Functions of ascending, descending and recurrent inputs to the lateral geniculate nucleus of thalamus

为了阐明外侧膝状体（LGN）感受野（RF）特性的机制，我们研究了麻醉和麻痹猫视网膜神经节细胞（RGCs）、LGN和视皮层神经元的RF特性以及它们之间的功能相互作用。RGC和LGN神经元的经典感受野（CRF）呈椭圆形，具有抑制性超经典感受野环绕（ECRF），对刺激方向和空间频率产生调谐特性。这些结果表明，在早期视觉系统中，前馈机制使ECRF的基本调谐特性，反馈机制通过非线性操作增强调谐特性

To clarify the mechanisms underlying the receptive field(RF) properties of the lateral geniculte nucleus(LGN), we examined the RF properties of retinal ganglion cells(RGCs), neurons in the LGN and visual cortex, and functional interactions among them in the anesthetized and paralyzed cats. The classical receptive field(CRF) of RGC and LGN neurons are elliptical in shape with suppressive extra-classical RE surround(ECRF), which produce tuning properties to the stimulus orientation and spatial frequency. These results suggest that, in the early visual system, the feedforward mechanism makes the basic tuning properties, and the feedback mechanisms enhance the tuning properties via non-linear operation of ECRF