Yan X X, Garey L J, Jen L S
Department of Anatomy, Charing Cross and Westminster Medical School, London, UK.
Brain Res Dev Brain Res. 1994 May 13;79(1):29-38. doi: 10.1016/0165-3806(94)90046-9.
The activity of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), an enzyme related to the synthesis of nitric oxide (NO), was studied histochemically in rat neocortex from the day of birth (P0) to young adulthood. At birth, NADPH-d containing neurons were already identifiable, sparsely distributed in the deep half of the pallium of the cerebrum. In addition, weakly stained bands of NADPH-d positive neuropil were detectable in layers VI and deep V and the cortical plate (CP). During the first postnatal week, NADPH-d positive neurons increased markedly, especially in CP and the superficial layers. By P7 the cells were mainly in layers VIb and II/III. Differential NADPH-d activity in the neuropil during this period appeared as higher activity gradually moving upwards until the highest intensity localised in layers II and upper III. In the caudal part of the cortex, the higher activity covered the whole of the supragranular layers. By the end of the second postnatal week, both the number and laminar distribution of NADPH-d neurons were adult-like, still mainly in layers VIb and II/III. The staining intensity in the neuropil was generally reduced but the banding pattern seen at P7 was still present. No detectable changes in the patterns of NADPH-d positive cells and neuropil in the neocortex occurred after the second postnatal week. The rostral part of the cortex matured slightly earlier than the caudal part. These results show that the development of NADPH-d activity correlates with the laminar differentiation and suggest that NADPH-d or NO may play an important role in the maturation of cortical neurons including the establishment of functional connections.
从出生日（P0）到成年早期，采用组织化学方法研究了烟酰胺腺嘌呤二核苷酸磷酸黄递酶（NADPH-d）的活性，该酶与一氧化氮（NO）的合成有关。出生时，含NADPH-d的神经元已可辨认，稀疏分布于大脑皮层深层。此外，在VI层、深层V层和皮质板（CP）中可检测到NADPH-d阳性神经纤维的弱染色带。在出生后的第一周，NADPH-d阳性神经元显著增加，尤其是在CP层和表层。到P7时，细胞主要位于VIb层和II/III层。在此期间，神经纤维中NADPH-d的差异活性表现为较高活性逐渐向上移动，直到最高强度位于II层和III层上部。在皮质尾部，较高活性覆盖了整个颗粒上层。到出生后第二周结束时，NADPH-d神经元的数量和分层分布已类似成年状态，仍主要在VIb层和II/III层。神经纤维中的染色强度总体降低，但P7时可见的带状模式仍然存在。出生后第二周后，新皮质中NADPH-d阳性细胞和神经纤维的模式未发生可检测到的变化。皮质的前部比后部成熟略早。这些结果表明，NADPH-d活性的发育与分层分化相关，并提示NADPH-d或NO可能在皮质神经元成熟包括功能连接建立中起重要作用。
