Neuroscience Program, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 0200, Australia.
Cereb Cortex. 2010 Dec;20(12):2971-84. doi: 10.1093/cercor/bhq046. Epub 2010 May 10.
The primary olfactory (or piriform) cortex is a trilaminar paleocortex that is seen increasingly as an attractive model system for the study of cortical sensory processing. Recent findings highlight the importance of γ-amino butyric acid (GABA)-releasing interneurons for the function of the piriform cortex (PC), yet little is known about the different types of interneurons in the PC. Here, we provide the first detailed functional characterization of the major classes of GABAergic interneurons in the anterior piriform cortex (aPC) and show how these classes differentially engage in phasic synaptic inhibition. By measuring the electrical properties of interneurons and combining this with information about their morphology, laminar location, and expression of molecular markers, we have identified 5 major classes in the aPC of the mouse. Each layer contains at least one class of interneuron that is tuned to fire either earlier or later in a train of stimuli resembling the input received by the PC in vivo during olfaction. This suggests that the different subtypes of interneuron are specialized for providing synaptic inhibition at different phases of the sniff cycle. Thus, our results suggest mechanisms by which classes of interneurons play specific roles in the processing performed by the PC in order to recognize odors.
初级嗅觉（或梨状）皮层是三层的古皮层，越来越被视为研究皮层感觉处理的有吸引力的模型系统。最近的发现强调了γ-氨基丁酸（GABA）释放中间神经元对梨状皮层（PC）功能的重要性，但对于 PC 中的不同类型的中间神经元知之甚少。在这里，我们首次详细描述了前梨状皮层（aPC）中主要 GABA 能中间神经元的功能特征，并展示了这些中间神经元类如何在相位性突触抑制中差异参与。通过测量中间神经元的电特性，并将其与形态学、分层位置和分子标记表达的信息相结合，我们在小鼠的 aPC 中鉴定出 5 种主要的中间神经元类。每个层至少包含一种中间神经元类，其被调谐为在类似于 PC 在体内嗅觉过程中接收的输入的刺激序列中更早或更晚地放电。这表明不同亚型的中间神经元专门用于在嗅探循环的不同阶段提供突触抑制。因此，我们的结果表明，中间神经元类在 PC 执行的识别气味的处理中发挥特定作用的机制。
