HUMAN AND ANIMAL EVOKED POTENTIALS

该项目提供的信息补充了#年获得的数据 人类的项目1和2，小鼠的项目2、3和4。这项建议 假设衰老对中枢神经系统加工的影响 听觉神经系统将表现为颞叶的改变 刺激的处理和在噪声中处理信号的能力。我们 提出随着年龄的增长，时间加工的退化反映了变化 在突触事件的时间进程中。具体地说，经济增长的放缓 突触事件导致潜伏期的增加，可能 听觉诱发电位的幅度下降是由于 突触后电位的离散度更大。从我们的听觉 脑干反应(ABR)数据，似乎时间处理和 同时掩蔽共享一种似乎是神经的机制 (具体地说，突触)在性质上，因此 ABR，如速率和前向掩蔽范例，可能强调同样的 被同侧强调的潜在过程--直接掩蔽 范例。我们将调查衰老对听力正常的年轻人的影响 以及使用ABR作为反应测量的老年人。我们会 同样地，测试青年和中年C57小鼠，以及青年小鼠， 中老年CBA小鼠。应对措施将包括 下丘记录ABR和近场电位。vbl.使用 强调突触机制的刺激范式(例如，速率、向前- 掩蔽和同时掩蔽范例)和使用因变量 对外周听力损失不敏感但对中枢敏感的人 听觉神经系统改变(例如，人类ABR中的I-V间期)， 那么应该有可能分离出这些对 罐头的老化。

This project provides information that complements the data obtained in Projects 1 and 2 in humans and Projects 2, 3 and 4 in mice. This proposal hypothesize that the effects of aging on the processing of the central auditory nervous system will be manifested as changes in the temporal processing of stimuli and in the ability to process signals in noise. We propose that degradations in temporal processing with age reflect changes in the time course of synaptic events. Specifically, the slowing of synaptic events leads to the increases in the latencies and perhaps decreases in the amplitudes of the auditory evoked potentials due to a greater dispersion of post-synaptic potentials. From our auditory brainstem responses (ABR) data, it appears that temporal processing and simultaneous masking share a mechanism that appears to be neural (specifically, synaptic) in nature, and hence temporal dependencies of the ABR, such as rate and forward masking paradigms, may stress the same underlying processes that are stressed by an ipsilateral-direct masking paradigm. We will investigate the effects of aging in normal hearing young and old human adults using the ABR as the response measure. We will similarly test young-adult and middle-aged C57 mice, and young-adult, middle-aged and old CBA mice. The response measures will include both the ABR and near-field potentials recorded from the inferior colliculus. Using stimulus paradigms that stress synaptic mechanisms (e.g., rate, forward- masking and simultaneous-masking paradigms) and using dependent variables that are insensitive to peripheral hearing loss but sensitive to central auditory nervous system changes (e.g., the I-V interval in the human ABR), then it should be possible to isolate these measures that are sensitive to aging of the CANS.