AUDITORY ANATOMY IN AGING RATS WITH EXTENDED LIFESPANS

拟议研究所解决的主要问题是 是否节奏和听觉的严重性的问题， 细胞变化在动物中发生改变， 超越常规极限。 这项研究提出将实现这种延长寿命 通过长期的食物限制，使用一种 本身并不导致虚弱或不足。 工作 采用解剖和功能技术， 器官和全身病理学观察，以检查大鼠 他们的寿命大大超过了正常的极限。 的 基本原理的工作涉及（1）评估的价值 从神经保护的角度来看， （2）建立了一个重要的老龄化新模型 research. 要检查的具体系统是听觉系统， 在人类中，表现出显著和可靠功能的系统 和结构退化。 的意见 将集中在听觉通路的两端，耳蜗 和听觉皮层。 使用光学和电子显微镜，年龄- 将在感觉毛细胞中分析相关变化， 突触、螺旋神经节细胞、血管纹和血管 大脑皮层 皮层分析将包括高尔基体的使用 脱浸渍技术，以便进行超微结构检查 特定的皮质细胞类型。 结果将 与脑干听觉诱发电位结果密切相关 答复，并根据对下列问题的分析解释调查结果： 器官系统病理学 其中主要的假设要测试如下：（1） 寿命的绝对长度是一个重要的变量， 与年龄相关的细胞变化的程度;（2）限制性 大鼠以正常节奏发生，但比AD更严重 lib.喂老鼠

The major issue addressed by the proposed research is the question of whether the tempo and the severity of auditory cellular changes are altered in animals whose lifespans are prolonged beyond conventional limits. The research proposed will achieve this prolongation of lifespan by means of chronic food restriction, using a regimen that does not in and of itself lead to debility or deficiency. The work employs anatomical and functional techniques, correlated with observations of organ and systemic pathology, to examine rats whose lifespans are extended well beyond normal limits. The rationale underlying the work involves (1) assessment of the value of lifespan extension from the standpoint of neural preservation, and (2) establishment of an important new model for aging research. The specific system to be examined is the auditory system, a system which, in humans, exhibits marked and reliable functional and structural degradation with advancing age. The observations will focus on the two ends of the auditory pathway, the cochlea and auditory cortex. Using light and electron microscopy, age- related changes will be analyzed in the sensory hair cells, synapses, spiral ganglion cells, stria vascularis, and blood vessels of the cortex. The cortical analysis will include the use of Golgi deimpregnation techniques to permit ultrastructural examination of specifically identified cortical cell types. The results will be closely correlated with the results of brainstem auditory evoked responses, and the findings interpreted in the light of analyses of organ system pathology. Among the major hypotheses to be tested are the following: (1) the absolute length of the lifespan is a significant variable in extent of age-related cellular change; (2) changes in restricted rats occur at normal tempo, but are more severe than those in ad lib. fed rats.