Postnatal development of low [Mg2+] oscillations in neocortex
Postnatal development of low [Mg2+] oscillations in neocortex
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DOI：
10.1152/jn.1997.78.4.1990
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发表时间：
1997-10-01
影响因子：
2.5
通讯作者：
Kriegstein, AR
中科院分区：
文献类型：
--
作者：
Flint, AC;Maisch, US;Kriegstein, AR
通过降低[Mg 2 +]（o）来解除N-甲基-D-天冬氨酸（NMDA）受体的阻滞，可以在成人体感皮层切片中诱导新皮层固有的一种形式的节律活动。有人建议，一个人口的固有的爆发式放电（IB）的神经元，是唯一的皮质层5可能发挥作用的节奏活动，在这些条件下看到。应用全细胞膜片钳和场电位记录方法，研究了新生大鼠皮层体感片IB细胞的发育和0 [Mg ~（2+）]振荡的发生。在出生后第12天（P12）之前，在第5层中没有遇到IB细胞，但从P13到P19，越来越多的细胞具有IB特性。在P7、P17和P19的0 [Mg 2 +]细胞中的记录表明，出生后0 [Mg 2 +]诱导的活性发生了显著变化。在P7，细胞大量显示单一动作电位序列。相比之下，在P19，细胞表现出持续0.5-5秒的有组织的节律性活动爆发，间隔相对静止的时期。在P17记录的细胞被发现比P19皮层的细胞具有更少的有组织的节律活动。在P7的0 [Mg 2 +]中进行的场电位记录显示不常见且缓慢发生的场去极化，而在P19的场电位记录包括与在成人中观察到的相同的4-12 Hz振荡的自发爆发。NE的应用，抑制5 IB层细胞的爆发式放电，显着改变了放电模式的0 [Mg 2 +]振荡在P19。这些数据表明，成熟的一种类型的节奏网络活动内在的新皮层的影响，发展的膜特性的一个单一的细胞类型。
One form of rhythmic activity intrinsic to neocortex can be induced in slices of adult somatosensory cortex by lowering [Mg2+](o) to unblock N-methyl-D-aspartate (NMDA) receptors. It has been suggested that a population of intrinsically burst-firing (IB) neurons that are unique to cortical layer 5 may play a role in the rhythmic activity seen under these conditions. Whole cell patch-clamp and field-potential recordings in slices of somatosensory cortex from neonatal rats were used to study the development of IB cells and the development of 0 [Mg2+] oscillations. IB cells were not encountered before postnatal day 12 (P12) in layer 5, but from P13 to P19 an increasing proportion of cells had IB properties. Recordings from cells at P7, P17, and P19 in 0 [Mg2+] indicate that dramatic changes occur postnatally in 0 [Mg2+]-induced activity. At P7, cells largely showed trains of single action potentials. In contrast, at P19, cells showed organized bursts of rhythmic activity lasting 0.5-5 s separated by periods of relative quiescence. Cells recorded at P17 were found to have less organized rhythmic activity than cells from P19 cortex. Field-potential recordings in 0 [Mg2+] made at P7 showed infrequent and slowly occurring field depolarizations, whereas field-potential recordings at P19 consisted of spontaneous bursts of 4-12 Hz oscillations identical to those observed in the adult. Application of NE, which inhibits burst-firing of layer 5 IB cells, significantly altered the discharge pattern of 0 [Mg2+] oscillations at P19. These data suggest that the maturation of one type of rhythmic network activity intrinsic to neocortex is influenced by the development of the membrane properties of a single cell type.