Models of Sensory Coding

描述(申请人提供)：这项提案的目标是使用直接的实验方法来测试两种嗅觉编码模型的预测。一种模型认为许多低特异性的神经元件代表每种气味，另一种模型表明更少、更特异的嗅觉受体结合起来传达有关多种分子特征的信息，以表征每种气味。低特异性模型预测任何病变对任何气味的编码没有影响，而组合模型预测局灶性病变的特定缺陷。为了验证这些预测，我们将确定局灶性嗅球损伤对特定气味的识别、辨别和检测的影响。为此，我们的实验室一直在研究大量系统不同的气味物质引起的肾小球活动，并表征了结合形成其独特焦点表示的响应域。重要的是，我们已经确定了气味对，它们引起的肾小球模式只有一个反应区域不同。根据这些区域的位置，我们建议损毁大鼠局部肾小球活动的特定区域，然后我们建议应用行为测试来揭示它们由此产生的气味感知。这些实验应该有助于我们理解嗅觉神经系统编码复杂刺激的机制。

DESCRIPTION (provided by applicant): The goal of this proposal is to use direct experimental approaches to test the predictions of two models of olfactory coding. One model suggests that many low-specificity neural elements represent each odorant and the other model suggests that fewer, more specific olfactory receptors combine to convey information regarding multiple molecular features to characterize each odorant. The low-specificity model predicts no effect of any lesion on the coding of any odorant, while the combinatorial model predicts specific deficits with focal lesions. To test these predictions, we will determine the effects of focal olfactory bulb lesions on the recognition, discrimination, and detection of specific odorants. To that end, our laboratory has been studying the glomerular activity evoked by a large number of systematically differing odorants and we have characterized the response domains that combine to form their unique focal representations. Importantly, we have identified odorant pairs that evoke glomerular patterns differing only by a single response domain. Guided by the locations of these domains, we propose to lesion specific areas of focal glomerular activity of rats and we then propose to apply behavioral tests to reveal their resulting odor perceptions. These experiments should help us understand the mechanism by which the olfactory nervous system codes complex stimuli.