Drachman D A, Noffsinger D, Sahakian B J, Kurdziel S, Fleming P
Neurobiol Aging. 1980 Summer;1(1):39-43. doi: 10.1016/0197-4580(80)90022-6.
Impairment of cholinergic neural function has been proposed as a cause of memory and cognitive (M/C) disorders of the aged since with cholinergic blockade young subjects show the M/C pattern of the elderly. To validate this hypothesis, we compared the performance of young normal subjects, young scopolamine-treated subjects, and aged subjects, using a different type of behavioral task, a dichotic listening test, which primarily measures neural channel capacity. With simultaneous dichotic presentation, undrugged young subjects reported both messages correctly in 35% of trials. Aged subjects scored double-correct responses in only 19% of trials, a highly significant difference (p less than 0.001). Following treatment with 1.0 mg scopolamine, young subjects also scored double correct responses in only 19% of trials, a highly significant reduction from their undrugged performance (p less than 0.01), but virtually the same as that of normal aged subjects. Similar findings were obtained with a staggered dichotic presentation. These results extend the observation that cholinergic blockade in young subjects reproduces the pattern of M/C decline of the aged; thus providing further for the hypothesis that this decline may result from impaired function in cholinergic neurons. The neurobiologic implications of cholinergic impairment are discussed.
胆碱能神经功能受损被认为是老年人记忆和认知障碍的一个原因，因为使用胆碱能阻滞剂时，年轻受试者会表现出老年人的记忆和认知模式。为了验证这一假设，我们使用一种不同类型的行为任务——双耳分听测试（主要测量神经通道容量），比较了年轻正常受试者、接受东莨菪碱治疗的年轻受试者和老年受试者的表现。在同时进行双耳呈现时，未用药的年轻受试者在35%的试验中能正确报告两条信息。老年受试者在仅19%的试验中获得双正确反应，差异极为显著（p<0.001）。在用1.0毫克东莨菪碱治疗后，年轻受试者在仅19%的试验中也获得双正确反应，与未用药时的表现相比有极显著下降（p<0.01），但实际上与正常老年受试者相同。采用交错双耳呈现时也得到了类似的结果。这些结果扩展了以下观察结果：年轻受试者中的胆碱能阻滞再现了老年人记忆和认知能力下降的模式；从而进一步支持了这一下降可能是由于胆碱能神经元功能受损的假设。文中还讨论了胆碱能损伤的神经生物学意义。
