AUDITORY ANATOMY IN AGING RATS WITH EXTENDED LIFESPANS

寿命延长的老龄大鼠的听觉解剖学

• 批准号: 3117131
• 负责人: MARTIN L FELDMAN
• 金额: $ 12.24万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-08-01 至 1992-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3117131
• 关键词: auditory cortex; auditory pathways; brain stem; cardiovascular system; cochlea; ear disorder; ear hair cell; electron microscopy; evoked potentials; histopathology; laboratory rat; longevity; microscopy; neuroanatomy; neurophysiology; silver impregnation; synapses

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.

拟议研究解决的主要问题是 听觉的节奏和严重程度是否存在问题 寿命缩短的动物的细胞变化发生了改变 延长超出常规限制。 拟议的研究将实现寿命的延长 通过长期限制食物，使用不 其本身不会导致虚弱或缺陷。 工作 采用解剖学和功能技术，与 观察器官和全身病理学，检查大鼠 其寿命远远超出正常限度。 这 这项工作的基本原理涉及（1）价值评估 从神经保存的角度延长寿命， （二）建立重要的老龄化新模式 研究。 要检查的具体系统是听觉系统， 在人类中表现出显着且可靠的功能的系统 以及随着年龄的增长而发生的结构退化。 观察结果 将重点关注听觉通路的两端，即耳蜗 和听觉皮层。 使用光学和电子显微镜，年龄 相关变化将在感觉毛细胞中进行分析， 突触、螺旋神经节细胞、血管纹和血管 的皮质。 皮质分析将包括使用高尔基体 允许超微结构检查的脱浸渍技术 特定识别的皮质细胞类型。 结果将是 与脑干听觉诱发结果密切相关 回应，以及根据分析解释的结果 器官系统病理学。 需要检验的主要假设如下：（1） 寿命的绝对长度是一个重要变量 与年龄相关的细胞变化的程度； （二）限制变更 大鼠以正常节奏发生，但比广告中的情况更严重 库。喂老鼠。