From simulations relying on detailed physiological data, cortical layer IV recurrent network topology and small thalamic input currents, a novel synchronization paradigm emerges. Coarse synchronization, where small temporal variations due to individual characteristics of neurons are still allowed, is mediated by the bursting of intrinsically non-bursting spiny stellate and basket neurons. Using advanced methods of noise removal, we concluded that the collective behavior is of low-dimensional chaotic nature. The model observations are compared with data from anesthetized cats, where three fundamental groups of neuronal firing are distinguished. Using variable thalamic input currents, the characteristic in vivo behaviors and statistical properties are reproduced. Model and experimental data lead us to the conclusion that a large group of neurons fire in terms of patterns which may have a significance in information transfer in the brain.