Turgeon S M, Auerbach E A, Heller M A
Department of Psychology, Amherst College, MA 01002, USA.
Pharmacol Biochem Behav. 1998 Jun;60(2):553-8. doi: 10.1016/s0091-3057(98)00026-4.
The acute effects of a low dose of phencyclidine (PCP) and the delayed effects of a high dose of PCP on latent inhibition (LI) were assessed in a series of experiments using conditioned taste aversion paradigms. Each paradigm involved a preexposure phase in which water-deprived male rats were allowed access to either water (nonpreexposed; NPE) or 5% sucrose (preexposed; PE), followed by a conditioning phase in which animals were allowed access to sucrose and subsequently injected with the negative reinforcer lithium chloride, and a test phase in which animals were allowed access to both sucrose and water. LI was assessed by comparing the %-sucrose consumed in PE and NPE groups on the test day. The effects of low-dose PCP (2.5 mg/kg) were assessed by comparing LI in animals treated with vehicle or PCP 15 min prior to the onset of the preexposure and conditioning phases. A 4-day paradigm involved 2 days of preexposure followed by a day of conditioning and a test day. This paradigm produced comparable levels of LI in vehicle and PCP-treated animals. A 5-day extinction paradigm involved 2 days of preexposure followed by 2 days of conditioning and a test day. This paradigm abolished LI in vehicle and PCP-treated animals. A 3-day paradigm involved 1 day of preexposure followed by a day of conditioning and a test day. One day of preexposure induced a modified LI effect in both in vehicle and PCP-treated animals. The delayed effects of high dose PCP (8.6 mg/kg) were assessed by comparing LI in animals treated with vehicle or PCP 20 h prior to the onset of the preexposure and conditioning phases in the 4-day paradigm. PCP disrupted latent inhibition in this paradigm. The results are discussed in the context of their relevance to the ability for PCP to model schizophrenic symptomatology.
在一系列使用条件性味觉厌恶范式的实验中，评估了低剂量苯环己哌啶（PCP）的急性效应以及高剂量PCP对潜伏抑制（LI）的延迟效应。每个范式都包括一个预暴露阶段，在此阶段，剥夺水分的雄性大鼠可以接触水（未预暴露；NPE）或5%蔗糖（预暴露；PE），随后是一个条件化阶段，在此阶段，动物可以接触蔗糖，随后注射负性强化剂氯化锂，以及一个测试阶段，在此阶段，动物可以接触蔗糖和水。通过比较测试日PE组和NPE组消耗的蔗糖百分比来评估LI。通过比较在预暴露和条件化阶段开始前15分钟接受溶剂或PCP处理的动物的LI，评估低剂量PCP（2.5毫克/千克）的效应。一个4天的范式包括2天的预暴露，随后是1天的条件化和1天的测试。这个范式在接受溶剂和PCP处理的动物中产生了相当水平的LI。一个5天的消退范式包括2天的预暴露，随后是2天的条件化和1天的测试。这个范式消除了接受溶剂和PCP处理的动物的LI。一个3天的范式包括1天的预暴露，随后是1天的条件化和1天的测试。1天的预暴露在接受溶剂和PCP处理的动物中都诱导了一种改变的LI效应。通过比较在4天范式中预暴露和条件化阶段开始前20小时接受溶剂或PCP处理的动物的LI，评估高剂量PCP（8.6毫克/千克）的延迟效应。PCP在这个范式中破坏了潜伏抑制。将根据这些结果与PCP模拟精神分裂症症状的能力之间的相关性进行讨论。
