Landfield P W, Lynch G
J Gerontol. 1977 Sep;32(5):523-33. doi: 10.1093/geronj/32.5.523.
Neurophysiological experiments were conducted in vitro on 400 mu thick transverse hippocampal slices from aged and young rats. These slices exhibit neurophysiological responses similar to those of intact hippocampus. The aged rats have previously been found to exhibit impaired retention. Synaptic responses of the Schaffer collateral system were not found to be different between aged and young slices when elicited by very low frequency (0.3 Hz) electrical stimulation. However, the aged slices exhibited marked deficits in frequency and posttetanic potentiation in response to repetitive stimulation (15 Hz). This deficit was interpreted as resulting from an increased tendency to synaptic depression, rather than from impaired potentiation processes. The possibility of a relationship of these physiological deficits in hippocampal synaptic plasticity to the deficits in behavioral plasticity found in these aged animals is considered.
对老年大鼠和年轻大鼠400微米厚的海马横切片进行了体外神经生理学实验。这些切片表现出与完整海马体相似的神经生理反应。此前已发现老年大鼠存在记忆保持受损的情况。当通过极低频（0.3赫兹）电刺激诱发时，老年切片和年轻切片之间未发现Schaffer侧支系统的突触反应存在差异。然而，老年切片在重复刺激（15赫兹）时，频率和强直后增强表现出明显缺陷。这种缺陷被解释为是由于突触抑制倾向增加，而非增强过程受损所致。研究考虑了海马体突触可塑性的这些生理缺陷与这些老年动物行为可塑性缺陷之间存在关联的可能性。
