TEMPORAL PRECISION AND DYNAMICAL CODING IN THE OLFACTORY BULB

嗅球中的时间精度和动态编码

基本信息

批准号：
8277368
负责人：
Richard C Gerkin
金额：
$ 5.57万
依托单位：
CARNEGIE-MELLON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2013-06-30
项目状态：
已结题

项目摘要

Identification of the stimulus features represented by neuronal activity, and understanding the fidelity of this representation, are central to understanding how the brain processes the sensory world. In the mammalian olfactory bulb, mitral/tufted (M/T) cells both receive synaptic input from sensory neurons, and serve as the principal output to central brain structures. Due to physical constraints, odor intensity (concentration) at odorant receptors in vertebrates is likely to vary much more slowly than stimulus intensity in other sensory modalities such as vision or audition. Because of this speed limit, the precise timing of action potentials (APs) will not track rapid, millisecond-timescale changes in stimulus properties as in other sensory systems. Rather, the extra "bandwidth" afforded by precise AP timing could encode other olfactory stimulus features, such as identity or context. If odor identity is encoded in AP timing early during a stimulus response, and this timing is reliable across identical stimuli, behavioral response latencies could be minimized11. Across respiratory cycles, an identical ensemble AP response could serve to confirm odor identity. Alternatively, directed changes in this response across cycles could convey novel information in each respiratory cycle about a complex stimulus. Here I propose to test the hypotheses that ensemble AP timing encodes features of odor stimuli in the mouse olfactory bulb, and does so in a dynamic fashion across respiratory cycles.

识别由神经元活性代表的刺激特征，以及理解这种表示的忠诚，对于理解大脑如何处理感觉世界至关重要。在哺乳动物嗅球中，二尖瓣/簇（M/T）细胞都从感觉神经元接收突触输入，并作为中央大脑结构的主要输出。由于物理限制，脊椎动物的气味受体的气味强度（浓度）的变化可能比其他感觉方式（例如视觉或试听）中的刺激强度慢得多。由于具有此速度限制，如其他感觉系统，动作电位的精确时机（AP）不会跟踪刺激性能的快速，毫秒的变化。相反，精确的AP时机提供的额外“带宽”可以编码其他嗅觉刺激特征，例如身份或上下文。如果在刺激响应期间早期对AP时机编码气味身份，并且在相同的刺激中，此时机是可靠的，则行为反应潜伏期可以最小化。11。在整个呼吸周期中，相同的集合AP响应可以用来确认气味身份。另外，在跨周期中，这种反应的定向变化可以在每个呼吸周期中传达有关复杂刺激的新信息。在这里，我建议测试集成AP时正时的假设编码小鼠嗅球中气味刺激的特征，并以跨呼吸周期的动态方式进行。