Abrahams V C, Rose P K
J Neurophysiol. 1975 Jan;38(1):10-8. doi: 10.1152/jn.1975.38.1.10.
Unit recordings were made in the superior colliculus of cats anesthetized with chloralose and with Pentothal. Electrical stimulation of extraocular muscle afferents and neck muscle afferents excited more units in the superior colliculus than did a variety of moving and stationary visual stimuli. Units responding to neck muscle afferent stimulation fell into three populations; one population firing with a short latency and following stimulus presentation up to 1/s, a second population with a long latency and following stimulus presentation at frequencies lower than 15/min, and a third population exhibiting paired firing. The latencies and firing patterns of the third population combined the characteristics of each of the first two patterns. It is suggested that these characteristics of unit discharges stem from the existence of two pathways from neck muscle afferents to the superior colliculus. The projection is predominantly bilateral. Units responding to neck muscle afferent stimulation are distributed throughout the superior colliculus on the basis of their latencies. Long-latency responses predominate in the superficial layers of the superior colliculus and short-latency responses, while more common in the intermediate and deep layers, predominate in the tegmentum. Extraocular muscle afferent projections to the superior colliculus constitute the single richest projection found in these experiments. While the response patterns and latencies are similar to those of the neck muscle afferents, long-latency responses are the most common and dominate in all collicular regions. Few units in the tegmentum could be excited by extraocular muscle afferents. Both extraocular muscle and neck muscle afferents show considerable convergence with one another and with retinal afferents within the superior colliculus. Cells of origin of the tectospinal tract were identified within the superior colliculus and tegmentum by antidromic excitation from the upper cervical cord. These cells were distributed predominantly within the intermediate and deep layers of the superior colliculus, and sparsely in the superficial layers and tegmentum. Almost 50% of the cells of origin of the tectospinal tract receive a convergent input from extraocular muscle and neck muscle afferents and from the retina. About 30% of the cells were inexcitable to the stimuli employed in these experiments. The significance of these projections is discussed with respect to superior collicular function in the cat and i
在使用水合氯醛和硫喷妥钠麻醉的猫的上丘进行单位记录。与各种移动和静止视觉刺激相比，眼外肌传入纤维和颈部肌肉传入纤维的电刺激在上丘中兴奋了更多的单位。对颈部肌肉传入刺激有反应的单位分为三类；一类潜伏期短，在刺激呈现后以高达1次/秒的频率持续放电，第二类潜伏期长，在刺激呈现后以低于15次/分钟的频率持续放电，第三类呈现成对放电。第三类的潜伏期和放电模式结合了前两类各自的特征。有人认为，单位放电的这些特征源于从颈部肌肉传入纤维到上丘存在两条通路。这种投射主要是双侧的。对颈部肌肉传入刺激有反应的单位根据其潜伏期分布在上丘的整个区域。长潜伏期反应在上丘的浅层占主导，而短潜伏期反应虽然在中层和深层更常见，但在被盖中占主导。眼外肌传入纤维对上丘的投射是这些实验中发现的最丰富的单一投射。虽然反应模式和潜伏期与颈部肌肉传入纤维相似，但长潜伏期反应是最常见的，并且在所有丘区域中占主导。被盖中很少有单位能被眼外肌传入纤维兴奋。眼外肌和颈部肌肉传入纤维在上丘内彼此之间以及与视网膜传入纤维都表现出相当程度的汇聚。通过来自颈上脊髓的逆向兴奋，在上丘和被盖中鉴定出顶盖脊髓束的起源细胞。这些细胞主要分布在上丘的中层和深层，在浅层和被盖中分布稀疏。几乎50%的顶盖脊髓束起源细胞接受来自眼外肌和颈部肌肉传入纤维以及视网膜的汇聚输入。约30%的细胞对这些实验中使用的刺激无反应。就猫的上丘功能讨论了这些投射的意义。
