Preto in 1953. He soon organized the Department of Pathology, became its chairman, and began to assemble a small group of Brazilian researchers. Works While in Ribeirão Preto, Köberle noted that a promising field of research in pathology for the new department and himself could be Chagas disease, or American trypanosomiasis, which had been discovered by another Brazilian physician named Carlos Chagas, in 1910. Even though 40 years had passed since its discovery, little was known about the peculiar manifestations of the chronic phase of the disease, such as megaesophagus, megacolon, cardiomegaly, heart ventricular aneurysm, achalasia, etc., and the mechanism of the causation of these several pathologies. By making good use of the extensive caseload of fatalities due to Chagas disease in the region of Ribeirão Preto and Southern Minas Gerais, where it was endemic and widely prevalent at the time, Köberle studied initially the dilation pathologies of the digestive tract and proved, by extensively quantifying the number of neurons of the autonomic nervous system in the Auerbach's plexus, that: 1) they were strongly reduced all over the digestive tract; 2) that megacolon and megaesophagus appeared only when there was a reduction of over 80% and 55% of the number of neurons, respectively; 3) these pathologies appeared as a result of the disruption of the neurally integrated control of peristalsis (muscular annular contraction) in those parts where a strong force is necessary to impel the luminal bolus of food or feces; and 4) European idiopathic megaesophagus and Chagas megaesophagus appeared to have the same etiology, namely the degeneration of the Auerbach's myoenteric plexus. Studying the typical features of the Chagasic myocardium pathology, characterized by damage to its electrical conduction pathways, heart arrythmia, aneurysm of the ventricular apex, cardiomegalia and sudden death by ventricular fibrillation, Köberle and his group of collaborators were able to prove that they were caused also by an extensive denervation of the parasympathetic (55%) and sympathetic (35%) intrinsic cardiac nervous networks, leading to a control imbalance of contraction, cardiac failure, cardiomegalia and hypoxia. He named this constellation of effects as cardiopathia parasympathicopriva. Other less typical phenomena observed in Chagas disease, such as bronchiectasis and myelopathy were also studied by Köberle under the new prism of his neurogenic theory. Thus, with his classical and detailed scientific studies, Köberle proposed for the first time a unified and radically different (and polemical) view of the etiopathogeny of Chagas disease, characterizing