出生后大鼠听皮层神经元对新异声刺激频率的探测能力的发育

发布时间：2018-03-26 18:37

本文选题：刺激特异性适应　切入点：听皮层　出处：《华东师范大学》2017年硕士论文

【摘要】：在自然环境中,人类和动物需要感知环境中的各种变化并对此及时作出相应反应。对动物而言,对周围环境中的新异刺激或事件及时作出反应是一种对生存至关重要的能力。刺激特异性适应(stimulus-specific adaptation,SSA)是指感觉中枢中某些神经元对新异刺激(小概率刺激)的反应强于对标准刺激(大概率刺激)的反应的现象。尽管已在多种成年哺乳动物以及鸟类的听觉中枢上对SSA进行了深入的研究,然而,到目前为止,幼年动物的听觉中枢中是否存在SSA现象,以及SSA的程度如何还不清楚。本研究的主要目的是观察幼年时期的大鼠听皮层神经元是否存在SSA现象,并与成年大鼠听皮层神经元的SSA进行比较,为进一步理解大鼠出生后听觉中枢的功能发育提供实验依据。本实验是在三组不同年龄的大鼠上进行的:婴儿大鼠组(Infant,P 15-20),幼年大鼠组(Juvenile,P 21-30)和成年大鼠组(Adult,P 64-91)。用电生理学方法在三组大鼠初级听皮层记录神经元对新异声刺激序列的听反应,结果发现:在大鼠出生后的不同时期,大鼠听皮层神经元表现出不同程度的SSA,幼年时期(婴儿组和幼年组)的大鼠听皮层具对新异声刺激频率探测能力的神经元比例低于成年大鼠,幼年期大鼠听皮层神经元的刺激特异性适应指数也低于成年大鼠。此外,三组大鼠听皮层大多数神经元对新异声刺激反应的首次发放潜伏期短于对标准声刺激反应的首次发放潜伏期。本研究结果表明,大鼠初级听皮层的少数神经元在幼年时期已表现出对新异声刺激频率的探测能力,听皮层神经元对新异声刺激频率的探测能力在出生后有一个发育和完善的过程。
[Abstract]:In the natural environment, humans and animals need to perceive and respond to changes in the environment in a timely manner. The ability to respond in a timely manner to new or unusual stimuli or events in the surrounding environment is a vital ability for survival. Stimulus-specific adaptation (SSAs) refers to the response of some neurons in the sensory center to new and unusual stimuli (small probability stimuli). The phenomenon is stronger than the response to standard stimuli (large probability stimuli). Although SSA has been studied in the auditory centers of a variety of adult mammals and birds, However, it is not clear whether there is SSA in the auditory center of young animals and how far SSA is. The main purpose of this study was to observe the presence of SSA in neurons in the auditory cortex of young rats. The SSA of auditory cortex neurons in adult rats was compared with that in adult rats. In order to further understand the functional development of the postnatal auditory center in rats, the experiment was conducted on three groups of rats of different ages: infantile rat group, juvenile rat group, juvenile rat group, juvenile rat group, and adult rat group. The physiological methods recorded the auditory responses of neurons to new and abnormal stimuli in the primary auditory cortex of three groups of rats. The results showed that: at different periods after birth, Rat auditory cortical neurons showed different degrees of SSA.The proportion of neurons in the auditory cortex of young rats (infant and juvenile) with the ability to detect the frequency of new sounds was lower than that of adult rats. The stimulation-specific adaptation index of auditory cortical neurons in juvenile rats was also lower than that in adult rats. The first release latency of most neurons in the auditory cortex of the three groups was shorter than that of the standard acoustic stimuli. A few neurons in the primary auditory cortex of rats have demonstrated the ability to detect the frequency of new and abnormal sounds in their infancy, and the ability of the neurons in the auditory cortex to detect the frequencies of new and abnormal sounds has a process of development and improvement after birth.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q42

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