Adams J U, Efferen T R, Duncan E J, Rotrosen J
Mental Health Research, New York Harbor Department of Veterans Affairs Health Care System, Department of Psychiatry, New York University School of Medicine, NY 10010, USA.
Pharmacol Biochem Behav. 2001 Apr;68(4):753-9. doi: 10.1016/s0091-3057(01)00478-6.
Prepulse inhibition (PPI) of startle is a sensorimotor gating task in which a low-intensity acoustic stimulus presented prior to a high-intensity, startle-eliciting stimulus can attenuate the acoustic startle response (ASR). Previous studies on startle reactivity in cocaine-withdrawn rats have found minimal changes; the present study extends this work to the gating of ASR. In Experiment 1, rats were injected daily with either saline or cocaine (30 mg/kg i.p.) for 2 weeks. ASR and PPI were measured prior to, and at 3- and 14-day withdrawal from, the chronic treatment. No effect of cocaine treatment was found on either measure. In Experiment 2, treatment was extended to 8 weeks, and an earlier withdrawal time point (1 day) was added. Rats treated with cocaine for 8 weeks exhibited lower startle reactivity during withdrawal compared with saline-treated controls. PPI did not differ between treatment groups. Thus, extended chronic treatment with cocaine rendered significant effects on startle responsivity. Further, this finding mirrors the blunted ASR exhibited in chronic cocaine users [Neuropsychopharmacology 22 (2000) 89.].
惊吓反应的前脉冲抑制（PPI）是一种感觉运动门控任务，其中在高强度的惊吓诱发刺激之前呈现的低强度听觉刺激可减弱听觉惊吓反应（ASR）。先前关于可卡因戒断大鼠惊吓反应性的研究发现变化极小；本研究将这项工作扩展到ASR的门控方面。在实验1中，大鼠每天注射生理盐水或可卡因（30毫克/千克腹腔注射），持续2周。在慢性治疗前、停药3天和14天时测量ASR和PPI。未发现可卡因治疗对任何一项测量指标有影响。在实验2中，治疗延长至8周，并增加了一个更早的停药时间点（1天）。与生理盐水处理的对照组相比，用可卡因治疗8周的大鼠在停药期间表现出较低的惊吓反应性。各治疗组之间的PPI没有差异。因此，可卡因的长期慢性治疗对惊吓反应性产生了显著影响。此外，这一发现反映了慢性可卡因使用者中表现出的ASR迟钝[《神经精神药理学》22（2000）89]。
