Sandner Guy, Canal Nathalie Monique, Brandão Marcus Lira
I.N.S.E.R.M. U405, Faculté de médecine, Université Louis Pasteur 11, Rue Humann, 67085 Strasbourg-Cedex, France.
Behav Brain Res. 2002 Jan 22;128(2):161-8. doi: 10.1016/s0166-4328(01)00273-x.
Prepulse inhibition (PPI) of the startle reaction to a strong sound is the reduction of this reaction elicited by a weak stimulus, a tone for example, when it precedes the startling sound. Its pharmacological sensitivity has been used to characterize antipsychotic drugs. Not much is known about the level of action of such drugs in the neuronal network involved in PPI. In the present study, evoked potentials from two key structures, the inferior colliculus (IC) and the caudal pontine reticular nucleus (PnC), were obtained in freely moving rats during standard startle and PPI tests, under ketamine (5 mg/kg) or apomorphine (0.5 mg/kg). In the IC, the potential evoked by the noise did not vary whether tested in basic or PPI conditions. Only minor changes were elicited by the drugs. In the PnC, the noise elicited an evoked potential that was reduced under PPI conditions. This alteration of the evoked potential was reversed by ketamine. The results obtained with apomorphine were not homogeneous either when considering the behavioral or the electrophysiological results.
对强声惊吓反应的前脉冲抑制（PPI）是指在惊吓声之前出现的弱刺激（例如一个音调）所引发的该反应的减弱。其药理学敏感性已被用于表征抗精神病药物。对于此类药物在参与PPI的神经网络中的作用水平，人们了解得并不多。在本研究中，在氯胺酮（5毫克/千克）或阿扑吗啡（0.5毫克/千克）作用下，于标准惊吓和PPI测试期间，在自由活动的大鼠身上获取了来自两个关键结构——下丘（IC）和脑桥尾侧网状核（PnC）的诱发电位。在IC中，无论在基础条件还是PPI条件下进行测试，噪声诱发的电位均无变化。药物仅引起了微小变化。在PnC中，噪声诱发了一种诱发电位，该电位在PPI条件下降低。氯胺酮可逆转这种诱发电位的改变。考虑行为学或电生理学结果时，阿扑吗啡所获得的结果也不一致。
