EFFECTS OF LEAD ON AUDITORY SYSTEM IN MONKEYS: HEARING

目的：检测老年人的听觉系统功能和注意力， 恒河猴作为儿童期铅暴露的模型。 外围 和高阶听觉过程使用行为和 电生理技术。 结果我们开发了一种新的 行为测试，以评估先前铅暴露对 注意，我们继续在这项任务中测试动物。 我们的研究 和其他人的研究已经证明了早期铅暴露对 儿童和动物模型的听觉过程。 我们评估 这些影响发生在听觉系统的多个层次上， 通过行为和电生理技术。 具体 对听觉系统的影响可能有助于更全球性的 与儿童期铅暴露相关的认知异常。 这些包括智商下降（特别是语言智商），注意力缺陷， 言语知觉受损，语言表现受损 生产任务、阅读障碍和学校问题。 更好的 了解听觉系统对不良 早期铅暴露的后果将有助于设计 儿童治疗干预和特殊教育方案 以及已知经历过早期铅暴露的成年人。 广泛 一系列的行为和生理研究将检查听觉 多层次的系统完整性。 行为测试将测量 绝对和差值阈值、频率选择性，以及 时间上的区别，在很宽的频率范围内。 这些任务也评估某些注意过程和功能 基本的言语和语言处理。 生理学评价 将提供关于这些基本听觉过程的信息。 此外，躯体感觉系统的电生理学研究 将评估早期铅暴露对这一重要途径的影响 并确定铅诱导的听觉系统的特异性 之前在相同的猴子中观察到的异常。 我们还将 检查药理学干预和程序的有效性 减少铅对儿童行为和生理影响的变化 听觉处理 拟议研究的受试者为17名成人 (15岁）的猴子在早期发育过程中暴露于铅。 我们的目标 最终评估持久的和可能不可逆转的影响， 早期铅暴露 阐明铅的影响 曝光注意。 关键词铅，猴子，听力， 电生理学，认知，听觉加工

OBJECTIVE: To examine auditory system function and attention in the rhesus monkey as a model of childhood lead exposure. Peripheral and higher order auditory processes are evaluated using behavioral and electrophysiological techniques. RESULTS We developed a new behavioral test to assess the effects of previous lead exposure on attention and we continue to test animals in this task. Our studies and others' have demonstrated the effects of early lead exposure on auditory processes in children and in animal models. We evaluated these effects, which occur at multiple levels of the audi-tory system, through behavioral and electrophysiologic techniques. Specific effects on the auditory system likely contribute to the more global cognitive abnormalities associated with childhood lead exposure. These include reduced IQ (especially verbal IQ), attentional deficits, impaired speech per-ception, impaired performance on language production tasks, reading disabilities and school prob-lems. A better understanding of auditory system contributions to the adverse consequences of early lead exposure would facilitate the design of therapeutic interventions and special education programs for children and adults known to have experienced early lead exposure. A broad range of behavioral and physiologic studies will examine auditory system integrity at multiple levels. Behavioral tests will measure absolute and difference thresholds, frequency selectivity, and temporal discriminations, all over a broad range of frequencies. These tasks also evaluate certain attentional processes and func-tions underlying speech and language processing. Physiologic evaluations will provide information on these same fundamental auditory processes. In addition, electrophysiologic studies of the somato-sensory system will evaluate effects of early lead exposure on this important pathway and determine the specificity to the auditory system of lead-induced abnormalities observed previously in the same monkeys. We will also examine the efficacy of phar-macological interventions and procedural changes to attenuate behavioral and physiological effects of lead on auditory processing. Subjects for the proposed studies are 17 adult (15 yr-old) monkeys exposed to lead during early development. We aim to ultimately evaluate enduring and possibly irre-versible effects of early lead exposure. FUTURE DIRECTIONS To clarify effects of lead exposure on attention. KEY WORDS lead, monkeys, hearing, electrophysiological, cognition, auditory processing