Wolthuis O L
Pharmacol Biochem Behav. 1981 Aug;15(2):247-55. doi: 10.1016/0091-3057(81)90184-2.
The effects of etiracetam, a structural analogue of piracetam, were investigated in rats on Y-maze discrimination acquisition, on open field behaviour, on one-trial passive avoidance learning and on shuttlebox acquisition and extinction. The results indicate that this drug significantly enhances acquisition and may improve retention without having any detectable effects on spontaneous behaviour, not even in very high doses (500 mg/kg IP). Sensitivity to footshock, measured as "flinch" thresholds, was not altered by etiracetam in doses of 25 or 100 mg/kg IP. For a shuttlebox task the effective dose-range lies between 20--30 mg/kg IP, provided pretreatment during 4 days is given. Without pretreatment, i.e. when the drug is only administered during the relatively fast acquisition in the shuttlebox, it was found that acquisition was not enhanced, but extinction of the acquired behaviour was significantly inhibited. The effects of etiracetam can be found at lower dose-levels than with piracetam and also in tests (passive avoidance, shuttlebox) in which piracetam has no or only marginal effects.
在大鼠身上研究了乙拉西坦（一种吡拉西坦的结构类似物）对Y型迷宫辨别学习、旷场行为、一次性被动回避学习以及穿梭箱学习和消退的影响。结果表明，这种药物能显著增强学习能力，可能改善记忆保持，且对自发行为没有任何可检测到的影响，即使在非常高的剂量（腹腔注射500毫克/千克）下也是如此。以“退缩”阈值衡量的对足部电击的敏感性，在腹腔注射25或100毫克/千克剂量的乙拉西坦时并未改变。对于穿梭箱任务，有效剂量范围在腹腔注射20 - 30毫克/千克之间，前提是进行4天的预处理。如果不进行预处理，即仅在穿梭箱中相对快速的学习过程中给药，发现学习能力并未增强，但已习得行为的消退受到显著抑制。与吡拉西坦相比，在更低的剂量水平就能发现乙拉西坦的作用，而且在吡拉西坦没有作用或仅有轻微作用的测试（被动回避、穿梭箱）中也能发现其作用。
