Barker D A, Dreher B
Department of Anatomy and Histology, Institute for Biomedical Research, The University of Sydney, New South Wales, Australia.
J Comp Neurol. 1998 Apr 6;393(2):210-30. doi: 10.1002/(sici)1096-9861(19980406)393:2<210::aid-cne6>3.0.co;2-5.
We have examined the development of parvalbumin immunoreactivity in the superior colliculi (SC) of the perinatal and mature rats and rabbits. In mature animals, parvalbumin-expressing cells (PECs) and neuropil in the retinorecipient layers were distributed in a continuous single band extending throughout the entire extent of the colliculus, whereas those in the intermediate layers formed distinct, radially oriented patches. Parvalbumin was expressed for the first time on postconceptional day 34 (PCD 34, postnatal day 12) and PCD 42 (postnatal day 11) in the SC of rat and rabbit, respectively. During ensuing development, both the thickness of the parvalbumin-expressing band in the retinorecipient layers and the numbers of PECs in this band gradually increased, reaching adultlike values by PCD 44 and PCD 50 in the rat and rabbit, respectively. In the rat, monocular eye enucleations on PCD 23 resulted in approximately 55% reduction in the number of PECs in the retinorecipient layers of the contralateral colliculi examined on PCD 44 or PCD 50. Unilateral ablations of the entire visual cortex on PCD 23 (before the first corticotectal fibers from visual cortices reach the SC) or on PCD 28 (when about half of the corticotectal fibers have reached colliculus) resulted in, respectively, approximately 55% and approximately 25% relative reduction in the number of PECs in the retinorecipient layers of the ipsilateral colliculi examined on PCD 44 or PCD 50. We conclude that the ontogenetic expression of parvalbumin in most of PECs in the retinorecipient collicular layers is induced by the activity of the contralateral retinotectal and/or the activity of the ipsilateral corticotectal afferents.
我们研究了围产期和成年大鼠及家兔上丘（SC）中小清蛋白免疫反应性的发育情况。在成年动物中，视网膜接受层中表达小清蛋白的细胞（PECs）和神经纤维网分布在一条连续的单带中，贯穿整个上丘，而中间层中的PECs和神经纤维网则形成明显的、径向排列的斑块。小清蛋白分别在大鼠和家兔上丘中于受孕后第34天（PCD 34，出生后第12天）和PCD 42（出生后第11天）首次表达。在随后的发育过程中，视网膜接受层中小清蛋白表达带的厚度以及该带中PECs的数量均逐渐增加，在大鼠和家兔中分别在PCD 44和PCD 50时达到成年水平。在大鼠中，于PCD 23进行单眼摘除，导致在PCD 44或PCD 50检查时，对侧上丘视网膜接受层中PECs的数量减少约55%。在PCD 23（在来自视皮层的第一批皮质-上丘纤维到达上丘之前）或PCD 28（当约一半的皮质-上丘纤维到达上丘时）对整个视皮层进行单侧切除，分别导致在PCD 44或PCD 50检查时，同侧上丘视网膜接受层中PECs的数量相对减少约55%和约25%。我们得出结论，视网膜接受性上丘层中大多数PECs中小清蛋白的个体发生表达是由对侧视网膜-上丘的活动和/或同侧皮质-上丘传入纤维的活动诱导的。
