蛤蚧和鳄蜥峡核的电生理研究

本文用细胞外记录和硫化钴标记技术研究了蛤蚧(Gekko gekko)和鳄蜥(Shini-saurus crocodilurus)峡核单位的感觉反应.结果指出:(1)峡核大细胞都(Imc)是视觉中枢;(2)Imc内存在照度反应(luxotonic)单位;(3)Imc单位对运动的反差目标反应活泼,35％单位只在目标进出其感受域瞬间发放脉冲 ;(4)Imc内有双眼单位 ;(5)视野在Imc上呈区域对应投射。     

ELECTROPHYSIOLOGICAL STUDIES ON THE NUCLEUS ISTHMI OF THE LIZARDS Gekko gekko AND Shinisaurus crocodilurus

This report studies visual responses of the isthmic units in Gekko gekko and Shinisaurus crocodilurus using extracellular recording and cobalt sulfide marking techniques. Our results indicate that: (ⅰ) the nucleus isthmi pars magnocellularis (Imc) is a visual center; (ⅱ) there are luxotonic units in Imc; (ⅲ) Imc units respond vigorously to moving contrast targets, of which 35% units burst only at the moment when targets are moving into and out of their receptive fields, none react to either tactile or auditory stimulation; (ⅳ) there exist binocular units in Imc; and (ⅴ) visual field is topographically projected onto Imc.     

NUCLEUS ISTHMUS OF TOAD IS SECONDARY VISUAL CENTER

Visual responses of 148 units have been recorded with micropipettes from the left nucleusisthmus areas of toads (Bufo bufo gargarizans), their auditory and tactile responses also exa-mined, and 122 recording sites marked with cobalt sulphide. This study indicates that: (i) 118units responding solely to visual stimuli are found within the nucleus, and 4 multisensory unitsoutside, (ii) there exist a visual field map and binocular units in the nucleus, and (iii) res-ponse latencies of the isthmic units to a spot of light range from 120 to 540 msee, with nocorrelation with recording sites.     

蟾蜍的峡核是次级视觉中枢

从中华大蟾蜍(Bufo bufo gargarixans)峡核区域记录了148个视觉单位,检验了它们对声和触刺激的反应,并用硫化钴标记出其中122个记录位置。结果指出:(1)118个只对视刺激有反应的单位在峡核内,4个多感觉单位在核外;(2)峡核内有个视野对应投射图和双眼单位;和(3)峡核单位对光点的反应潜伏期为120—540毫秒,和记录位置无关。     

蛙峡核的视野区域对应投射和双眼反应

本文用玻璃微电极从黑斑蛙(Rana nigromaculata)左峡核细胞外记录了125个单位的视觉反应,并用钴染色法标记出101个电极尖端位置,以便重建峡核内的视野图。在所记录的单位中,80％对静止光点显示给光(ON)-撤光(OFF)反应,许多单位对通过其感受域的黑、白目标的运动有方向选择性。所有钴标记点都在核内,表明峡核本身是蛙视觉系统的一个局限部分。在峡核内有一个视野投射圈。整个对侧半视野和同侧半视野的鼻侧40°呈区域对应地投射到峡核上。核内的无细胞带是对侧半视野与同侧半视野的分界线,它的背侧是对侧视野代表区。上视野投射到核的嘴半部、尾半部的中央和内腹部分。下视野的代表在尾半部的背部和外侧部。在峡核里观察到15个双眼单位,其中13个主要被对侧眼兴奋,2个几乎同等地被两只单眼兴奋。标记成功的14个双眼单位主要位于峡核嘴半部的髓质内。