School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287, USA.
Eur J Neurosci. 2013 Jan;37(1):63-79. doi: 10.1111/ejn.12021. Epub 2012 Nov 21.
Experience-related plasticity is an essential component of networks involved in early olfactory processing. However, the mechanisms and functions of plasticity in these neural networks are not well understood. We studied nonassociative plasticity by evaluating responses to two pure odors (A and X) and their binary mixture using calcium imaging of odor-elicited activity in output neurons of the honey bee antennal lobe. Unreinforced exposure to A or X produced no change in the neural response elicited by the pure odors. However, exposure to one odor (e.g. A) caused the response to the mixture to become more similar to that of the other component (X). We also show in behavioral analyses that unreinforced exposure to A caused the mixture to become perceptually more similar to X. These results suggest that nonassociative plasticity modifies neural networks in such a way that it affects local competitive interactions among mixture components. We used a computational model to evaluate the most likely targets for modification. Hebbian modification of synapses from inhibitory local interneurons to projection neurons most reliably produced the observed shift in response to the mixture. These results are consistent with a model in which the antennal lobe acts to filter olfactory information according to its relevance for performing a particular task.
经验相关的可塑性是早期嗅觉处理中涉及的网络的重要组成部分。然而，这些神经网络中可塑性的机制和功能还不是很清楚。我们通过钙成像技术评估了对两种纯气味（A 和 X）及其混合物的反应，研究了非联想性可塑性，该技术可以测量蜜蜂触角叶中输出神经元对气味诱发活动的反应。未受强化的 A 或 X 暴露对纯气味引起的神经反应没有变化。然而，暴露于一种气味（例如 A）会使混合物的反应变得更类似于另一种成分（X）。我们还在行为分析中表明，未受强化的 A 暴露会使混合物在感知上更类似于 X。这些结果表明，非联想性可塑性以影响混合物成分之间局部竞争相互作用的方式修饰神经网络。我们使用计算模型来评估最有可能的修饰目标。来自抑制性局部中间神经元到投射神经元的突触的赫布式修饰最可靠地产生了对混合物反应的观察到的转变。这些结果与一个模型一致，即触角叶根据其对执行特定任务的相关性来过滤嗅觉信息。
