Guo Wei, Clause Amanda R, Barth-Maron Asa, Polley Daniel B
Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA; Center for Computational Neuroscience and Neural Technology, Boston University, Boston, MA 02215, USA.
Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA.
Neuron. 2017 Jul 5;95(1):180-194.e5. doi: 10.1016/j.neuron.2017.05.019. Epub 2017 Jun 15.
Sensory processing must be sensitive enough to encode faint signals near the noise floor but selective enough to differentiate between similar stimuli. Here we describe a layer 6 corticothalamic (L6 CT) circuit in the mouse auditory forebrain that alternately biases sound processing toward hypersensitivity and improved behavioral sound detection or dampened excitability and enhanced sound discrimination. Optogenetic activation of L6 CT neurons could increase or decrease the gain and tuning precision in the thalamus and all layers of the cortical column, depending on the timing between L6 CT activation and sensory stimulation. The direction of neural and perceptual modulation - enhanced detection at the expense of discrimination or vice versa - arose from the interaction of L6 CT neurons and subnetworks of fast-spiking inhibitory neurons that reset the phase of low-frequency cortical rhythms. These findings suggest that L6 CT neurons contribute to the resolution of the competing demands of detection and discrimination.
感觉处理必须足够敏感，以编码接近噪声底限的微弱信号，但又要有足够的选择性，以区分相似的刺激。在这里，我们描述了小鼠听觉前脑中的一个六层皮质丘脑（L6 CT）回路，该回路交替地使声音处理偏向超敏反应，从而改善行为声音检测，或降低兴奋性并增强声音辨别能力。根据L6 CT激活与感觉刺激之间的时间关系，对L6 CT神经元进行光遗传学激活可以增加或降低丘脑和皮质柱各层的增益和调谐精度。神经和感知调制的方向——以牺牲辨别力为代价增强检测能力，反之亦然——源于L6 CT神经元与快速放电抑制性神经元子网的相互作用，这些子网会重置低频皮质节律的相位。这些发现表明，L6 CT神经元有助于解决检测和辨别这两种相互竞争需求的问题。
