Fractal Scaling of Cortical Matter, Amyloid Fragmentation and Plaque Formation across Rodents and Primates

Abstract

Thermodynamic tools are well suited to connecting evolution of protein functionalities to mutations of amino acid sequences, especially for neuronal network structures. These tools enable one to quantify changes in modular structure and correlate them with corresponding changes in observable properties. Here we quantify modular rodent-primate changes in amyloid precursor protein A4 and \b{eta} amyloid fragments. These are related to changes in cortical connectivity and to the presence (absence) of plaque formation in primates (rodents). Two thermodynamic scales are used, descriptive of water/air protein unfolding (old), or fractal conformational restructuring (new). These describe complementary aspects of protein activity, at respectively higher and lower effective temperatures.