• Postnatal cortical maturation across species shows rapid synaptogenesis, cytoarchitectural differentiation, and extracellular remodeling in rat cortex, with sustained human cortex development patterns; techniques include electron microscopy and autoradiography [1], [2], [13], [17], [18].

• Synaptic connectivity and circuit formation emerge through orderly synaptogenic events and interlaminar connections, evidenced by synapse formation in rat cortex, LGN organization, and hippocampal-cortical projections [2], [6], [9], [12], [16].

• Neurochemical milieu guides development; serotonin emergence precedes neural maturation while monoamine changes accompany postnatal ontogeny, shaping regional growth and circuit formation [7], [14].

• Human cortex development and higher cognitive functions are linked to protracted maturation and substrate differentiation, with distinct timelines for structural formation and functional emergence in humans compared to animals [4], [11], [18].

• Cross-species developmental trajectories reveal conserved and divergent tempo in neurodevelopment, comparing rodent, primate, and rabbit models to human cortex formation and connectivity [8], [12], [16], [18], [19].