Graham S J, Scaife J C, Balboa Verduzco A M, Langley R W, Bradshaw C M, Szabadi E
Division of Psychiatry, University of Nottingham, Nottingham, UK.
J Psychopharmacol. 2004 Jun;18(2):173-80. doi: 10.1177/0269881104042615.
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (PPI). Here, we report the effects of the 'atypical' antipsychotic drug quetiapine and the 'conventional' antipsychotic haloperidol on these responses. Sixteen males (aged 19-38 years) participated in four sessions at 7-day intervals, in which they received quetiapine 12.5 mg, quetiapine 25 mg, haloperidol 3 mg and placebo, according to a balanced double-blind design. Electromyographic (EMG) responses of the orbicularis oculi muscle and N1/P2 auditory evoked potentials were recorded in a 20-min session, 2 h after treatment. Subjects received 40 trials in which 1-kHz sounds were presented: (i) 40 ms, 115 dB ('pulse alone' trials) and (ii) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse' trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage PPI was calculated. Serum prolactin was measured after each treatment, and autonomic (heart rate, blood pressure, salivation) and psychological (visual analogue self-ratings of mood and alertness, critical flicker fusion frequency) measures were taken before and after each treatment. Quetiapine 12.5 mg and 25 mg significantly reduced the amplitude of the EMG response without altering its inhibition by prepulses; haloperidol had no effect on EMG response amplitude or PPI. Neither drug affected N1/P2 amplitude or PPI of this response. Quetiapine, but not haloperidol, reduced subjective alertness and critical flicker fusion frequency. Haloperidol, but not quetiapine, elevated serum prolactin level. The ability of quetiapine to attenuate the startle response may reflect its sedative action.
当在引发惊吓的刺激（预脉冲抑制，PPI）前30 - 500毫秒呈现一个短暂的低强度刺激时，眼轮匝肌对突然的大声响（听觉惊吓反应）的收缩以及听觉诱发电位的N1/P2成分都会减弱。在此，我们报告了“非典型”抗精神病药物喹硫平和“传统”抗精神病药物氟哌啶醇对这些反应的影响。16名男性（年龄在19 - 38岁之间）每隔7天参加四个疗程，按照平衡双盲设计，他们分别接受12.5毫克喹硫平、25毫克喹硫平、3毫克氟哌啶醇和安慰剂。在治疗2小时后的20分钟疗程中记录眼轮匝肌的肌电图（EMG）反应和N1/P2听觉诱发电位。受试者接受40次试验，其中呈现1千赫的声音：（i）40毫秒，115分贝（“单独脉冲”试验）和（ii）40毫秒，85分贝，在120毫秒后接着是40毫秒，115分贝（“预脉冲/脉冲”试验）。EMG反应和N1/P2电位的平均幅度来自单独脉冲试验，并且在每种情况下计算百分比PPI。每次治疗后测量血清催乳素，并且在每次治疗前后进行自主神经（心率、血压、唾液分泌）和心理（情绪和警觉性的视觉模拟自评、临界闪烁融合频率）测量。12.5毫克和25毫克喹硫平显著降低了EMG反应的幅度，而不改变其被预脉冲抑制的情况；氟哌啶醇对EMG反应幅度或PPI没有影响。两种药物都不影响该反应的N1/P2幅度或PPI。喹硫平，但不是氟哌啶醇，降低了主观警觉性和临界闪烁融合频率。氟哌啶醇，但不是喹硫平，提高了血清催乳素水平。喹硫平减弱惊吓反应的能力可能反映了其镇静作用。
