Models of Sensory Coding

描述（由申请人提供）：本提案的目标是使用直接实验方法来测试两种嗅觉编码模型的预测。一种模型表明，许多低特异性的神经元素代表每种气味，另一种模型表明，更少、更特异性的嗅觉受体结合起来传递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编码的影响，而组合模型预测局灶性病变的特异性缺陷。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由大量系统不同气味引起的肾小球活动，我们已经描述了反应域，这些反应域结合起来形成了它们独特的焦点表征。重要的是，我们已经确定了气味对，唤起肾小球模式的差异只有一个单一的反应域。根据这些区域的位置，我们建议损伤大鼠局灶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产生的气味感知。这些实验将有助于我们理解嗅觉神经系统对复杂刺激进行编码的机制。

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.