Examining the effects of former cannabis use on cerebellum-dependent eyeblink conditioning in humans.
Examining the effects of former cannabis use on cerebellum-dependent eyeblink conditioning in humans.
复制标题
检查以前使用大麻对人类小脑依赖性眨眼调节的影响。
DOI：
10.1007/s00213-011-2556-1
复制
发表时间：
2012
影响因子：
3.4
通讯作者：
Skosnik,PatrickD
中科院分区：
文献类型：
--
作者：
Steinmetz,AdamB;Edwards,ChadR;Vollmer,JenniferM;Erickson,MollyA;O'Donnell,BrianF;Hetrick,WilliamP;Skosnik,PatrickD
先前对人类的研究表明，慢性大麻使用者表现出经典眨眼条件反射（EBC）的中断，这是一种已知依赖于小脑的联想学习形式。基于先前在动物中的工作，假设这些学习缺陷与大麻素受体（CB1R）下调有关。然而，目前尚不清楚停止使用大麻后是否会恢复小脑依赖性学习。方法因此，对前大麻使用者（n = 10）、当前大麻使用者（n = 10）和大麻初治对照组（n = 10）进行了评估，所有人都没有DSM-IV轴I或II障碍。利用标准延迟EBC程序，其中成对呈现条件刺激（CS;例如，音调）和共同终止的无条件刺激（US;例如，眼部空气抽吸），从而引发条件性眨眼反应（CR）。主要的依赖措施的百分比CR和CR潜伏期调节blocks.ResultsSimilarly以前的研究，目前的大麻用户表现出显着的障碍，在收购和时间的CR相比，控制。虽然前大麻用户显示完整的CR收购相比，控制，他们表现出显着受损（较短）CR潜伏期。在这两个大麻组，UR振幅没有不同的控制，表明正常的美国processing.ConclusionsThese数据表明，恢复功能已经发生的学习的CS-US协会，而准确的时间CR显示持久的损害。总之，这些结果表明，大量使用大麻可以破坏小脑内与时间相关的突触可塑性，即使在停止使用大麻之后。
RationalePrevious work in humans has shown that chronic cannabis users exhibit disruptions in classical eyeblink conditioning (EBC), a form of associative learning that is known to be dependent on the cerebellum. Based upon previous work in animals, it was hypothesized that these learning deficits were related to cannabinoid receptor (CB1R) downregulation. However, it remains unclear whether there is a recovery of cerebellum-dependent learning after the cessation of cannabis use.MethodsTherefore, former cannabis users (n=10), current cannabis users (n=10), and cannabis-naïve controls (n=10), all free of DSM-IV Axis-I or -II disorders, were evaluated. A standard delay EBC procedure was utilized in which paired presentations of a conditioned stimulus (CS; e.g., tone) and a co-terminating unconditioned stimulus (US; e.g., ocular airpuff) were administered, thus eliciting a conditioned eyeblink response (CR). The primary dependent measures were percentage of CRs and CR latency across conditioning blocks.ResultsSimilar to prior studies, current cannabis users exhibited marked impairments in both the acquisition and timing of CRs compared to controls. Although former cannabis users showed intact CR acquisition compared to controls, they exhibited significantly impaired (shorter) CR latencies. In both cannabis groups, UR amplitude did not differ from controls, indicating normal US processing.ConclusionsThese data suggest that a recovery of function has occurred for the learning of the CS–US association, while the accurate timing of the CR shows lasting impairments. Taken together, these results suggest that heavy cannabis use can disrupt timing-related synaptic plasticity within the cerebellum, even after the cessation of cannabis use.