Horizontal and vertical dimensions of cortex, viewed from the angle of dendritic and axonal projection of single pyramidal neurons

Abstract

Cerebral cortex is a two dimensional sheet of six layers. Horizontal and vertical extents of dendritic and axonal distributions of single pyramidal neurons were visualized in the auditory cortex. Superficial pyramidal neurons had columnar plexuses of local axons in the vicinity of the cell body and at distances from it. The distant plexuses were given off vertically from horizontally coursing axons. Deep pyramidal neurons were heterogeneous in terms of the dendritic field and local axonal distribution. Each type was, however, closely related to the subcortical destination of its long-distance axons.

脳皮質は6層の2次元シートである。単一錐体ニューロンの樹状および軸索分布の水平、垂直方向への広がりを、聴覚皮質内で視覚化した。皮相錐体ニューロンは、細胞体の近くおよびそれから離れた位置で局所軸索の柱状神経叢をもつ。離れた神経叢は水平に走る軸索から垂直に出ており、深部錐体ニューロンは樹状場および局所的軸索分布からみて異質であった。しかしそれぞれのタイプは、その長い軸索の皮質下方向と密接な関係が見られた。