HUMAN AND ANIMAL EVOKED POTENTIALS

该项目提供的信息补充了 项目1和2用于人类，项目2、3和4用于小鼠。这项建议 假设衰老对中枢神经系统的影响 听觉神经系统将表现为颞叶的变化， 处理刺激和处理噪声中的信号的能力。我们 我认为，随着年龄的增长，时间处理的退化反映了 在突触事件的时间进程中。具体来说， 突触活动导致乳酸的增加， 由于听觉诱发电位的振幅下降， 突触后电位的更大分散。从我们的听觉 脑干反应（ABR）数据，似乎时间处理和 同时掩蔽有一个共同机制， （特别是，突触）的性质，因此时间的依赖性， ABR，如速率和前掩蔽范式，可能强调相同的 受到同侧直接掩蔽的潜在过程 范例我们将调查年龄对听力正常的年轻人的影响。 和老年人使用ABR作为响应措施。我们将 类似地测试了成年和中年C57小鼠，以及成年和中年C57小鼠， 中老年CBA小鼠。应对措施将包括 从下丘记录ABR和近场电位。使用 强调突触机制的刺激范例（例如，远期汇率 掩蔽和错误掩蔽范例）和使用因变量 对周围性听力损失不敏感，但对中枢性听力损失敏感， 听觉神经系统改变（例如，人ABR中的I-V间期）， 那么应该可以分离出这些对 罐的老化。

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.