眼睛的快速跳动(扫视)引起多种瞬态的感知变化,它们可能是伴随放电造成的后果。本文揭示的扫视伴随放电神经回路,能对家鸽整个视觉系统的活动进行调节。扫视伴随放电致使端脑上皮质、视觉丘脑和顶盖前扁豆核(nLM)的放电活动先受抑制后被增强,但副视觉系统基底视束核(nBOR)的反应则与其相反,即先被增强后受抑制,这使丘脑神经元失活导致端脑神经元的扫视反应消失,而nLM和nBOR两者同时失活则消除丘脑神经元的扫视反应。脑干中缝核复合体与扫视有关的全向暂停神经元抑制nBOR并兴奋nLM,其失活导致视动神经元和丘脑神经元的扫视反应消失。研究表明,端脑神经元的扫视反应由伴随放电信号产生.这些信号从脑干神经元经由视动神经元和丘脑神经元传递到端脑,可能在视觉感知中起重要作用。
A saccadic eye movement causes a variety of transient perceptual sequelae that might be the results of corollary discharge. Here we described the neural circuits for saccadic corollary discharge that modulated activity throughout the pigeon visual system. Saccades m pigeons caused inhibition that was mediated by corollary discharge followed by enhancement of firing activity in the teleneephalic hyperpallium, visual thalamus and pretectal nucleus lentiformis meseneephali (nLM) with opposite responses in the accessory optic nucleus (nBOR). Inactivation of thalamic neurons eliminated saccadic responses in telencephalic neurons, and inactiration of both the nLM and the nBOR abolished saccadic responses in thalamic neurons. Saccade-related omnipause neurons in the brainstem raphe complex inhibited the nBOR and excited the nLM, whereas inactivation of raphe neurons eliminated saccadic responses in both optokinetic and thalamic neurons. It seemed that saccadic responses in telencephalic neurons were generated by corollary discharge signals from brainstem neurons that were transmitted through optokinetic and thalamic neurons. These signals might have important roles in visual pereeption.