of amphetamine or one of five anxiogenic drugs: yohimbine (2.5 mg/kg), N-methyl-β-carboline-3-carboxamide (FG 7142, 5 mg/kg), pentylenetetrazol (PTZ, 20 mg/kg), m-chlorophenylpiperazine (mCPP, 1 mg/kg), caffeine (25 mg/kg), or vehicle.
The duration of immobility was increased by FG 7142, PTZ, and mCPP; this measure was unchanged by yohimbine and reduced by the locomotor stimulant drugs amphetamine and caffeine. Conversely, the 50-kHz call rate was reduced by FG 7142, PTZ and mCPP, and increased by caffeine and amphetamine. Overall, the most common 50-kHz call subtypes were flat, trill, step-up, and complex. Consistent with previous reports, amphetamine increased the relative prevalence of trill calls while reducing the relative prevalence of flat calls. Yohimbine and caffeine reduced flat call prevalence, whereas mCPP reduced trill call prevalence. No other shifts in the call profile were observed, and no anxiogenic drug induced 22-kHz calls.
Anxiogenic drugs, as a class, did not uniformly alter the 50-kHz call rate or subtype profile. Amphetamine-induced effects on 50-kHz call rate and profile do not reflect anxiety.
成年大鼠的 22-kHz 叫声通常与警报或痛苦有关，而亚组的 50-kHz 叫声则优先响应安非他命和其他奖赏刺激而发出。任何 50-kHz 叫声是否反映焦虑尚不清楚。
确定焦虑药物对 50-kHz 叫声率和叫声亚型谱的影响，与安非他命进行比较。
成年雄性大鼠在测试前几天接受三次系统安非他命（1mg/kg）。然后在急性腹膜内注射安非他命或五种焦虑药物之一后记录超声波叫声：育亨宾（2.5mg/kg）、N-甲基-β-咔啉-3-羧酸（FG 7142，5mg/kg）、戊四唑（PTZ，20mg/kg）、m-氯苯基哌嗪（mCPP，1mg/kg）、咖啡因（25mg/kg）或载体。
FG 7142、PTZ 和 mCPP 增加了不动时间；育亨宾和运动兴奋剂药物安非他命和咖啡因未改变此测量值，而降低了该测量值。相反，50-kHz 叫声率被 FG 7142、PTZ 和 mCPP 降低，被咖啡因和安非他命增加。总体而言，最常见的 50-kHz 叫声亚型是平坦、颤音、递增和复杂。与先前的报告一致，安非他命增加了颤音叫声的相对流行度，同时降低了平坦叫声的相对流行度。育亨宾和咖啡因降低了平坦叫声的流行度，而 mCPP 降低了颤音叫声的流行度。未观察到叫声特征的其他变化，也没有任何焦虑药物引起 22-kHz 叫声。
焦虑药物作为一类药物，并未均匀改变 50-kHz 叫声率或叫声亚型谱。安非他命对 50-kHz 叫声率和特征的影响并不反映焦虑。
