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. Author manuscript; available in PMC: 2007 Jul 26.
Published in final edited form as: Cereb Cortex. 2002 Jan;12(1):37–53. doi: 10.1093/cercor/12.1.37

Figure 2.

Figure 2

Transects of presumptive area 17 taken from the brains shown in Figure 1. An early appearing outer fibre layer (OFL) with a distinctly pallisaded appearance forms a major landmark throughout the period of development. The ventricular zone (VZ) declines progressively after E65. The subventricular zone, by contrast, increases progressively in depth and by E72 is divided into an inner subventricular zone (ISVZ) and outer subventricular zone (OSVZ) by an intruding inner fibre layer (IFL). The increase in the OSVZ is particularly important between E65 and E72 and occurs as the VZ declines. The cortical plate (CP), or its ‘pioneer plate precursor’ (Meyer et al., 2000), appears as early as E46. It increases progressively in depth and shows little change in packing density of its cells until after E88. Little in the way of the ‘presubplate’ of Kostovic and Rakic is evident in this type of preparation (Kostovic and Rakic, 1990). The subplate proper (SP), however, is evident after E55. Subsequently it increases in depth in two stages: between E65 and E72 the increase is densely cellular in character, and between E72 and E78 the increase appears to be derived mainly from a decrease in the packing density of the component cells. The marginal zone (MZ) is minimal before E65. A curiously conspicuous ‘clear layer’, marked by an asterisk, located in the deep SP, is transiently present at E72. It may be a new feature or an elaboration of the original ‘presubplate’. At later stages it appears to merge into the SP.