Land Cantey, Spear Norman E
Center for Developmental Psychobiology, Binghamton University, Binghamton, NY 13902, USA.
Int J Dev Neurosci. 2004 Aug-Oct;22(5-6):355-62. doi: 10.1016/j.ijdevneu.2004.04.008.
Adolescent rats and humans exhibit physiological, behavioral, and cognitive differences compared to their adult counterparts. These differences are apparent also in reactions to psychoactive drugs, such as ethanol. Recent studies have shown that though less sensitive to several behavioral indices of intoxication by ethanol, adolescent rats are more sensitive to the cognition-impairing effects of ethanol. Ethanol's effects, in the present experiment, were assessed in terms of a fear conditioning test not previously used in comparison of adult and adolescent Sprague-Dawley albino rats. Separate groups of both ages were given intraperitoneal (i.p.) ethanol before or after tone-shock conditioning. This task features a hippocampus-independent component, learned freezing to a tone, and a hippocampus-dependent component, learned freezing to context. Post-training ethanol had no effect on retention in either age, but pre-acquisition ethanol impaired adult learning more than adolescent learning, as indexed by the expression of fear at the test. Blood alcohol was equivalent in adolescents and adults at a dose that produced cognitive discrepancies. Unlike other reports, these experiments demonstrate that adolescents may not be more sensitive to ethanol's effects in all cases of learning.
与成年大鼠和人类相比，青春期大鼠和人类在生理、行为和认知方面存在差异。这些差异在对精神活性药物（如乙醇）的反应中也很明显。最近的研究表明，虽然青春期大鼠对乙醇中毒的几种行为指标不太敏感，但它们对乙醇的认知损害作用更敏感。在本实验中，乙醇的作用是根据一种恐惧条件测试来评估的，该测试以前未用于比较成年和青春期的斯普拉格-道利白化大鼠。将两个年龄组的大鼠分别在音调-电击条件反射之前或之后腹腔注射乙醇。这项任务具有一个不依赖海马体的成分，即对音调的习得性僵立，以及一个依赖海马体的成分，即对环境的习得性僵立。训练后注射乙醇对两个年龄组的记忆保持均无影响，但在测试中恐惧表达所显示的那样，习得前注射乙醇对成年大鼠学习的损害比对青春期大鼠学习的损害更大。在产生认知差异的剂量下，青少年和成年人的血液酒精含量相当。与其他报告不同，这些实验表明，在所有学习情况下，青少年可能并非对乙醇的作用都更敏感。
