Allen Institute for Brain Science Seattle, WA, USA.
Front Syst Neurosci. 2011 Jan 13;4:162. doi: 10.3389/fnsys.2010.00162. eCollection 2011.
The putative excitatory and inhibitory cell classes within the mouse primary visual cortex V1 have different functional properties as studied using recording microelectrode. Excitatory neurons show high selectivity for the orientation angle of moving gratings while the putative inhibitory neurons show poor selectivity. However, the study of selectivity of the genetically identified interneurons and their subtypes remain controversial. Here we use novel Cre-driver and reporter mice to identify genetic subpopulations in vivo for two-photon calcium dye imaging: Wfs1(+)/Gad1(-) mice that labels layer 2/3 excitatory cell population and Pvalb(+)/Gad1(+) mice that labels a genetic subpopulation of inhibitory neurons. The cells in both mice were identically labeled with a tdTomato protein, visible in vivo, using a Cre-reporter line. We found that the Wfs1(+) cells exhibited visual tuning properties comparable to the excitatory population, i.e., high selectivity and tuning to the angle, direction, and spatial frequency of oriented moving gratings. The functional tuning of Pvalb(+) neurons was consistent with previously reported narrow-spiking interneurons in microelectrode studies, exhibiting poorer selectivity than the excitatory neurons. This study demonstrates the utility of Cre-transgenic mouse technology in selective targeting of subpopulations of neurons and makes them amenable to structural, functional, and connectivity studies.
在使用记录微电极研究中，小鼠初级视觉皮层 V1 中的假定兴奋性和抑制性细胞类具有不同的功能特性。兴奋性神经元对运动光栅的方向角度表现出高选择性，而假定的抑制性神经元选择性差。然而，对遗传鉴定的中间神经元及其亚型的选择性研究仍然存在争议。在这里，我们使用新型 Cre-驱动和报告小鼠在体内识别两种钙染料成像的遗传亚群：标记层 2/3 兴奋性细胞群体的 Wfs1(+)/Gad1(-)小鼠和标记抑制性神经元遗传亚群的 Pvalb(+)/Gad1(+)小鼠。两种小鼠中的细胞均使用 Cre-报告系进行体内标记，具有相同的 tdTomato 蛋白可见。我们发现，Wfs1(+)细胞表现出与兴奋性群体相当的视觉调谐特性，即对定向运动光栅的角度、方向和空间频率具有高选择性和调谐性。Pvalb(+)神经元的功能调谐与微电极研究中先前报道的窄峰中间神经元一致，其选择性比兴奋性神经元差。这项研究证明了 Cre 转基因小鼠技术在选择性靶向神经元亚群中的有用性，并使其易于进行结构、功能和连接性研究。
