Wijayawardhane Nayana, Shonesy Brian C, Vaithianathan Thirumalini, Pandiella Noemi, Vaglenova Julia, Breese Charles R, Dityatev Alexander, Suppiramaniam Vishnu
Department of Pharmacal Sciences, 401 Walker Building, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA.
Neurobiol Dis. 2008 Jan;29(1):81-91. doi: 10.1016/j.nbd.2007.08.001. Epub 2007 Aug 14.
Ethanol-induced damage in the developing hippocampus may result in cognitive deficits such as those observed in fetal alcohol spectrum disorder (FASD). Cognitive deficits in FASD are partially mediated by alterations in glutamatergic synaptic transmission. Recently, we reported that synaptic transmission mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) is impaired following fetal ethanol exposure. This finding led us to develop a rational approach for the treatment of alcohol-related cognitive deficits using aniracetam, an allosteric AMPAR modulator. In the present study, 28 to 34-day-old rats exposed to ethanol in utero were treated with aniracetam, and subsequently exhibited persistent improvement in mEPSC amplitude, frequency, and decay time. Furthermore, these animals expressed positive changes in synaptic single channel properties, suggesting that aniracetam ameliorates prenatal ethanol-induced deficits through modifications at the single channel level. Specifically, single channel open probability, conductance, mean open and closed times, and the number and burst duration were positively affected. Our findings emphasize the utility of compounds which slow the rate of deactivation and desensitization of AMPARs such as aniracetam.
乙醇对发育中的海马体造成的损伤可能会导致认知缺陷,如胎儿酒精谱系障碍(FASD)中观察到的那些缺陷。FASD中的认知缺陷部分是由谷氨酸能突触传递的改变介导的。最近,我们报道胎儿暴露于乙醇后,由α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体(AMPARs)介导的突触传递受损。这一发现促使我们开发一种合理的方法,使用变构AMPAR调节剂茴拉西坦来治疗与酒精相关的认知缺陷。在本研究中,对28至34日龄子宫内暴露于乙醇的大鼠用茴拉西坦进行治疗,随后这些大鼠的微小兴奋性突触后电流(mEPSC)幅度、频率和衰减时间持续改善。此外,这些动物在突触单通道特性方面表现出积极变化,表明茴拉西坦通过在单通道水平上的修饰改善了产前乙醇诱导的缺陷。具体而言,单通道开放概率、电导、平均开放和关闭时间以及数量和爆发持续时间均受到积极影响。我们的研究结果强调了像茴拉西坦这样能减缓AMPARs失活和脱敏速率的化合物的效用。