Rossner S, Kues W, Witzemann V, Schliebs R
University of Leipzig, Paul Flechsig Institute for Brain Research, Department of Neurochemistry, Germany.
Int J Dev Neurosci. 1993 Jun;11(3):369-78. doi: 10.1016/0736-5748(93)90008-2.
The postnatal development of laminar pattern of m1-, m3- and m4-mRNA-muscarinic acetylcholine receptor subtypes in the visual cortex of both normally raised and monocularly deprived rats (one eyelid sutured at the age of 11 days) was studied using in situ hybridization histochemistry and computer-assisted image analysis. From birth until day 15 the level of m1-receptor transcript in layer II/III increases markedly as compared to deeper layers. From day 15 up to day 18 a transient bimodal pattern develops with peaks in layers II/III and VI. Already on day 35 a more homogeneous distribution of m1-receptor mRNA level is detectable persisting until adulthood. In contrast, the m3-receptor mRNA shows already at birth a bimodal distribution with peaks in layers II/III and VI. Further development until adulthood results in transient changes in the ratio of the mRNA levels in these layers. In the adult visual cortex a similar laminar pattern as at birth is observed. From day 1 up to day 10 a relative increase in the mRNA level of the m4-receptor in layers II to IV is observed. From day 10 until day 15 a bimodal distribution of receptor mRNA develops with peaks in layers III and VI which is similar to the adult stage. However, between days 18 and 35 a shift in the laminar receptor mRNA distribution occurs resulting in peaks in layers IV and VI. The labeling of the m5-receptor transcript in rat visual cortex was very weak and did not show any alteration with age. Unilateral eyelid closure from postnatal day 11 resulted in transient changes in the laminar distribution of m3- and m4-receptor mRNA between postnatal days 18 and 25, whereas the development of the laminar pattern of the m1-receptor mRNA was not affected regardless of the length of visual deprivation. The distinct laminar developmental pattern of mRNA muscarinic receptor subtypes in rat visual cortex suggests specific roles of the muscarinic receptor subtypes during the first weeks of postnatal maturation of visual function.
采用原位杂交组织化学和计算机辅助图像分析技术，研究了正常饲养和单眼剥夺大鼠（11日龄时缝合一只眼睑）视皮层中m1、m3和m4型mRNA毒蕈碱型乙酰胆碱受体亚型的产后层状模式发育。从出生到第15天，与深层相比，II/III层中m1受体转录本水平显著增加。从第15天到第18天，出现短暂的双峰模式，在II/III层和VI层出现峰值。在第35天时，已可检测到m1受体mRNA水平更为均匀的分布，并持续至成年。相比之下，m3受体mRNA在出生时就呈现双峰分布，在II/III层和VI层出现峰值。直至成年的进一步发育导致这些层中mRNA水平比例的短暂变化。在成年视皮层中，观察到与出生时相似的层状模式。从第1天到第10天，观察到II至IV层中m4受体mRNA水平相对增加。从第10天到第15天，受体mRNA出现双峰分布，在III层和VI层出现峰值，这与成年阶段相似。然而，在第18天至第35天之间，层状受体mRNA分布发生偏移，导致在IV层和VI层出现峰值。大鼠视皮层中m5受体转录本的标记非常弱，且未显示出随年龄的任何变化。出生后第11天开始的单侧眼睑闭合导致出生后第18天至25天之间m3和m4受体mRNA层状分布的短暂变化，而无论视觉剥夺时间长短，m1受体mRNA层状模式的发育均未受影响。大鼠视皮层中mRNA毒蕈碱受体亚型独特的层状发育模式表明，毒蕈碱受体亚型在出生后视觉功能成熟的最初几周具有特定作用。
