Disterhoft John F, Oh M Matthew
Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611-3008, USA.
Aging Cell. 2007 Jun;6(3):327-36. doi: 10.1111/j.1474-9726.2007.00297.x.
Normal aging subjects, including humans, have difficulty learning hippocampus-dependent tasks. For example, at least 50% of normal aging rabbits and rats fail to meet a learning criterion in trace eyeblink conditioning. Many factors may contribute to this age-related learning impairment. An important cause is the reduced intrinsic excitability observed in hippocampal pyramidal neurons from normal aging subjects, as reflected by an enlarged postburst afterhyperpolarization (AHP) and an increased spike-frequency adaptation (accommodation). In this review, we will focus on the alterations in the AHP and accommodation during learning and normal aging. We propose that age-related increases in the postburst AHP and accommodation in hippocampal pyramidal neurons play an integral role in the learning impairment observed in normal aging subjects.
包括人类在内的正常衰老个体在学习依赖海马体的任务时存在困难。例如，至少50%的正常衰老兔子和大鼠在痕迹眨眼条件反射中未能达到学习标准。许多因素可能导致这种与年龄相关的学习障碍。一个重要原因是在正常衰老个体的海马体锥体神经元中观察到的内在兴奋性降低，这表现为爆发后超极化（AHP）增大和动作电位频率适应性（适应性）增加。在本综述中，我们将重点关注学习和正常衰老过程中AHP和适应性的变化。我们提出，海马体锥体神经元中与年龄相关的爆发后AHP和适应性增加在正常衰老个体中观察到的学习障碍中起着不可或缺的作用。
