Linden Jennifer F, Liu Robert C, Sahani Maneesh, Schreiner Christoph E, Merzenich Michael M
Keck Center for Integrative Neuroscience, University of California, San Francisco, California 94143, USA.
J Neurophysiol. 2003 Oct;90(4):2660-75. doi: 10.1152/jn.00751.2002. Epub 2003 Jun 18.
The mouse is a promising model system for auditory cortex research because of the powerful genetic tools available for manipulating its neural circuitry. Previous studies have identified two tonotopic auditory areas in the mouse-primary auditory cortex (AI) and anterior auditory field (AAF)- but auditory receptive fields in these areas have not yet been described. To establish a foundation for investigating auditory cortical circuitry and plasticity in the mouse, we characterized receptive-field structure in AI and AAF of anesthetized mice using spectrally complex and temporally dynamic stimuli as well as simple tonal stimuli. Spectrotemporal receptive fields (STRFs) were derived from extracellularly recorded responses to complex stimuli, and frequency-intensity tuning curves were constructed from responses to simple tonal stimuli. Both analyses revealed temporal differences between AI and AAF responses: peak latencies and receptive-field durations for STRFs and first-spike latencies for responses to tone bursts were significantly longer in AI than in AAF. Spectral properties of AI and AAF receptive fields were more similar, although STRF bandwidths were slightly broader in AI than in AAF. Finally, in both AI and AAF, a substantial minority of STRFs were spectrotemporally inseparable. The spectrotemporal interaction typically appeared in the form of clearly disjoint excitatory and inhibitory subfields or an obvious spectrotemporal slant in the STRF. These data provide the first detailed description of auditory receptive fields in the mouse and suggest that although neurons in areas AI and AAF share many response characteristics, area AAF may be specialized for faster temporal processing.
由于有强大的基因工具可用于操纵小鼠的神经回路，小鼠是听觉皮层研究中一个很有前景的模型系统。先前的研究已经在小鼠初级听觉皮层（AI）和前听觉场（AAF）中确定了两个音调定位听觉区域——但这些区域的听觉感受野尚未被描述。为了为研究小鼠听觉皮层回路和可塑性奠定基础，我们使用频谱复杂和时间动态的刺激以及简单的音调刺激，对麻醉小鼠的AI和AAF中的感受野结构进行了表征。从细胞外记录的对复杂刺激的反应中得出频谱时间感受野（STRF），并根据对简单音调刺激的反应构建频率-强度调谐曲线。这两种分析都揭示了AI和AAF反应之间的时间差异：STRF的峰值潜伏期和感受野持续时间以及对短音突发反应的首次放电潜伏期在AI中比在AAF中显著更长。AI和AAF感受野的频谱特性更相似，尽管AI中的STRF带宽比AAF中的略宽。最后，在AI和AAF中，相当一部分STRF在频谱时间上是不可分割的。频谱时间相互作用通常以明显不相交的兴奋和抑制子场的形式出现，或者在STRF中出现明显的频谱时间倾斜。这些数据首次详细描述了小鼠的听觉感受野，并表明尽管AI和AAF区域的神经元具有许多共同的反应特征，但AAF区域可能专门用于更快的时间处理。
