NEURAL ASSEMBLIES--PLASTICITY IN AUDITORY CORTEX

神经组装——听觉皮层的可塑性

基本信息

批准号：
6624805
负责人：
GEORGE L GERSTEIN
金额：
$ 16.97万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-09-01 至 2003-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6624805
关键词：
auditory cortex auditory discrimination auditory stimulus behavior test behavioral /social science research tag laboratory rat learning neural information processing neural plasticity neuroanatomy psychoacoustics sound frequency sound perception

项目摘要

We will continue our studies of plasticity in the auditory system using both experimental and theoretical methods. Experiments will examine the behavioral and electrophysiological consequences of several manipulations of organization rat auditory cortex. One series of experiments will use entirely physiological stimuli, and will force switches of attention between a pitch pattern and an intensity pattern in a discrimination task. A second series of experiments will directly manipulate cortex with the use of very weak electrical intra-cortical microstimulation (ICMS) in several different paradigms to modify the cortical sensory (auditory) map. Such electrical stimuli are far below direct behavioral/perceptual thresholds, but have been shown both in our and other labs to rapidly make changes in the relative size of cortical map domains (i.e. increase the number of neurons available for an appropriate task) and simultaneously to change the strength of the lateral connections between neurons in the cortical sheet. An ICMS period of minutes to several hours has effects on the cortex that last at least several hours,b ut then dissipate. For these experiments, the several stimulation paradigms will use either pure ICMS, or will combine ICMS with physiological stimuli (tone bursts), producing changes in the cortical network that are superficially similar in term of domain and receptive field changes, but which form a graded series of associations with "meaning." The effects of the cortical manipulations will be measured by performance of an appropriate pattern description task (pitch or pitch/intensity). The underlying cortical neuronal network will be studied by simultaneous separable recording of 30-50 neurons using stereotrode and tetrode technology Analysis of these data in terms of neuronal assembly properties and organization will use methods largely developed in our lab including the Joint PST histogram and the Gravity representation which delineate dynamic aspects of assembly interactions. Computer simulations will be used to mimic the observed experimental results and thus test likelihood of parameter values and mechanisms.

我们将使用实验和理论方法继续对听觉系统中的可塑性进行研究。实验将检查组织大鼠听觉皮层的几种操纵的行为和电生理后果。一系列的实验将完全使用生理刺激，并将在歧视任务中迫使音高模式和强度模式之间的注意力转换。第二系列实验将通过在几个不同范式中使用非常弱的皮层内微刺激（ICM）直接操纵皮层，以修改皮质感觉（听觉）图。这种电刺激远低于直接的行为/感知阈值，但在我们和其他实验室中都显示出可以快速改变皮质地图域的相对大小（即增加适当任务的神经元的数量），并同时改变皮质纸中神经元之间横向连接的强度。 ICMS的时间为几分钟到几个小时会对持续至少几个小时的皮层产生影响，然后消散。对于这些实验，几种刺激范式将使用纯ICM，或者将ICM与生理刺激（音调爆发）结合在一起，在域和接受场的术语和接受场变化上产生皮质网络的变化，但形成了一系列具有“含义”的分级系列。皮质操作的影响将通过执行适当的模式说明任务（音高或音高/强度）的执行来衡量。潜在的皮质神经元网络将通过使用立体原理和Tetrode技术分析这些数据对30-50个神经元进行分离进行研究，以神经元组装属性和组织对我们的实验室中有很大程度上开发的方法来研究这些数据，包括在我们的实验室直方图中开发的方法，包括联合PST形式和重力表达，其中包括重力表达，哪些划分了组装动态方面的组装方面。计算机模拟将用于模仿观察到的实验结果，从而测试参数值和机制的可能性。