Skull Modeling Research Articles

Postneurulation rapid brain growth represents a critical time for encephalocele formation: a chick model.

Current theory regarding the pathogenesis of encephaloceles suggests that the defect occurs after neurulation is completed in which brain tissue herniates through defective mesodermal elements necessary for skull modeling. To better delineate the mechanisms of encephalocele development, we performed a variety of microsurgical manipulations in the developing cranium of the chick embryo during the postneurulation period of early rapid brain growth. The results of the study revealed that encephaloceles could be induced in 78% of chick embryos manipulated at stage 26 that had evidence of marked decompression of the primitive ventricle. On the other hand, control embryos or embryos manipulated without ventricular decompression at stage 26 did not develop encephaloceles (0 of 32). Embryos with decompression of the primitive ventricle treated at earlier stages (20-24) showed only a 5% incidence of encephaloceles. These findings suggest that there is both a critical time point during postneurulation rapid brain growth when encephaloceles are prone to occur and a mesenchymal defect associated with decompression of the primitive ventricle that must be present to induce encephaloceles.

On Early Myths and Formative Technologies: A Study of Pre‐Pottery Neolithic B Sculptures and Modeled Skulls From Jericho

AbstractDuring the last two decades, considerable interest has been expressed in the development of lime and lime plaster products in the Near Eastern Pre‐Pottery Neolithic B. The occurrences of lime products in numerous Levantine sites have raised questions concerning their methods of production, their role in the development of craft specialization, and their social and economic implications. Lime plaster was the first product that entailed the intentional chemical alteration of materials and the complete control over their properties. This was probably the reason for the wide spectrum of uses to which it was put, amongst which “daily” architectural functions appear to coexist with the symbolic or spiritual applications of this material.Amongst the variety of plaster products which appeared in the PPNB, it seems that the practice of skull plastering and sculpture production was the most “socially oriented” one, lacking any apparent relation to daily, functional use. In the present study two modeled skulls and a collection of plaster sculptures from Jericho were examined by means of thin section petrographic analysis, inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, X‐ray diffraction, and Fourier‐transform infrared spectrometry. The results of the mineralogical and chemical analyses, when compared to data obtained from similar artifacts from other sites, demonstrate pronounced intersite variability in the methods of production of the skull and sculpture modeling. The full implications of this issue are discussed in detail in the paper.