Linster Christiane, Menon Alka V, Singh Christopher Y, Wilson Donald A
Computational Physiology Laboratory, Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA.
Learn Mem. 2009 Jun 24;16(7):452-9. doi: 10.1101/lm.1403509. Print 2009 Jul.
Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system and is thought to be behaviorally mediated by olfactory habituation memory. Data from our laboratory have shown that odor-specific adaptation in piriform neurons, mediated at least partially by synaptic adaptation between the olfactory bulb outputs and piriform cortex pyramidal cells, is highly odor specific, while that observed at the synaptic level is specific only to certain odor features. Behavioral data show that odor habituation memory at short time constants corresponding to synaptic adaptation is also highly odor specific and is blocked by the same pharmacological agents as synaptic adaptation. Using previously developed computational models of the olfactory system we show here how synaptic adaptation and potentiation interact to create the observed specificity of response adaptation. The model analyzes the mechanisms underlying the odor specificity of habituation, the dependence on functioning cholinergic modulation, and makes predictions about connectivity to and within the piriform neural network. Predictions made by the model for the role of cholinergic modulation are supported by behavioral results.
从背景气味中分离出目标气味是嗅觉系统的一项基本计算要求，并且被认为是由嗅觉习惯化记忆介导的行为。我们实验室的数据表明，梨状神经元中的气味特异性适应，至少部分是由嗅球输出与梨状皮质锥体细胞之间的突触适应介导的，具有高度的气味特异性，而在突触水平观察到的适应仅对某些气味特征具有特异性。行为数据表明，与突触适应相对应的短时间常数下的气味习惯化记忆也具有高度的气味特异性，并且被与突触适应相同的药理试剂所阻断。利用先前开发的嗅觉系统计算模型，我们在此展示了突触适应和增强如何相互作用以产生观察到的反应适应特异性。该模型分析了习惯化气味特异性的潜在机制、对胆碱能调制功能的依赖性，并对与梨状神经网络的连接以及梨状神经网络内部的连接进行了预测。该模型对胆碱能调制作用的预测得到了行为结果的支持。
